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Origins of Factory Physics
In 1988 we were working as consultants at the IBM circuit board plant in Austin, Texas,
helping to devise more effective production control procedures. Each time we suggested
a course of action, our clients would, quite reasonably, ask why it would work. Being
professors, we typically responsed by launching into a theoretical lecture, replete with
outlandish metaphors and impromptu graphs. After several semicoherent attempts at
explaining ourselves, our sponsor, Mr. Jack Fisher, suggested we organize the essentials
of what we were saying into a one-day course.
We did our best to put together a structured description of basic plant behavior. While
doing this, we realized that certain very fundamental relations—for example, the relation
between throughput and WIP, and several other basic results of Part II of this book—were
not well known and were not covered in any standard operations management text. Our
six offerings of the course at IBM were well received by audiences ranging from machine
operators to midlevel managers. During one offering, a participant observed, “Why, this
is like physics of the factory.” Since both of us have bachelor’s degrees in physics and
keep a soft spot in our hearts for the subject, the name stuck. Factory Physics was born.
Buoyed by the success of the IBM course, we developed a 2-day industry short course
on short-cycle manufacturing, using Factory Physics as the organizing framework. Our
focus on cycle time reduction forced us to strengthen the link between fundamental relations and practical improvement policies. Teaching to managers and engineers from a
variety of industries helped us extend our coverage to more general production environments.
In 1990, Northwestern University initiated the Master of Management in Manufacturing (MMM) program, for which we were asked to design and teach courses in management science and operations management. By this time we had enough confidence
in Factory Physics to forgo traditional problem-based and anecdote-based approaches
to these subjects. Instead, we concentrated on building intuition about basic manufacturing behavior as a means for identifying areas of leverage and comparing alternative
control policies. For completeness and historical perspective, we added coverage of conventional topics, which ultimately became Part I of this book. We received enthusiastic
support from the MMM students for the Factory Physics approach. Also, because they
had substantial and varied industry experience, they constructively challenged our ideas
and helped us sharpen our presentation.
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Preface
In 1993, after having taught the MMM courses and the industry short course several
times, we began writing out our approach in book form. This proved to be a slow process
because it revealed a number of gaps between our presentation of concepts and their
implementation in practice. Several times we had to step back and draw upon our own
research and that of many others, to develop practical discussions of key manufacturing
management problem areas. This became Part III of this book.
Factory Physics has grown a great deal since the days of our terse tutorials at IBM
and continues to expand and mature. Indeed, this third edition contains several new
developments and changes of presentation from the first edition. But while details will
change, we are confident that the fundamental insight behind Factory Physics—that there
are principles governing the behavior of manufacturing systems, and understanding them
can improve management practice—will remain the same.
Intended Audience
Factory Physics is intended for four principal audiences:
1. Manufacturing/supply chain management students: in a core operations course.
2. MBA students: in a second operations management course that would follow a
general survey course.
3. BS and MS industrial engineering students: in a production control course.
4. Manufacturing managers and engineers: for use as a reference.
Although we wrote it primarily as a text, we have been surprised and delighted by
the number of senior managers who find the book useful. Although it is neither short
nor easy, we have had many industry people contact us and say that Factory Physics is
exactly what they have been looking for. Evidently, in this environment of buzzwords
and hype, even professionals need something that brings manufacturing management
back to the basics.
How to Use this Book
After a brief introductory chapter, the book is organized into three parts: I The Lessons
of History, II Factory Physics, and III Principles in Practice. In our own teaching, we
generally cover Parts I, II, and III in order, but vary the selection of specific topics
depending on the course. One instructor we know who teaches in industry always starts
with the last chapter first. Although that chapter clearly demonstrates why we are not
professional writers of fiction, it does set the stage for what the book is trying to cover.
Regardless of the audience, we try to cover Part II completely, as it represents the
core of the Factory Physics approach. Because it makes extensive use of pull production
systems, we find it useful to cover Chapter 4, “From the JIT Revolution to Lean Manufacturing,” prior to beginning Part II. Finally, in order to provide an integrated framework
for carrying the Factory Physics concepts into the real world, we regard Chapter 13, “A
Pull Planning Framework,” as extremely important. Beyond this, the individual instructor can select historical topics from Part I, applied topics from Part III, or additional
topics from supplementary readings to meet the needs of a specific audience.
The instructor is also faced with the choice of how much mathematical depth to use.
To assist readers who want general concepts without mathematical detail, we have set
off certain sections as Technical Notes. These sections, which are labeled and indented
in the text, present justification, examples, or methodologies that rely on elementary
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Preface
mathematics (although higher than simple calculus). These sections can be skipped
completely without loss of continuity.
In teaching this material to both engineering and management students, we have
found, understandably, that management students are less interested in the mathematical
aspects of Factory Physics than are engineering students. However, it has not been our
impression that management students are averse to doing mathematics; it is math without
a concrete purpose to which they object. When faced with quantitative developments of
core manufacturing ideas, these students not only capable of grasping the math, they are
able to appreciate the practical consequences of the theory.
New to the Third Edition
The basic structure of the third edition is the same as that of the first two editions.
However, a number of enhancements have been made, including:
More problems. The number of exercises at the end of each chapter has been
increased to offer the reader a wider range of practice problems.
More examples. Almost all models are motivated with a practical application
before the development of any mathematics. Generally, these applications are
then used as examples to illustrate how the models are used.
Web support. PowerPoint presentations, case materials, spreadsheets,
derivations, and a solutions manual are now available on the Web. These are
constantly being updated as more material becomes available. Go to
http://www.factoryphysics.com for our website.
Software support: Factory Physics Inc., founded by one of the authors, provides
a “Professor Package” that allows students to use industrial grade Factory
Physics software at no charge. The software provides the means to determine
bottlenecks, compute cycle times, optimize inventories, optimize CONWIP
flows, and optimize product mix by using a linear programming application.
These applications use a common SQL database and do not require any custom
coding. The package also provides case studies and PowerPoint presentations for
the software. Because of the learning curve to use the software, the package is
best suited for a large case study or a capstone design experience. The software
is delivered over the Web at: https:/www.leanphysics.com/lpst. Interested faculty
should send an e-mail to info@factoryphysics.com.
Science of manufacturing: Chapter 6 has been revised to provide a formal
scientific basis for the Factory Physics approach. By describing the essential
production problem as one of aligning transformation with demand, we provide
a framework for the key results of Part II, including the need for buffering
variability. We hope that this framework makes it easier to view the collection of
concepts and models presented in Chapters 7 to 9 as a coherent whole.
Metrics: To connect our science-based approach to operations management to
the “balanced score card” methods popular in practice, we have developed a set
of Factory Physics metrics in Chapter 9. These consist of efficiency measures for
the three variability buffers and support our definition of lean as “achieving” the
fundamental objective with minimal buffering cost.”
Variability pooling: Chapter 8 introduces the fundamental idea that variability
from independent sources can be reduced by combining the sources. This basic
idea is used throughout the book to understand disparate practices, such as how
safety stock can be reduced by stocking generic parts, how finished goods
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inventories can be reduced by “assembling to order,” and how elements of push
and pull can be combined in the same system.
r Sharper variability results: Several of the laws in Chapter 9, “The Corrupting
Influence of Variability,” have been restated in clearer terms, and some important
new laws, corollaries, and definitions have been introduced. The result is a more
complete science of how variability degrades performance in a production
system.
r Optimal batch sizes: Chapters 9 and 15 extend the Factory Physics analysis of
the effects of batching to a normative method for setting batch sizes to minimize
cycle times in multiproduct systems with setups and discuss implications for
production scheduling.
r Shop floor control: Chapter 14 has been modified to describe the parallels and
differences between MRP and CONWIP as job release mechanisms. This
discussion will help managers of systems making use of MRP find ways to
incorporate the operational benefits of pull.
r Inventory/order interface: The discussion of how “push” and “pull” coexist
within most production/supply chain systems has been expanded and refined.
The concept of the inventory/order interface has been introduced to describe the
point in a flow where the system shifts from make-to-stock to make-to-order.
r Supply chain management: Chapters 3 and 5 now describe how materials
requirements planning (MRP) evolved into enterprise resources planning (ERP)
and then supply chain management (SCM). Chapter 17 makes use of the
inventory concepts of Chapter 2 to develop the concepts, tools, and practices that
underlie effective supply chain management.
r Quality management: Chapter 12 has been expanded to cover both the statistical
foundations and organizational elements of the Six Sigma approach to quality
and now includes some laws concerning the behavior of production lines in which
personnel capacity is an important constraint along with equipment capacity.
Acknowledgments
Since our thinking has been influenced by too many people to allow us to mention them
all by name, we offer our gratitude (and apologies) to all those with whom we have
discussed Factory Physics over the years. In addition, we acknowledge the following
specific contributions.
We thank the key people who helped us shape our ideas on Factory Physics: Jack
Fisher of IBM, who originated this project by first suggesting that we organize our
thoughts on the laws of plant behavior into a consistent format; Joe Foster, former adviser who got us started at IBM; Dave Woodruff, former student and lunch companion
extraordinaire, who played a key role in the original IBM study and the early discussions (arguments) in which we developed the core concepts behind our approach; Karen
Donohue, Izak Duenyas, Valerie Tardif, and Rachel Zhang, former students who collaborated on our industry projects and upon whose research portions of this book are
based; Yehuda Bassok, John Buzacott, Eric Denardo, Brian Deuermeyer, Steve Graves,
Uday Karmarkar, Steve Mitchell, George Shanthikumar, Rajan Suri, Joe Thomas, and
Michael Zazanis, colleagues whose wise counsel and stimulating conversation produced
important insights in this book. We also acknowledge the National Science Foundation,
whose consistent support made much of our own research possible.
Preface
xi
We are particularly grateful to those who tested the first versions of the book (or portions of it) in the classroom and provided us with essential feedback that helped eliminate
many errors and rough spots: Karla Bourland (Dartmouth), Izak Duenyas (Michigan),
Paul Griffin (Georgia Tech), Steve Hackman (Georgia Tech), Michael Harrison (Stanford), Phil Jones (Iowa), S. Rajagopalan (USC), Jeff Smith (Auburn), Marty Wortman
(Texas A & M). We thank the many students who had to put up with typo-ridden drafts
during the testing process, especially our own students in Northwestern’s Master of
Management in Manufacturing (MMM) program in BS/MS-level industrial engineering courses at Northwestern and Texas A&M, and in MBA courses in Northwestern’s
Kellogg Graduate School of Management.
We give special thanks to the reviewers of the original manuscript, Suleyman Tefekci
(University of Florida), Steve Nahmias (Santa Clara University), David Lewis (University of Massachusetts—Lowell), Jeffrey L. Rummel (University of Connecticut),
Pankaj Chandra (McGill University), Aleda Roth (Clemson University), K. Roscoe Davis
(University of Georgia), and especially Michael Rothkopf, whose thoughtful comments
greatly improved the quality of our ideas and presentation. We also thank Mark Bielak
who assisted us in our first attempt to write fiction (in Chapter 19).
In addition to those who helped us produce the first edition, many of whom also
helped us on the second and third editions, we are grateful to individuals who had particular influence on the revision. We acknowledge our deep appreciation of the people
whose ideas and suggestions helped us deepen our understanding of Factory Physics: Jeff
Alden (General Motors), John Bartholdi (Georgia Tech), Max Bataille (Baxter Healthcare), Jeff Bell (Concordant Industries), Corey Billington (Hewlett-Packard), Dennis E.
Blumenfeld (General Motors), Sunil Chopra (Northwestern University), Mark Daskin
(Northwestern University), Greg Diehl (Network Dynamics), John Fowler (Arizona State
University), Rob Herman (Alcoa), Bill Jordan (General Motors), Hau Lee (Stanford University), John Mittenthal (University of Alabama), Giulio Noccioli (Baxter Healthcare),
Ed Pound (Factory Physics, Inc.), Lee Schwarz (Purdue University), Chandra Sekhar
(Baxter Healthcare), Alexander Shapiro (Georgia Tech), Kalyan Singhal (University of
Maryland), Tom Tirpak (Motorola), Mark Van Oyen (University of Michigan), Jan Van
Mieghem (Northwestern University), William White (Bell & Howell), Eitan Zemel (New
York University), and Paul Zipkin (Duke University).
We would like to thank the reviewers of the first edition whose suggestions helped
shape the second edition: Diane Bailey (Stanford University), Charles Bartlett (Polytechnic University), Guillermo Gallego (Columbia University), Marius Solomon (Northeastern University), M. M. Srinivasan (University of Tennessee), Ronald S. TibbenLembke (University of Nevada, Reno), and Rachel Zhang (University of Michigan). We
are also very grateful to the reviewers of the second edition, whose comments and criticisms helped us further refine our vision of factory physics: William Giauque (Brigham
Young University), Izak Duenyas (University of Michigan), Mandyam Srinivasan (University of Tennessee), Esma Gel (Arizona State University), Erhan Kutanoglu (University
of Texas Austin), Michael Kay (North Carolina State University), Onur Ulgen (University of Michigan, Dearbon), and Terry Harrison (Penn State University).
Finally, we thank the editorial staff: Dick Hercher, Executive Editor, who kept us
going by believing in this project for years on the basis of all talk and no writing and
for his enormous patience in the face of our painfully slow revisions; Gail Korosa,
Christina Sanders, and Katie Jones, Development Editors who recruited reviewers and
applied polite pressure to meet deadlines, and Project Editors Mary Conzachi, Kim
Hooker, and Lori Koetters who directed the three editions of Factory Physics through
the bookmaking process.
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Factory Physics?
PART I
THE LESSONS OF HISTORY
1
2
3
4
5
14
Manufacturing in America
Inventory Control: From EOQ to ROP
The MRP Crusade
49
114
From the JIT Revolution to Lean Manufacturing
What Went Wrong
155
176
PART II
FACTORY PHYSICS
6
7
8
9
10
11
12
196
A Science of Manufacturing
227
Basic Factory Dynamics
Variability Basics
264
The Corrupting Influence of Variability
Push and Pull Production Systems
306
356
The Human Element in Operations Management
Total Quality Manufacturing
384
399
PART III
PRINCIPLES IN PRACTICE
13
14
15
16
17
18
19
A Pull Planning Framework
Aggregate and Workforce Planning
Supply Chain Management
Capacity Management
553
603
648
Synthesis-Pulling It All Together
References
Index
434
481
Production Scheduling 516
Shop Floor Control
670
697
709
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Factory Physics?
0.1
The Short Answer
1
0.2
The Long Answer
1
0.2.1
Focus: Manufacturing Management
0.2.2
Scope: Operations
0.2.3
Method: Factory Physics
6
0.2.4
Perspective: Flow Lines
9
0.3
T
3
An Overview of the Book
11
PART I
THE LESSONS OF HISTORY
1
14
Manufacturing in America
1.1
Introduction
1.2
The American Experience
14
1.3
The First Industrial Revolution
15
17
1.3.1
The Industrial Revolution in America
1.3.2
The American System of Manufacturing
1.4
The Second Industrial Revolution
1.4.1
The Role of the Railroads
1.4.2
Mass Retailers
1.4.3
Andrew Carnegie and Scale
1.4.4
Henry Ford and Speed
1.5
18
19
20
21
22
Scientific Management
23
24
26
1.5.1
Frederick W. Taylor
1.5.2
Planning versus Doing
1.5.3
Other Pioneers of Scientific Management
1.5.4
The Science in Scientific Management
1.6
27
30
31
32
The Rise of the Modem Manufacturing Organization
1.6.1
Du Pont, Sloan, and Structure
33
33
1.6.2
Hawthorne and the Human Element
1.6.3
Management Education
34
36
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Contents
1.7 Peak, Decline, and Resurgence of American Manufacturing
1.7.1 The Golden Era 38
1.7.2 Accountants Count and Salesmen Sell 38
1.7.3 The Professional Manager 41
1.7.4 Recovery and Globalization of Manufacturing 43
1.8 The Future 44
Discussion Points
46
Study Questions
47
2
Inventory Control: From EOQ to ROP
49
2.1 Introduction 49
2.2 The Economic Order Quantity Model 50
2.2.1 Motivation 50
2.2.2 The Model 50
2.2.3 The Key Insight of EOQ 53
2.2.4 Sensitivity 55
2.2.5 EOQ Extensions 57
2.3 Dynamic Lot Sizing 58
2.3.1 Motivation 58
2.3.2 Problem Formulation 59
2.3.3 The Wagner-Whitin Procedure 60
2.3.4 Interpreting the Solution 64
2.3.5 Caveats 65
2.4 Statistical Inventory Models 66
2.4.1 The News Vendor Model 67
2.4.2 The Base Stock Model 71
2.4.3 The (Q, r) Model 78
2.5 Conclusions 91
Appendix 2A Basic Probability 93
Appendix 2B Inventory Formulas 105
Study Questions
107
Problems
108
3
The MRP Crusade
1 14
3.1 Material Requirements Planning-MRP
3.1.1 The Key Insight ofMRP 114
3.1.2 Overview ofMRP 115
3.1.3 MRP Inputs and Outputs 119
114
3.1.4 The MRP Procedure 121
3.1.5 Special Topics in MRP 126
3.1.6 Lot Sizing in MRP 129
3.1.7 Safety Stock and Safety Lead Times 133
3.1.8 Accommodating Yield Losses 135
3.1.9 Problems in MRP 135
3.2 Manufacturing Resources Planning-MRP II 139
3.2.1 The MRP IIHierarchy 140
3.2.2 Long-Range Planning 141
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Contents
3.2.3 Intermediate Planning 141
3.2.4 Short-Term Control 145
3.3 Enterprise Resources Planning and Supply Chain Management
3.3.1 ERP and SCM 148
3.3.2 Advanced Planning Systems 149
3.4 Conclusions 149
Study Questions
150
Problems
151
4
From the JIT Revolution to Lean Manufacturing
4.1 The Origins of JIT 155
4.2 JIT Goals 157
4.3 The Environment as a Control 158
4.4 Implementing JIT 160
4.4.1 Production Smoothing-Heijunka 160
4.4.2 Capacity Buffers 162
4.4.3 Setup Reduction 162
4.4.4 Cross-Training and Plant Layout 163
4.4.5 Less Work In Process 165
4.5 Total QualityManagement 165
4.5.1 Driving Forces forHigher Quality 165
4.5.2 Quality Principles from JIT 166
4.5.3 The West Strikes Back-ISO 9000 167
4.6 Pull Systems and Kanban 168
4.6.1 Classic Kanban 168
4.6.2 Other Pull Systems 170
4.6.3 Kanban and Base Stock Systems 170
4.7 Goodbye JIT,Hello Lean 171
4.7.1 LeanManufacturing 171
4.7.2 Six Sigma and Beyond 171
4.8 The Lessons of JIT/Lean and TQMlSix Sigma
Discussion Point
174
Study Questions
174
5
VVhatVVentVVrong?
176
5.1 The Problem 176
5.2 The Solution 180
5.3 Scientific Management 181
5.4 The Rise of the Computer 183
5.5 Other "Scientific" Approaches 187
5.5.1 Business Process Re-engineering
5.5.2 Lean Manufacturing 188
5.5.3 Six Sigma 189
5.6 W here to fromHere? 190
Discussion Points
192
Study Questions
192
188
172
155
147
xviii
Contents
PART II
FACTORY PHYSICS
6
A Science of Manufacturing
196
6.1 The Seeds of Science 196
6.1.1 A Blizzard of Buzzwords 196
6.1.2 W hy Science? 197
6.2 Formal Roots 201
6.2.1 W hat Is Science? 201
6.2.2 "Formal Cause" of Manufacturing Systems 202
6.2.3 Models-Prescriptive and Descriptive 204
6.3 Strategic and Operational Objectives
6.3.1 Fundamental Objective 206
6.3.2
6.3.3
205
206
208
Hierarchical Objectives
Strategic Positioning
6.4 Models and Performance Measures 213
6.4.1 Cost Accounting 214
6.4.2 Tactical and Strategic Modeling 217
6.4.3 Considering Risk 218
6.5 A Methodology for Improvement 219
6.6 Conclusions 221
Appendix 6A
Study Questions
Problems
7
224
225
Basic Factory Dynamics
227
7.1 Introduction 227
7.2 Definitions and Parameters 228
7.2.1 Definitions 228
7.2.2 Parameters 231
7.2.3 Examples 232
7.3 Simple Relationships 235
7.3.1 Best-Case Performance 235
7.3.2 Worst-Case Performance 241
7.3.3 Practical Worst-Case Performance
7.3.4
Bottleneck Rates and Cycle Time
7.3.5
Internal Benchmarking
7.4
244
248
250
253
Labor-Constrained Systems
7.4.1
Ample Capacity Case
7.4.2
Full Flexibility Case
7.4.3
CONWIP Lines with Flexible Labor
254
255
7.4.4 Flexible Labor System Design
7.5 Conclusions 258
Study Questions
Problems
223
Activity-Based Costing (ABC)
259
259
Intuition-Building Exercises
262
257
256
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Contents
8
8.1
Introduction
8.2
Variability and Randomness
264
265
8.2.1
The Roots of Randomness
8.2.2
Probabilistic Intuition
8.3
265
267
Process Time Variability
268
8.3.1
Measures and Classes of Variability
8.3.2
Low and Moderate Variability
269
8.3.3
Highly Variable Process Times
270
8.4
Causes of Variability
268
271
8.4.1
Natural Variability
8.4.2
Variability from Preemptive Outages (Breakdowns)
8.4.3
Variability from Nonpreemptive Outages
271
8.4.4
Variability from Rework
8.4.5
Summary of Variability Formulas
8.5
Flow Variability
277
277
8.5.1
Characterizing Variability in Flows
Demand Variability and Flow Variability
8.5.3
Batch Arrivals and Departures
281
Variability Interactions-Queueing
282
8.6.1
Queueing Notation and Measures
8.6.2
Fundamental Relations
278
281
283
284
8.6.3
The MIMll Queue
8.6.4
Performance Measures
8.6.5
Systems with General Process and Interarrival Times
8.6.6
Parallel Machines
8.6.7
Parallel Machines and General Times
8.7
Effects of Blocking
284
287
290
8.7.1
The MIMl11b Queue
General Blocking Models
Variability Pooling
292
8.8.1
Batch Processing
Safety Stock Aggregation
8.8.3
Queue Sharing
8.9
Conclusions
Problems
296
298
8.8.2
Study Questions
299
300
300
301
302
303
The Corrupting Influence of Variability
9.1
Introduction
306
306
9.1.1
Can Variability Be Good?
9.1.2
Examples of Good and Bad Variability
9.2
291
292
8.7.2
8.8
Variability Laws
272
275
277
8.5.2
8.6
9
264
Variability Basics
306
308
9.2.1
Buffering Examples
9.2.2
Pay Me Now or Pay Me Later
309
9.2.3
Flexibility
9.2.4
Organizational Learning
313
314
311
307
288
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Contents
9.3
Flow Laws
314
9.3.1
Product Flows
9.3.2
Capacity
9.3.3
Utilization
9.3.4
Variability and Flow
9.4
314
315
317
Batching Laws
318
318
9.4.1
Types of Batches
9.4.2
Process Batching
320
9.4.3
Transfer Batches
324
9.5
Cycle Time
319
327
9.5.1
Cycle Time at a Single Station
9.5.2
Assembly Operations
9.5.3
Line Cycle Time
9.5.4
Cycle Time, Lead Time, and Service
9.6
329
Performance and Variability
9.6.1
9.7
Measures of Manufacturing Performance
Diagnostics and Improvements
Increasing Throughput
340
Reducing Cycle Time
343
9.7.3
Improving Customer Service
Conclusions
Study Questions
346
347
349
Intuition-Building Exercises
10
349
351
Push and Pull Production Systems
10.1
Introduction
10.2
Perceptions of Pull
10.2.1
10.3
356
The Key Distinction between Push and Pull
The Magic of Pull
359
Reducing Manufacturing Costs
10.3.2
Reducing Variability
10.3.3
Improving Quality
Maintaining Flexibility
10.3.5
Facilitating Work Ahead
CONWIP
361
362
363
363
10.4.1
Basic Mechanics
10.4.2
Mean-Value Analysis Model
364
Observability
10.5.2
Efficiency
369
10.5.3
Variability
371
10.5.4
Robustness
372
369
369
Comparisons of CONWIP with Kanban
10.6.1
Card Count Issues
373
375
10.6.2
Product Mix Issues
10.6.3
People Issues
10.6.4
The Inventory/Order Interface
10.7
365
Comparisons of CONWIP with MRP
10.5.1
10.6
359
360
10.3.4
10.5
356
356
10.3.1
10.4
333
340
9.7.1
Problems
331
333
9.7.2
9.8
327
328
Conclusions
380
376
377
373
357
Contents
xxi
Study Questions
Problems
11
381
381
The Human Element in Operations Management
11.1
Introduction
11.2
Basic Human Laws
385
11.2.1
The Foundation of Self-Interest
11.2.2
The Fact of Diversity
11.2.3
The Power of Zealotry
390
11.2.4
The Reality of Burnout
392
11.3
Planning versus Motivating
393
11.4
Responsibility and Authority
11.5
Summary
Discussion Points
394
397
398
399
Total Quality Manufacturing
12.1
Introduction
399
12.1.1
The Decade of Quality
12.1.2
A Quality Anecdote
12.1.3
The Status of Quality
12.2
Views of Quality
399
400
401
402
12.2.1
General Definitions
12.2.2
Internal versus External Quality
12.3
402
Statistical Quality Control
SQC Approaches
12.3.2
Statistical Process Control
12.3.3
SPC Extensions
Six Sigma
404
405
408
409
12.4.1
Statistical Foundations
12.4.2
DMAIC
12.4.3
Organizational Structure
12.5
410
413
Quality and Operations
413
414
12.5.1
Quality Supports Operations
416
12.5.2
Operations Supports Quality
422
12.6
Quality and the Supply Chain
424
12.6.1
A Safety Lead Time Example
12.6.2
Purchased Parts in an Assembly System
12.6.3
Vendor Selection and Management
12.7
Conclusions
Study Questions
Problems
428
428
429
PART III
PRINCIPLES IN PRACTICE
13
402
404
12.3.1
12.4
385
387
396
Study Questions
12
384
A Pull Planning Framework
l3.1
Introduction
434
434
424
427
425
384
xxii
Contents
13.2
Disaggregation
Time Scales in Production Planning
435
13.2.2
Other Dimensions of Disaggregation
437
13.2.3
Coordination
13.3
Forecasting
439
440
13.3.1
Causal Forecasting
13.3.2
Time Series Forecasting
13.3.3
The Art of Forecasting
441
444
456
13.4
Planning for Pull
13.5
Hierarchical Production Planning
456
13.5.1
Capacity/Facility Planning
13.5.2
Workforce Planning
463
13.5.3
Aggregate Planning
465
459
461
13.5.4
WIP and Quota Setting
466
13.5.5
Demand Management
469
13.5.6
Sequencing and Scheduling
13.5.7
Shop Floor Control
13.5.8
Real-Time Simulation
Production Tracking
Conclusions
469
470
13.5.9
13.6
471
471
472
Appendix 13A
A Quota-Setting Model
Study Questions
475
Problems
14
435
13.2.1
476
Shop Floor Control
481
14.1
Introduction
14.2
General Considerations
481
484
14.2.1
Gross Capacity Control
14.2.2
Bottleneck Planning
14.2.3
Span of Control
14.3
Basic CONWIP
484
486
488
CONWIP Configurations
14.3.1
473
488
489
14.3.2
More Complex CONWIP Systems
14.3.3
Tandem CONWIP Lines
14.3.4
Shared Resources
14.3.5
Multiple-Product Families
499
14.3.6
CONWIP Assembly Lines
5 00
14.4
489
496
497
Other Pull Mechanisms
501
14.4.1
Kanban
14.4.2
Pull-from-the-Bottleneck Methods
5 03
14.4.3
Shop Floor Control and Scheduling
5 04
14.5
502
Production Tracking
505
14.5.1
Statistical Throughput Control
505
14.5.2
Long-Range Capacity Tracking
5 08
14.6
Conclusions
510
Appendix 14A
Statistical Throughput Control
Study Questions
513
Problems
5 13
5 12
xxiii
Contents
15
15.1
Meeting Due Dates
516
15.1.2
Maximizing Utilization
15.1.3
Reducing WIP and Cycle Times
15 .2
5 17
Review of Scheduling Research
15.2.1
MRP, MRP II, and ERP
15 .2.2
Classic Machine Scheduling
15.2.3
Dispatching
15.2.4
Why Scheduling Is Hard
15.2.5
Good News and Bad News
15.2.6
Scheduling in Practice
15.3
5 18
5 19
5 19
5 19
521
5 22
5 25
5 26
5 29
Linking Planning and Scheduling
15.3.1
Optimal Batching
5 30
15.3.2
Due Date Quoting
5 35
Bottleneck Scheduling
5 38
15.4
15.4.1
CONWIP Lines without Setups
15.4.2
Single CONWIP Lines with Setups
15.4.3
Bottleneck Scheduling Results
15.5
Diagnostic Scheduling
15.5.1
15.6
5 39
5 43
Types of Schedule Infeasibility
5 44
Production Scheduling in a Pull Environment
Schedule Planning, Pull Execution
15.6.2
Using CONWIP with MRP
Conclusions
Study Questions
Problems
5 48
5 49
550
16.1
Introduction
16.2
Basic Aggregate Planning
A Simple Model
555
16.2.2
An LP Example
556
Product Mix Planning
554
5 64
16.3.1
Basic Model
16.3.2
A Simple Example
16.3.3
Extensions to the Basic Model
565
Workforce Planning
5 66
An LP Model
16.4.2
A Combined APfWP Example
16.4.3
Modeling Insights
16.5
Conclusions
Problems
5 76
5 88
5 96
5 96
Supply Chain Management
17.1
Introduction
5 78
5 88
Linear Programming
Study Questions
5 71
5 76
16.4.1
Appendix 16A
553
553
16.2.1
16.4
5 47
548
Aggregate and Workforce Planning
16.3
5 40
5 43
15.6.1
15.7
17
5 16
Goals of Production Scheduling
15.1.1
16
516
Production Scheduling
603
603
5 90
5 47
xxiv
Contents
17.2
17.2.2
Work in Process
Finished Goods Inventory
17.2.4
Spare Parts
604
606
607
607
Managing Raw Materials
17.3.1
Visibility Improvements
17.3.2
ABC Classification
17.3.3
Just-in-Time
17.3.4
Setting Safety Stock/Lead Times for Purchased Components
17.3.5
Setting Order Frequencies for Purchased Components
17.4
Managing WIP
608
608
609
Reducing Queueing
17.4.2
Reducing Wait-for-Batch W IP
619
17.4.3
Reducing Wait-to-Match WIP
620
17.5
Managing FGI
17.6
Managing Spare Parts
617
621
623
17.6.1
Stratifying Demand
17.6.2
Stocking Spare Parts for Emergency Repairs
623
System Configurations
17.7.2
Performance Measures
17.7.3
The Bullwhip Effect
17.7.4
An Approximation for a Two-Level System
Conclusions
645
Study Questions
645
633
634
638
646
Capacity Management
18.1
632
643
Discussion Point
Problems
623
631
Multiechelon Supply Chains
17.7.1
17.8
610
616
17.4.1
17.7
18
604
Raw Materials
17.2.3
17.3
604
Reasons for Holding Inventory
17.2.1
648
648
The Capacity-Setting Problem
648
18.1.1
Short-Term and Long-Term Capacity Setting
18.1.2
Strategic Capacity Planning
18.1.3
Traditional and Modem Views of Capacity Management
18.2
Modeling and Analysis
649
653
18.2.1
Example: A Minimum Cost, Capacity-Feasible Line
18.2.2
Forcing Cycle Time Compliance
657
18.3
Modifying Existing Production Lines
658
18.4
Designing New Production Lines
659
18.4.1
The Traditional Approach
18.4.2
A Factory Physics Approach
18.4.3
Other Facility Design Considerations
18.5
660
Capacity Allocation and Line Balancing
18.5.1
Paced Assembly Lines
18.5.2
Unbalancing Flow Lines
18.6
659
Conclusions
662
663
663
Appendix 18A
The Line-of-Balance Problem
Study Questions
668
Problems
668
661
662
665
655
651
610
Contents
19
xxv
Synthesis-Pulling It All Together
19.1
The Strategic Importance of Details
19.2
The Practical Matter of Implementation
19.2.1
A Systems Perspective
19.2.2
Initiating Change
19.3
Focusing Teamwork
671
672
673
19.3.1
Pareto's Law
19.3.2
Factory Physics Laws
674
A Factory Physics Parable
677
19.4
19.4.1
674
Hitting the Trail
677
19.4.2
The Challenge
19.4.3
The Lay of the Land
19.4.4
Teamwork to the Rescue
683
19.4.5
How the Plant Was Won
690
19.4.6
Epilogue
19.5
References
Index
670
709
The Future
697
691
692
680
680
670
671
C
H
0
A
P
T
E
R
Factory Physics?
Perfection of means and confusion of goals seem to characterize our age.
Albert Einstein
0.1
The Short Answer
What is Factory Physics, and why should one study it?
Briefly, Factory Physics is a systematic description of the underlying behavior of
manufacturing systems. Understanding it enables managers and engineers to work with
the natural tendencies of manufacturing systems to
1. Identify opportunities for improving existing systems.
2. Design effective new systems.
3. Make the trade-offs needed to coordinate policies from disparate areas.
0.2
The Long Answer
The above definition of Factory Physics is concise, but leaves a great deal unsaid. To
provide a more precise description of what this book is all about, we need to describe
our focus and scope, define more carefully the meaning and purpose of Factory Physics,
and place these in context by identifying the manufacturing environments on which we
will concentrate.
0.2.1 Focus: Manufacturing Management
To answer the question of why one should study Factory Physics, we must begin by
answering the question of why one should study manufacturing at all. After all, one
frequently hears that the United States is moving to a service economy, in which the
manufacturing sector will represent an ever-shrinking component. On the surface this
appears to be true: Manufacturing employed as much as 40 percent of the U.S. workforce
in the 1940s, but less than 13 percent by 2006.
1
2
Chapter 0
Factory Physics?
But there are two possible explanations for this. One is that manufacturing is being
offshored by moving operations to lower-cost labor markets. The second is that it is
being automated through investments that make labor more productive. Which one is
actually occuring has important consequences for the role of manufacturing managers,
the economy, and for society.
If manufacturing is being offshored, as Cohen and Zysman (1987) warned, the economic impact could be dire. The reason, they argued, is that many jobs normally classified
as service (e.g., design and engineering services, payroll, inventory and accounting services, financing and insuring, repair and maintenance of plant and machinery, training
and recruiting, testing services and labs, industrial waste disposal, engineering support
services, trucking of semifinished goods, etc.) are tightly linked to manufacturing. If
manufacturing operations were moved to another country, these jobs would tend to follow. They estimated that the number of tightly linked jobs could be as high as twice the
number of direct manufacturing jobs, implying that as much as half of the American
economy was strongly dependent on manufacturing. Clearly, a major shift in such a
big piece of the economy would have major impacts on employment, wages, and living
standards nationwide.
Fortunately, however, despite a great deal of political rhetoric to the contrary, a mass
migration of manufacturing jobs does not seem to have occurred. Figure 0.1 shows that
total manufacturing employment has remained largely stable since WWII, albeit with
dips during recessions, including that of 2001. Simultaneously, manufacturing output
has grown steadily and dramatically, although again with dips in recessions.
This sugggests that the long-term decline in the percentage of people working in
the manufacturing sector is primarily due to productivity increases. These have made it
possible to increase manufacturing output without increasing the size of the workforce.
Since the overall workforce has grown dramatically, direct manufacturing employees
have steadily become a smaller percentage of the workforce. But, since manufacturing
output has continued to rise, tightly linked jobs have presumably remained in the economy
and are accounting for a substantial part of the overall job growth in the postwar era.
Manufacturing
employment and output,
1939–2006.
20000
(Source: Bureau of Labor
Statistics)
120
100
80
15000
60
10000
40
5000
20
Total employment in manufacturing
Manufacturing output
0
0
39
19
44
19
49
19
19
54
59
19
64
19
69
19
74
19
Year
79
19
84
19
89
19
94
19
99
19
04
20
Output (index, 1997 = 100)
25000
Employment (1000s)
Figure 0.1
Chapter 0
Factory Physics?
3
Of course, one might argue that the short-term decline in the absolute number of
American manufacturing jobs since the mid-1990s is due to a recent offshoring trend.
However, the data does not support this either. While the United States experienced an
11 percent reduction in manufacturing employment between 1995 and 2002, China had
a 15 percent reduction, Brazil had a 20 percent reduction, and globally the decrease was
exactly the same as in the United States—11 percent (Drezner 2004). Hence, it appears
that we are still witnessing a worldwide productivity boom in manufacturing similar
to the one that revolutionized agriculture in the early years of the 20th century. During
the so-called Green Revolution, employment in agriculture declined from 29 percent of
the workforce in 1929 to less than 3 percent by 1985. If the current “Lean Revolution”
in manufacturing continues, we can expect further increases in manufacturing output
accompanied by a decline in total factory jobs around the globe.
The management implications of this are clear. More than ever, manufacturing is a
game of making more with less. Manufacturing managers must continue to find ways to
meet continually elevating customer expectations with ever higher levels of efficiency.
Because the pressure of global competition leaves little room for error and because
manufacturing is becoming increasingly complex, both technologically and logistically,
manufacturing managers must be more technically literate than ever before.
The economic implications of the Lean Revolution are less unclear. When jobs
in agriculture were automated, they were replaced by higher-productivity, higher-pay
manufacturing jobs. It would be nice if manufacturing jobs lost or not created as a result
of productivity advances were replaced by higher-productivity, higher-pay service jobs.
But, while high-pay service jobs exist, as of April 2007 average hourly compensation
was still higher in goods-producing firms than in service-producing firms by a margin of
$18.00 to $16.26 (Bureau of Labor Statistics 2007). This discrepancy may account for the
recent stagnation in growth of real wages. Specifically, from 1970 to 1985 productivity
grew at a pace of 1.9 percent per year and real wages grew 0.87 percent per year, but
from 1985 to 1996 growth in productivity was 2.5 percent while wage growth was only
0.26 percent per year. Reversing this trend may require applying the analogies of “lean”
manufacturing to the service sector to accelerate productivity growth.
Finally, while speaking of manufacturing as a monolithic whole may continue to
make for good political rhetoric, it is important to remember the reality is that performance of the manufacturing sector is achieved one firm at a time. Certainly a host of
general policies, from tax codes to educational initiatives, can help the entire sector
somewhat; the ultimate success of each individual firm is fundamentally determined by
the effectiveness of its management. Hence, quite literally, our economy, and our very
way of life in the future, depends on how well American manufacturing managers adapt
to the new globally competitive environment and evolve their firms to keep pace.
0.2.2 Scope: Operations
Given that the study of manufacturing is worthwhile, how should we study it? Our focus
on management naturally leads us to adopt the high-level orientation of “big M” manufacturing, which includes product design, process development, plant design, capacity
management, product distribution, plant scheduling, quality control, workforce organization, equipment maintenance, strategic planning, supply chain management, interplant
coordination, as well as direct production—“little m” manufacturing—functions such
as cutting, shaping, grinding, and assembly.
Of course, no single book can possibly cover all big M manufacturing. Even if
one could, such a broad survey would necessarily be shallow. To achieve the depth
4
Chapter 0
Factory Physics?
needed to promote real understanding, we must narrow our scope. However, to preserve
the “big picture” management view, we cannot restrict it too much; highly detailed
treatment of narrow topics (e.g., the physics of metal cutting) would constitute such a
narrow viewpoint that, while important, would hardly be suitable for identifying effective
management policies. The middle ground, which represents a balance between high-level
integration and low-level details, is the operations viewpoint.
In a broad sense, the term operations refers to the application of resources (capital,
materials, technology, and human skills and knowledge) to the production of goods and
services. Clearly, all organizations involve operations. Factories produce physical goods.
Hospitals produce surgical and other medical procedures. Banks produce checking account transactions and other financial services. Restaurants produce food and perhaps
entertainment. And so on.
The term operations also refers to a specific function in an organization, distinct
from other functions such as product design, accounting, marketing, finance, human resources, and information systems. Historically, people involved in the operations function
are housed in departments with names like production control, manufacturing engineering, industrial engineering, and planning, and are responsible for the activities directly
related to the production of goods and services. These typically include plant scheduling, inventory control, quality assurance, workforce scheduling, materials management,
equipment maintenance, capacity planning, and whatever else it takes to get product out
the door.
In this book, we view operations in the broad sense rather than as a specific function.
We seek to give general managers the insight necessary to sift through myriad details
in a production system and identify effective policies. The operations view focuses on
the flow of material through a plant, and thereby places clear emphasis on most of the
key measures by which manufacturing managers are evaluated (throughput, customer
service, quality, cost, investment in equipment and materials, labor costs, efficiency, etc.).
Furthermore, by avoiding the need for detailed descriptions of products or processes,
this view concentrates on generic manufacturing behavior, which makes it applicable to
a wide range of specific environments.
The operations view provides a unifying thread that runs through all the various
big-M manufacturing issues. For instance, operations and product design are linked in
that a product’s design determines how it must flow through a plant and how difficult
it will be to make. Adopting an operations viewpoint in the design process therefore
promotes design for manufacturability. In the same fashion, operations and strategic
planning are closely tied, since strategic decisions determine the number and types of
products to be produced, the size of the manufacturing facilities, the degree of vertical
integration, and many other factors that affect what goes on inside the plant. Embedding
a concern for operations in strategic decision making is essential for ensuring feasible
plans. Other manufacturing functions have analogous relationships to operations, and
hence can be coordinated with the actual production process by addressing them from
an operations viewpoint.
The traditional field in which operations are studied is called operations management (OM). However, OM is broader than the scope of this book, since it encompasses
operations in service, as well as manufacturing, organizations. Just as our operations
scope covers only part of (big M) manufacturing, our manufacturing focus includes only
part of operations management. In short, the scope of this book can be envisioned as the
intersection between OM and manufacturing, as illustrated in Figure 0.2.
The operations view of manufacturing may seem a somewhat technical perspective
for a management book. But this is not accidental. Some degree of technicality is required
Chapter 0
Factory Physics?
5
Figure 0.2
Manufacturing and
operations management.
Operations Management
(service, transportation
retail, manufacturing, etc.)
Manufacturing Operations
Manufacturing
(manufacturing engineering,
product/process design,
production control, etc.)
just to accurately describe manufacturing behavior in operations terms. More important,
however, is the reality that in today’s environment, manufacturing itself is technical.
Intense global competition is relentlessly raising market standards, causing seemingly
small details to take on large strategic importance. For example, quality acceptable to
customers in the 1970s may have been possible with relatively unsophisticated systems.
But to meet customer expectations and comply with standards common for vendor certification today is virtually impossible without rigorous quality systems in place. Similarly,
it was not so long ago when customer service could be ensured by maintaining large
inventories. Today, rapid technological change and smaller profit margins make such
a strategy uneconomical—literally forcing companies into the tighter control systems
necessary to run with low-inventory levels. These shifts are making operations a more
integral, and more technical, component of running a manufacturing business.
The trends of the 1990s may make it appear that the importance of operations is a
new phenomenon. But, as we will discuss in greater depth in Part I, low-level operations
details have always had strategic consequences for manufacturing firms. A relatively
recent reminder of this fact was the experience of Japan in the 1970s and 1980s. As
Chapter 4 describes, Japanese firms, particularly Toyota, were able to carry out a strategy
of low-cost, small-lot production only through intense attention to minute details on the
factory floor (e.g., die changing, statistical process control, material flow control) over
an extended time. The net result was an enormously effective competitive weapon that
permitted Toyota to rise from obscurity to a position as a worldwide automotive leader.
Today, the importance of operations to the health, and even viability, of manufacturing firms is greater than ever because of global competition in the following three
dimensions:
1. Cost. This is the traditional dimension of competition that has always been the
domain of operations management. Efficient utilization of labor, material, and
equipment is essential to keeping costs competitive. We should note, however,
that from the customer standpoint it is unit cost (total cost divided by total
volume) that matters, implying that both cost reduction and volume
enhancement are worthy OM objectives.
2. Quality. The 1980s brought widespread recognition in America that quality is a
key competitive weapon. Of course, external quality, that seen by the customer,
has always been a concern in manufacturing. The quality revolution of the
1980s served to focus attention on internal quality at each step in the
6
Chapter 0
Factory Physics?
manufacturing process, and its relationship to customer satisfaction. Facets of
operations management, such as statistical process control, human factors, and
material flow control, have loomed large in this context as components of total
quality management (TQM) strategies.
3. Speed. While cost and quality remain critical, the 1990s can be dubbed the
decade of speed. Rapid development of new products, coupled with quick
customer delivery, are pillars of the time-based competition (TBC) strategies
that have been adopted by leading firms in many industries. Bringing new
products to market swiftly requires both performance of development tasks in
parallel and the ability to efficiently ramp up production. Responsive delivery,
without inefficient excess inventory, requires short manufacturing cycle times,
reliable processes, and effective integration of disparate functions (e.g., sales
and manufacturing). These issues are central to operations management, and
they arise repeatedly throughout this book.
These three dimensions are broadly applicable to most manufacturing industries, but
their relative importance obviously varies from one firm to another. A manufacturer of
a commodity (baking soda, machine screws, resistors) depends critically on efficiency,
since low cost is a condition for survival. A manufacturer of premium goods (luxury automobiles, expensive watches, leatherbound books) relies on quality to retain its market.
A manufacturer of a high-technology product (computers, patent-protected pharmaceuticals, high-end consumer electronics) requires speed of introduction to be competitive and
to maximally exploit potential profit during the limited economic lifetime of the product.
Clearly, the management challenges in these varying environments are different. Since
operations are integral to cost, quality, and speed, however, operations management has
a key strategic role in each.
0.2.3 Method: Factory Physics
So far, we have determined that the focus of this book is manufacturing management, and
the scope is operations. The question now becomes, How can managers use an operations
viewpoint to identify a sensible combination of policies that are both effective now and
flexible enough to adapt to future needs?
In our opinion, some conventional approaches to manufacturing management fall
short:
1. Management by imitation is not the answer. Watching the competition can
provide a company with a valuable source of benchmarking and may help it to
avoid getting stuck in established modes of thinking. But imitation cannot
provide the impetus for a truly significant competitive edge. Bold new ideas
must come from within, not without.
2. Management by buzzword is not the answer. Manufacturing firms have become
inundated with a wave of “revolutions” in recent years. MRP, JIT, TQM, BPR,
TBC (and even a few without three-letter acronyms) have swept through the
manufacturing community, accompanied by soaring rhetoric and passionate
emotion, but with little concrete detail. As we will observe in Part I, these
movements have contained many valuable insights. However, they are very
dangerous as management systems because it is far too easy for managers to
become attached to catchy slogans and trendy buzzwords and lose sight of the
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DANCE ON STILTS AT THE GIRLS’ UNYAGO, NIUCHI
Newala, too, suffers from the distance of its water-supply—at least
the Newala of to-day does; there was once another Newala in a lovely
valley at the foot of the plateau. I visited it and found scarcely a trace
of houses, only a Christian cemetery, with the graves of several
missionaries and their converts, remaining as a monument of its
former glories. But the surroundings are wonderfully beautiful. A
thick grove of splendid mango-trees closes in the weather-worn
crosses and headstones; behind them, combining the useful and the
agreeable, is a whole plantation of lemon-trees covered with ripe
fruit; not the small African kind, but a much larger and also juicier
imported variety, which drops into the hands of the passing traveller,
without calling for any exertion on his part. Old Newala is now under
the jurisdiction of the native pastor, Daudi, at Chingulungulu, who,
as I am on very friendly terms with him, allows me, as a matter of
course, the use of this lemon-grove during my stay at Newala.
FEET MUTILATED BY THE RAVAGES OF THE “JIGGER”
(Sarcopsylla penetrans)
The water-supply of New Newala is in the bottom of the valley,
some 1,600 feet lower down. The way is not only long and fatiguing,
but the water, when we get it, is thoroughly bad. We are suffering not
only from this, but from the fact that the arrangements at Newala are
nothing short of luxurious. We have a separate kitchen—a hut built
against the boma palisade on the right of the baraza, the interior of
which is not visible from our usual position. Our two cooks were not
long in finding this out, and they consequently do—or rather neglect
to do—what they please. In any case they do not seem to be very
particular about the boiling of our drinking-water—at least I can
attribute to no other cause certain attacks of a dysenteric nature,
from which both Knudsen and I have suffered for some time. If a
man like Omari has to be left unwatched for a moment, he is capable
of anything. Besides this complaint, we are inconvenienced by the
state of our nails, which have become as hard as glass, and crack on
the slightest provocation, and I have the additional infliction of
pimples all over me. As if all this were not enough, we have also, for
the last week been waging war against the jigger, who has found his
Eldorado in the hot sand of the Makonde plateau. Our men are seen
all day long—whenever their chronic colds and the dysentery likewise
raging among them permit—occupied in removing this scourge of
Africa from their feet and trying to prevent the disastrous
consequences of its presence. It is quite common to see natives of
this place with one or two toes missing; many have lost all their toes,
or even the whole front part of the foot, so that a well-formed leg
ends in a shapeless stump. These ravages are caused by the female of
Sarcopsylla penetrans, which bores its way under the skin and there
develops an egg-sac the size of a pea. In all books on the subject, it is
stated that one’s attention is called to the presence of this parasite by
an intolerable itching. This agrees very well with my experience, so
far as the softer parts of the sole, the spaces between and under the
toes, and the side of the foot are concerned, but if the creature
penetrates through the harder parts of the heel or ball of the foot, it
may escape even the most careful search till it has reached maturity.
Then there is no time to be lost, if the horrible ulceration, of which
we see cases by the dozen every day, is to be prevented. It is much
easier, by the way, to discover the insect on the white skin of a
European than on that of a native, on which the dark speck scarcely
shows. The four or five jiggers which, in spite of the fact that I
constantly wore high laced boots, chose my feet to settle in, were
taken out for me by the all-accomplished Knudsen, after which I
thought it advisable to wash out the cavities with corrosive
sublimate. The natives have a different sort of disinfectant—they fill
the hole with scraped roots. In a tiny Makua village on the slope of
the plateau south of Newala, we saw an old woman who had filled all
the spaces under her toe-nails with powdered roots by way of
prophylactic treatment. What will be the result, if any, who can say?
The rest of the many trifling ills which trouble our existence are
really more comic than serious. In the absence of anything else to
smoke, Knudsen and I at last opened a box of cigars procured from
the Indian store-keeper at Lindi, and tried them, with the most
distressing results. Whether they contain opium or some other
narcotic, neither of us can say, but after the tenth puff we were both
“off,” three-quarters stupefied and unspeakably wretched. Slowly we
recovered—and what happened next? Half-an-hour later we were
once more smoking these poisonous concoctions—so insatiable is the
craving for tobacco in the tropics.
Even my present attacks of fever scarcely deserve to be taken
seriously. I have had no less than three here at Newala, all of which
have run their course in an incredibly short time. In the early
afternoon, I am busy with my old natives, asking questions and
making notes. The strong midday coffee has stimulated my spirits to
an extraordinary degree, the brain is active and vigorous, and work
progresses rapidly, while a pleasant warmth pervades the whole
body. Suddenly this gives place to a violent chill, forcing me to put on
my overcoat, though it is only half-past three and the afternoon sun
is at its hottest. Now the brain no longer works with such acuteness
and logical precision; more especially does it fail me in trying to
establish the syntax of the difficult Makua language on which I have
ventured, as if I had not enough to do without it. Under the
circumstances it seems advisable to take my temperature, and I do
so, to save trouble, without leaving my seat, and while going on with
my work. On examination, I find it to be 101·48°. My tutors are
abruptly dismissed and my bed set up in the baraza; a few minutes
later I am in it and treating myself internally with hot water and
lemon-juice.
Three hours later, the thermometer marks nearly 104°, and I make
them carry me back into the tent, bed and all, as I am now perspiring
heavily, and exposure to the cold wind just beginning to blow might
mean a fatal chill. I lie still for a little while, and then find, to my
great relief, that the temperature is not rising, but rather falling. This
is about 7.30 p.m. At 8 p.m. I find, to my unbounded astonishment,
that it has fallen below 98·6°, and I feel perfectly well. I read for an
hour or two, and could very well enjoy a smoke, if I had the
wherewithal—Indian cigars being out of the question.
Having no medical training, I am at a loss to account for this state
of things. It is impossible that these transitory attacks of high fever
should be malarial; it seems more probable that they are due to a
kind of sunstroke. On consulting my note-book, I become more and
more inclined to think this is the case, for these attacks regularly
follow extreme fatigue and long exposure to strong sunshine. They at
least have the advantage of being only short interruptions to my
work, as on the following morning I am always quite fresh and fit.
My treasure of a cook is suffering from an enormous hydrocele which
makes it difficult for him to get up, and Moritz is obliged to keep in
the dark on account of his inflamed eyes. Knudsen’s cook, a raw boy
from somewhere in the bush, knows still less of cooking than Omari;
consequently Nils Knudsen himself has been promoted to the vacant
post. Finding that we had come to the end of our supplies, he began
by sending to Chingulungulu for the four sucking-pigs which we had
bought from Matola and temporarily left in his charge; and when
they came up, neatly packed in a large crate, he callously slaughtered
the biggest of them. The first joint we were thoughtless enough to
entrust for roasting to Knudsen’s mshenzi cook, and it was
consequently uneatable; but we made the rest of the animal into a
jelly which we ate with great relish after weeks of underfeeding,
consuming incredible helpings of it at both midday and evening
meals. The only drawback is a certain want of variety in the tinned
vegetables. Dr. Jäger, to whom the Geographical Commission
entrusted the provisioning of the expeditions—mine as well as his
own—because he had more time on his hands than the rest of us,
seems to have laid in a huge stock of Teltow turnips,[46] an article of
food which is all very well for occasional use, but which quickly palls
when set before one every day; and we seem to have no other tins
left. There is no help for it—we must put up with the turnips; but I
am certain that, once I am home again, I shall not touch them for ten
years to come.
Amid all these minor evils, which, after all, go to make up the
genuine flavour of Africa, there is at least one cheering touch:
Knudsen has, with the dexterity of a skilled mechanic, repaired my 9
× 12 cm. camera, at least so far that I can use it with a little care.
How, in the absence of finger-nails, he was able to accomplish such a
ticklish piece of work, having no tool but a clumsy screw-driver for
taking to pieces and putting together again the complicated
mechanism of the instantaneous shutter, is still a mystery to me; but
he did it successfully. The loss of his finger-nails shows him in a light
contrasting curiously enough with the intelligence evinced by the
above operation; though, after all, it is scarcely surprising after his
ten years’ residence in the bush. One day, at Lindi, he had occasion
to wash a dog, which must have been in need of very thorough
cleansing, for the bottle handed to our friend for the purpose had an
extremely strong smell. Having performed his task in the most
conscientious manner, he perceived with some surprise that the dog
did not appear much the better for it, and was further surprised by
finding his own nails ulcerating away in the course of the next few
days. “How was I to know that carbolic acid has to be diluted?” he
mutters indignantly, from time to time, with a troubled gaze at his
mutilated finger-tips.
Since we came to Newala we have been making excursions in all
directions through the surrounding country, in accordance with old
habit, and also because the akida Sefu did not get together the tribal
elders from whom I wanted information so speedily as he had
promised. There is, however, no harm done, as, even if seen only
from the outside, the country and people are interesting enough.
The Makonde plateau is like a large rectangular table rounded off
at the corners. Measured from the Indian Ocean to Newala, it is
about seventy-five miles long, and between the Rovuma and the
Lukuledi it averages fifty miles in breadth, so that its superficial area
is about two-thirds of that of the kingdom of Saxony. The surface,
however, is not level, but uniformly inclined from its south-western
edge to the ocean. From the upper edge, on which Newala lies, the
eye ranges for many miles east and north-east, without encountering
any obstacle, over the Makonde bush. It is a green sea, from which
here and there thick clouds of smoke rise, to show that it, too, is
inhabited by men who carry on their tillage like so many other
primitive peoples, by cutting down and burning the bush, and
manuring with the ashes. Even in the radiant light of a tropical day
such a fire is a grand sight.
Much less effective is the impression produced just now by the
great western plain as seen from the edge of the plateau. As often as
time permits, I stroll along this edge, sometimes in one direction,
sometimes in another, in the hope of finding the air clear enough to
let me enjoy the view; but I have always been disappointed.
Wherever one looks, clouds of smoke rise from the burning bush,
and the air is full of smoke and vapour. It is a pity, for under more
favourable circumstances the panorama of the whole country up to
the distant Majeje hills must be truly magnificent. It is of little use
taking photographs now, and an outline sketch gives a very poor idea
of the scenery. In one of these excursions I went out of my way to
make a personal attempt on the Makonde bush. The present edge of
the plateau is the result of a far-reaching process of destruction
through erosion and denudation. The Makonde strata are
everywhere cut into by ravines, which, though short, are hundreds of
yards in depth. In consequence of the loose stratification of these
beds, not only are the walls of these ravines nearly vertical, but their
upper end is closed by an equally steep escarpment, so that the
western edge of the Makonde plateau is hemmed in by a series of
deep, basin-like valleys. In order to get from one side of such a ravine
to the other, I cut my way through the bush with a dozen of my men.
It was a very open part, with more grass than scrub, but even so the
short stretch of less than two hundred yards was very hard work; at
the end of it the men’s calicoes were in rags and they themselves
bleeding from hundreds of scratches, while even our strong khaki
suits had not escaped scatheless.
NATIVE PATH THROUGH THE MAKONDE BUSH, NEAR
MAHUTA
I see increasing reason to believe that the view formed some time
back as to the origin of the Makonde bush is the correct one. I have
no doubt that it is not a natural product, but the result of human
occupation. Those parts of the high country where man—as a very
slight amount of practice enables the eye to perceive at once—has not
yet penetrated with axe and hoe, are still occupied by a splendid
timber forest quite able to sustain a comparison with our mixed
forests in Germany. But wherever man has once built his hut or tilled
his field, this horrible bush springs up. Every phase of this process
may be seen in the course of a couple of hours’ walk along the main
road. From the bush to right or left, one hears the sound of the axe—
not from one spot only, but from several directions at once. A few
steps further on, we can see what is taking place. The brush has been
cut down and piled up in heaps to the height of a yard or more,
between which the trunks of the large trees stand up like the last
pillars of a magnificent ruined building. These, too, present a
melancholy spectacle: the destructive Makonde have ringed them—
cut a broad strip of bark all round to ensure their dying off—and also
piled up pyramids of brush round them. Father and son, mother and
son-in-law, are chopping away perseveringly in the background—too
busy, almost, to look round at the white stranger, who usually excites
so much interest. If you pass by the same place a week later, the piles
of brushwood have disappeared and a thick layer of ashes has taken
the place of the green forest. The large trees stretch their
smouldering trunks and branches in dumb accusation to heaven—if
they have not already fallen and been more or less reduced to ashes,
perhaps only showing as a white stripe on the dark ground.
This work of destruction is carried out by the Makonde alike on the
virgin forest and on the bush which has sprung up on sites already
cultivated and deserted. In the second case they are saved the trouble
of burning the large trees, these being entirely absent in the
secondary bush.
After burning this piece of forest ground and loosening it with the
hoe, the native sows his corn and plants his vegetables. All over the
country, he goes in for bed-culture, which requires, and, in fact,
receives, the most careful attention. Weeds are nowhere tolerated in
the south of German East Africa. The crops may fail on the plains,
where droughts are frequent, but never on the plateau with its
abundant rains and heavy dews. Its fortunate inhabitants even have
the satisfaction of seeing the proud Wayao and Wamakua working
for them as labourers, driven by hunger to serve where they were
accustomed to rule.
But the light, sandy soil is soon exhausted, and would yield no
harvest the second year if cultivated twice running. This fact has
been familiar to the native for ages; consequently he provides in
time, and, while his crop is growing, prepares the next plot with axe
and firebrand. Next year he plants this with his various crops and
lets the first piece lie fallow. For a short time it remains waste and
desolate; then nature steps in to repair the destruction wrought by
man; a thousand new growths spring out of the exhausted soil, and
even the old stumps put forth fresh shoots. Next year the new growth
is up to one’s knees, and in a few years more it is that terrible,
impenetrable bush, which maintains its position till the black
occupier of the land has made the round of all the available sites and
come back to his starting point.
The Makonde are, body and soul, so to speak, one with this bush.
According to my Yao informants, indeed, their name means nothing
else but “bush people.” Their own tradition says that they have been
settled up here for a very long time, but to my surprise they laid great
stress on an original immigration. Their old homes were in the
south-east, near Mikindani and the mouth of the Rovuma, whence
their peaceful forefathers were driven by the continual raids of the
Sakalavas from Madagascar and the warlike Shirazis[47] of the coast,
to take refuge on the almost inaccessible plateau. I have studied
African ethnology for twenty years, but the fact that changes of
population in this apparently quiet and peaceable corner of the earth
could have been occasioned by outside enterprises taking place on
the high seas, was completely new to me. It is, no doubt, however,
correct.
The charming tribal legend of the Makonde—besides informing us
of other interesting matters—explains why they have to live in the
thickest of the bush and a long way from the edge of the plateau,
instead of making their permanent homes beside the purling brooks
and springs of the low country.
“The place where the tribe originated is Mahuta, on the southern
side of the plateau towards the Rovuma, where of old time there was
nothing but thick bush. Out of this bush came a man who never
washed himself or shaved his head, and who ate and drank but little.
He went out and made a human figure from the wood of a tree
growing in the open country, which he took home to his abode in the
bush and there set it upright. In the night this image came to life and
was a woman. The man and woman went down together to the
Rovuma to wash themselves. Here the woman gave birth to a stillborn child. They left that place and passed over the high land into the
valley of the Mbemkuru, where the woman had another child, which
was also born dead. Then they returned to the high bush country of
Mahuta, where the third child was born, which lived and grew up. In
course of time, the couple had many more children, and called
themselves Wamatanda. These were the ancestral stock of the
Makonde, also called Wamakonde,[48] i.e., aborigines. Their
forefather, the man from the bush, gave his children the command to
bury their dead upright, in memory of the mother of their race who
was cut out of wood and awoke to life when standing upright. He also
warned them against settling in the valleys and near large streams,
for sickness and death dwelt there. They were to make it a rule to
have their huts at least an hour’s walk from the nearest wateringplace; then their children would thrive and escape illness.”
The explanation of the name Makonde given by my informants is
somewhat different from that contained in the above legend, which I
extract from a little book (small, but packed with information), by
Pater Adams, entitled Lindi und sein Hinterland. Otherwise, my
results agree exactly with the statements of the legend. Washing?
Hapana—there is no such thing. Why should they do so? As it is, the
supply of water scarcely suffices for cooking and drinking; other
people do not wash, so why should the Makonde distinguish himself
by such needless eccentricity? As for shaving the head, the short,
woolly crop scarcely needs it,[49] so the second ancestral precept is
likewise easy enough to follow. Beyond this, however, there is
nothing ridiculous in the ancestor’s advice. I have obtained from
various local artists a fairly large number of figures carved in wood,
ranging from fifteen to twenty-three inches in height, and
representing women belonging to the great group of the Mavia,
Makonde, and Matambwe tribes. The carving is remarkably well
done and renders the female type with great accuracy, especially the
keloid ornamentation, to be described later on. As to the object and
meaning of their works the sculptors either could or (more probably)
would tell me nothing, and I was forced to content myself with the
scanty information vouchsafed by one man, who said that the figures
were merely intended to represent the nembo—the artificial
deformations of pelele, ear-discs, and keloids. The legend recorded
by Pater Adams places these figures in a new light. They must surely
be more than mere dolls; and we may even venture to assume that
they are—though the majority of present-day Makonde are probably
unaware of the fact—representations of the tribal ancestress.
The references in the legend to the descent from Mahuta to the
Rovuma, and to a journey across the highlands into the Mbekuru
valley, undoubtedly indicate the previous history of the tribe, the
travels of the ancestral pair typifying the migrations of their
descendants. The descent to the neighbouring Rovuma valley, with
its extraordinary fertility and great abundance of game, is intelligible
at a glance—but the crossing of the Lukuledi depression, the ascent
to the Rondo Plateau and the descent to the Mbemkuru, also lie
within the bounds of probability, for all these districts have exactly
the same character as the extreme south. Now, however, comes a
point of especial interest for our bacteriological age. The primitive
Makonde did not enjoy their lives in the marshy river-valleys.
Disease raged among them, and many died. It was only after they
had returned to their original home near Mahuta, that the health
conditions of these people improved. We are very apt to think of the
African as a stupid person whose ignorance of nature is only equalled
by his fear of it, and who looks on all mishaps as caused by evil
spirits and malignant natural powers. It is much more correct to
assume in this case that the people very early learnt to distinguish
districts infested with malaria from those where it is absent.
This knowledge is crystallized in the
ancestral warning against settling in the
valleys and near the great waters, the
dwelling-places of disease and death. At the
same time, for security against the hostile
Mavia south of the Rovuma, it was enacted
that every settlement must be not less than a
certain distance from the southern edge of the
plateau. Such in fact is their mode of life at the
present day. It is not such a bad one, and
certainly they are both safer and more
comfortable than the Makua, the recent
intruders from the south, who have made USUAL METHOD OF
good their footing on the western edge of the CLOSING HUT-DOOR
plateau, extending over a fairly wide belt of
country. Neither Makua nor Makonde show in their dwellings
anything of the size and comeliness of the Yao houses in the plain,
especially at Masasi, Chingulungulu and Zuza’s. Jumbe Chauro, a
Makonde hamlet not far from Newala, on the road to Mahuta, is the
most important settlement of the tribe I have yet seen, and has fairly
spacious huts. But how slovenly is their construction compared with
the palatial residences of the elephant-hunters living in the plain.
The roofs are still more untidy than in the general run of huts during
the dry season, the walls show here and there the scanty beginnings
or the lamentable remains of the mud plastering, and the interior is a
veritable dog-kennel; dirt, dust and disorder everywhere. A few huts
only show any attempt at division into rooms, and this consists
merely of very roughly-made bamboo partitions. In one point alone
have I noticed any indication of progress—in the method of fastening
the door. Houses all over the south are secured in a simple but
ingenious manner. The door consists of a set of stout pieces of wood
or bamboo, tied with bark-string to two cross-pieces, and moving in
two grooves round one of the door-posts, so as to open inwards. If
the owner wishes to leave home, he takes two logs as thick as a man’s
upper arm and about a yard long. One of these is placed obliquely
against the middle of the door from the inside, so as to form an angle
of from 60° to 75° with the ground. He then places the second piece
horizontally across the first, pressing it downward with all his might.
It is kept in place by two strong posts planted in the ground a few
inches inside the door. This fastening is absolutely safe, but of course
cannot be applied to both doors at once, otherwise how could the
owner leave or enter his house? I have not yet succeeded in finding
out how the back door is fastened.
MAKONDE LOCK AND KEY AT JUMBE CHAURO
This is the general way of closing a house. The Makonde at Jumbe
Chauro, however, have a much more complicated, solid and original
one. Here, too, the door is as already described, except that there is
only one post on the inside, standing by itself about six inches from
one side of the doorway. Opposite this post is a hole in the wall just
large enough to admit a man’s arm. The door is closed inside by a
large wooden bolt passing through a hole in this post and pressing
with its free end against the door. The other end has three holes into
which fit three pegs running in vertical grooves inside the post. The
door is opened with a wooden key about a foot long, somewhat
curved and sloped off at the butt; the other end has three pegs
corresponding to the holes, in the bolt, so that, when it is thrust
through the hole in the wall and inserted into the rectangular
opening in the post, the pegs can be lifted and the bolt drawn out.[50]
MODE OF INSERTING THE KEY
With no small pride first one householder and then a second
showed me on the spot the action of this greatest invention of the
Makonde Highlands. To both with an admiring exclamation of
“Vizuri sana!” (“Very fine!”). I expressed the wish to take back these
marvels with me to Ulaya, to show the Wazungu what clever fellows
the Makonde are. Scarcely five minutes after my return to camp at
Newala, the two men came up sweating under the weight of two
heavy logs which they laid down at my feet, handing over at the same
time the keys of the fallen fortress. Arguing, logically enough, that if
the key was wanted, the lock would be wanted with it, they had taken
their axes and chopped down the posts—as it never occurred to them
to dig them out of the ground and so bring them intact. Thus I have
two badly damaged specimens, and the owners, instead of praise,
come in for a blowing-up.
The Makua huts in the environs of Newala are especially
miserable; their more than slovenly construction reminds one of the
temporary erections of the Makua at Hatia’s, though the people here
have not been concerned in a war. It must therefore be due to
congenital idleness, or else to the absence of a powerful chief. Even
the baraza at Mlipa’s, a short hour’s walk south-east of Newala,
shares in this general neglect. While public buildings in this country
are usually looked after more or less carefully, this is in evident
danger of being blown over by the first strong easterly gale. The only
attractive object in this whole district is the grave of the late chief
Mlipa. I visited it in the morning, while the sun was still trying with
partial success to break through the rolling mists, and the circular
grove of tall euphorbias, which, with a broken pot, is all that marks
the old king’s resting-place, impressed one with a touch of pathos.
Even my very materially-minded carriers seemed to feel something
of the sort, for instead of their usual ribald songs, they chanted
solemnly, as we marched on through the dense green of the Makonde
bush:—
“We shall arrive with the great master; we stand in a row and have
no fear about getting our food and our money from the Serkali (the
Government). We are not afraid; we are going along with the great
master, the lion; we are going down to the coast and back.”
With regard to the characteristic features of the various tribes here
on the western edge of the plateau, I can arrive at no other
conclusion than the one already come to in the plain, viz., that it is
impossible for anyone but a trained anthropologist to assign any
given individual at once to his proper tribe. In fact, I think that even
an anthropological specialist, after the most careful examination,
might find it a difficult task to decide. The whole congeries of peoples
collected in the region bounded on the west by the great Central
African rift, Tanganyika and Nyasa, and on the east by the Indian
Ocean, are closely related to each other—some of their languages are
only distinguished from one another as dialects of the same speech,
and no doubt all the tribes present the same shape of skull and
structure of skeleton. Thus, surely, there can be no very striking
differences in outward appearance.
Even did such exist, I should have no time
to concern myself with them, for day after day,
I have to see or hear, as the case may be—in
any case to grasp and record—an
extraordinary number of ethnographic
phenomena. I am almost disposed to think it
fortunate that some departments of inquiry, at
least, are barred by external circumstances.
Chief among these is the subject of ironworking. We are apt to think of Africa as a
country where iron ore is everywhere, so to
speak, to be picked up by the roadside, and
where it would be quite surprising if the
inhabitants had not learnt to smelt the
material ready to their hand. In fact, the
knowledge of this art ranges all over the
continent, from the Kabyles in the north to the
Kafirs in the south. Here between the Rovuma
and the Lukuledi the conditions are not so
favourable. According to the statements of the
Makonde, neither ironstone nor any other
form of iron ore is known to them. They have
not therefore advanced to the art of smelting
the metal, but have hitherto bought all their
THE ANCESTRESS OF
iron implements from neighbouring tribes.
THE MAKONDE
Even in the plain the inhabitants are not much
better off. Only one man now living is said to
understand the art of smelting iron. This old fundi lives close to
Huwe, that isolated, steep-sided block of granite which rises out of
the green solitude between Masasi and Chingulungulu, and whose
jagged and splintered top meets the traveller’s eye everywhere. While
still at Masasi I wished to see this man at work, but was told that,
frightened by the rising, he had retired across the Rovuma, though
he would soon return. All subsequent inquiries as to whether the
fundi had come back met with the genuine African answer, “Bado”
(“Not yet”).
BRAZIER
Some consolation was afforded me by a brassfounder, whom I
came across in the bush near Akundonde’s. This man is the favourite
of women, and therefore no doubt of the gods; he welds the glittering
brass rods purchased at the coast into those massive, heavy rings
which, on the wrists and ankles of the local fair ones, continually give
me fresh food for admiration. Like every decent master-craftsman he
had all his tools with him, consisting of a pair of bellows, three
crucibles and a hammer—nothing more, apparently. He was quite
willing to show his skill, and in a twinkling had fixed his bellows on
the ground. They are simply two goat-skins, taken off whole, the four
legs being closed by knots, while the upper opening, intended to
admit the air, is kept stretched by two pieces of wood. At the lower
end of the skin a smaller opening is left into which a wooden tube is
stuck. The fundi has quickly borrowed a heap of wood-embers from
the nearest hut; he then fixes the free ends of the two tubes into an
earthen pipe, and clamps them to the ground by means of a bent
piece of wood. Now he fills one of his small clay crucibles, the dross
on which shows that they have been long in use, with the yellow
material, places it in the midst of the embers, which, at present are
only faintly glimmering, and begins his work. In quick alternation
the smith’s two hands move up and down with the open ends of the
bellows; as he raises his hand he holds the slit wide open, so as to let
the air enter the skin bag unhindered. In pressing it down he closes
the bag, and the air puffs through the bamboo tube and clay pipe into
the fire, which quickly burns up. The smith, however, does not keep
on with this work, but beckons to another man, who relieves him at
the bellows, while he takes some more tools out of a large skin pouch
carried on his back. I look on in wonder as, with a smooth round
stick about the thickness of a finger, he bores a few vertical holes into
the clean sand of the soil. This should not be difficult, yet the man
seems to be taking great pains over it. Then he fastens down to the
ground, with a couple of wooden clamps, a neat little trough made by
splitting a joint of bamboo in half, so that the ends are closed by the
two knots. At last the yellow metal has attained the right consistency,
and the fundi lifts the crucible from the fire by means of two sticks
split at the end to serve as tongs. A short swift turn to the left—a
tilting of the crucible—and the molten brass, hissing and giving forth
clouds of smoke, flows first into the bamboo mould and then into the
holes in the ground.
The technique of this backwoods craftsman may not be very far
advanced, but it cannot be denied that he knows how to obtain an
adequate result by the simplest means. The ladies of highest rank in
this country—that is to say, those who can afford it, wear two kinds
of these massive brass rings, one cylindrical, the other semicircular
in section. The latter are cast in the most ingenious way in the
bamboo mould, the former in the circular hole in the sand. It is quite
a simple matter for the fundi to fit these bars to the limbs of his fair
customers; with a few light strokes of his hammer he bends the
pliable brass round arm or ankle without further inconvenience to
the wearer.
SHAPING THE POT
SMOOTHING WITH MAIZE-COB
CUTTING THE EDGE
FINISHING THE BOTTOM
LAST SMOOTHING BEFORE
BURNING
FIRING THE BRUSH-PILE
LIGHTING THE FARTHER SIDE OF
THE PILE
TURNING THE RED-HOT VESSEL
NYASA WOMAN MAKING POTS AT MASASI
Pottery is an art which must always and everywhere excite the
interest of the student, just because it is so intimately connected with
the development of human culture, and because its relics are one of
the principal factors in the reconstruction of our own condition in
prehistoric times. I shall always remember with pleasure the two or
three afternoons at Masasi when Salim Matola’s mother, a slightlybuilt, graceful, pleasant-looking woman, explained to me with
touching patience, by means of concrete illustrations, the ceramic art
of her people. The only implements for this primitive process were a
lump of clay in her left hand, and in the right a calabash containing
the following valuables: the fragment of a maize-cob stripped of all
its grains, a smooth, oval pebble, about the size of a pigeon’s egg, a
few chips of gourd-shell, a bamboo splinter about the length of one’s
hand, a small shell, and a bunch of some herb resembling spinach.
Nothing more. The woman scraped with the
shell a round, shallow hole in the soft, fine
sand of the soil, and, when an active young
girl had filled the calabash with water for her,
she began to knead the clay. As if by magic it
gradually assumed the shape of a rough but
already well-shaped vessel, which only wanted
a little touching up with the instruments
before mentioned. I looked out with the
closest attention for any indication of the use
MAKUA WOMAN
MAKING A POT.
of the potter’s wheel, in however rudimentary
SHOWS THE
a form, but no—hapana (there is none). The
BEGINNINGS OF THE embryo pot stood firmly in its little
POTTER’S WHEEL
depression, and the woman walked round it in
a stooping posture, whether she was removing
small stones or similar foreign bodies with the maize-cob, smoothing
the inner or outer surface with the splinter of bamboo, or later, after
letting it dry for a day, pricking in the ornamentation with a pointed
bit of gourd-shell, or working out the bottom, or cutting the edge
with a sharp bamboo knife, or giving the last touches to the finished
vessel. This occupation of the women is infinitely toilsome, but it is
without doubt an accurate reproduction of the process in use among
our ancestors of the Neolithic and Bronze ages.
There is no doubt that the invention of pottery, an item in human
progress whose importance cannot be over-estimated, is due to
women. Rough, coarse and unfeeling, the men of the horde range
over the countryside. When the united cunning of the hunters has
succeeded in killing the game; not one of them thinks of carrying
home the spoil. A bright fire, kindled by a vigorous wielding of the
drill, is crackling beside them; the animal has been cleaned and cut
up secundum artem, and, after a slight singeing, will soon disappear
under their sharp teeth; no one all this time giving a single thought
to wife or child.
To what shifts, on the other hand, the primitive wife, and still more
the primitive mother, was put! Not even prehistoric stomachs could
endure an unvarying diet of raw food. Something or other suggested
the beneficial effect of hot water on the majority of approved but
indigestible dishes. Perhaps a neighbour had tried holding the hard
roots or tubers over the fire in a calabash filled with water—or maybe
an ostrich-egg-shell, or a hastily improvised vessel of bark. They
became much softer and more palatable than they had previously
been; but, unfortunately, the vessel could not stand the fire and got
charred on the outside. That can be remedied, thought our
ancestress, and plastered a layer of wet clay round a similar vessel.
This is an improvement; the cooking utensil remains uninjured, but
the heat of the fire has shrunk it, so that it is loose in its shell. The
next step is to detach it, so, with a firm grip and a jerk, shell and
kernel are separated, and pottery is invented. Perhaps, however, the
discovery which led to an intelligent use of the burnt-clay shell, was
made in a slightly different way. Ostrich-eggs and calabashes are not
to be found in every part of the world, but everywhere mankind has
arrived at the art of making baskets out of pliant materials, such as
bark, bast, strips of palm-leaf, supple twigs, etc. Our inventor has no
water-tight vessel provided by nature. “Never mind, let us line the
basket with clay.” This answers the purpose, but alas! the basket gets
burnt over the blazing fire, the woman watches the process of
cooking with increasing uneasiness, fearing a leak, but no leak
appears. The food, done to a turn, is eaten with peculiar relish; and
the cooking-vessel is examined, half in curiosity, half in satisfaction
at the result. The plastic clay is now hard as stone, and at the same
time looks exceedingly well, for the neat plaiting of the burnt basket
is traced all over it in a pretty pattern. Thus, simultaneously with
pottery, its ornamentation was invented.
Primitive woman has another claim to respect. It was the man,
roving abroad, who invented the art of producing fire at will, but the
woman, unable to imitate him in this, has been a Vestal from the
earliest times. Nothing gives so much trouble as the keeping alight of
the smouldering brand, and, above all, when all the men are absent
from the camp. Heavy rain-clouds gather, already the first large
drops are falling, the first gusts of the storm rage over the plain. The
little flame, a greater anxiety to the woman than her own children,
flickers unsteadily in the blast. What is to be done? A sudden thought
occurs to her, and in an instant she has constructed a primitive hut
out of strips of bark, to protect the flame against rain and wind.
This, or something very like it, was the way in which the principle
of the house was discovered; and even the most hardened misogynist
cannot fairly refuse a woman the credit of it. The protection of the
hearth-fire from the weather is the germ from which the human
dwelling was evolved. Men had little, if any share, in this forward
step, and that only at a late stage. Even at the present day, the
plastering of the housewall with clay and the manufacture of pottery
are exclusively the women’s business. These are two very significant
survivals. Our European kitchen-garden, too, is originally a woman’s
invention, and the hoe, the primitive instrument of agriculture, is,
characteristically enough, still used in this department. But the
noblest achievement which we owe to the other sex is unquestionably
the art of cookery. Roasting alone—the oldest process—is one for
which men took the hint (a very obvious one) from nature. It must
have been suggested by the scorched carcase of some animal
overtaken by the destructive forest-fires. But boiling—the process of
improving organic substances by the help of water heated to boilingpoint—is a much later discovery. It is so recent that it has not even
yet penetrated to all parts of the world. The Polynesians understand
how to steam food, that is, to cook it, neatly wrapped in leaves, in a
hole in the earth between hot stones, the air being excluded, and
(sometimes) a few drops of water sprinkled on the stones; but they
do not understand boiling.
To come back from this digression, we find that the slender Nyasa
woman has, after once more carefully examining the finished pot,
put it aside in the shade to dry. On the following day she sends me
word by her son, Salim Matola, who is always on hand, that she is
going to do the burning, and, on coming out of my house, I find her
already hard at work. She has spread on the ground a layer of very
dry sticks, about as thick as one’s thumb, has laid the pot (now of a
yellowish-grey colour) on them, and is piling brushwood round it.
My faithful Pesa mbili, the mnyampara, who has been standing by,
most obligingly, with a lighted stick, now hands it to her. Both of
them, blowing steadily, light the pile on the lee side, and, when the
flame begins to catch, on the weather side also. Soon the whole is in a
blaze, but the dry fuel is quickly consumed and the fire dies down, so
that we see the red-hot vessel rising from the ashes. The woman
turns it continually with a long stick, sometimes one way and
sometimes another, so that it may be evenly heated all over. In
twenty minutes she rolls it out of the ash-heap, takes up the bundle
of spinach, which has been lying for two days in a jar of water, and
sprinkles the red-hot clay with it. The places where the drops fall are
marked by black spots on the uniform reddish-brown surface. With a
sigh of relief, and with visible satisfaction, the woman rises to an
erect position; she is standing just in a line between me and the fire,
from which a cloud of smoke is just rising: I press the ball of my
camera, the shutter clicks—the apotheosis is achieved! Like a
priestess, representative of her inventive sex, the graceful woman
stands: at her feet the hearth-fire she has given us beside her the
invention she has devised for us, in the background the home she has
built for us.
At Newala, also, I have had the manufacture of pottery carried on
in my presence. Technically the process is better than that already
described, for here we find the beginnings of the potter’s wheel,
which does not seem to exist in the plains; at least I have seen
nothing of the sort. The artist, a frightfully stupid Makua woman, did
not make a depression in the ground to receive the pot she was about
to shape, but used instead a large potsherd. Otherwise, she went to
work in much the same way as Salim’s mother, except that she saved
herself the trouble of walking round and round her work by squatting
at her ease and letting the pot and potsherd rotate round her; this is
surely the first step towards a machine. But it does not follow that
the pot was improved by the process. It is true that it was beautifully
rounded and presented a very creditable appearance when finished,
but the numerous large and small vessels which I have seen, and, in
part, collected, in the “less advanced” districts, are no less so. We
moderns imagine that instruments of precision are necessary to
produce excellent results. Go to the prehistoric collections of our
museums and look at the pots, urns and bowls of our ancestors in the
dim ages of the past, and you will at once perceive your error.
MAKING LONGITUDINAL CUT IN
BARK
DRAWING THE BARK OFF THE LOG
REMOVING THE OUTER BARK
BEATING THE BARK
WORKING THE BARK-CLOTH AFTER BEATING, TO MAKE IT
SOFT
MANUFACTURE OF BARK-CLOTH AT NEWALA
To-day, nearly the whole population of German East Africa is
clothed in imported calico. This was not always the case; even now in
some parts of the north dressed skins are still the prevailing wear,
and in the north-western districts—east and north of Lake
Tanganyika—lies a zone where bark-cloth has not yet been
superseded. Probably not many generations have passed since such
bark fabrics and kilts of skins were the only clothing even in the
south. Even to-day, large quantities of this bright-red or drab
material are still to be found; but if we wish to see it, we must look in
the granaries and on the drying stages inside the native huts, where
it serves less ambitious uses as wrappings for those seeds and fruits
which require to be packed with special care. The salt produced at
Masasi, too, is packed for transport to a distance in large sheets of
bark-cloth. Wherever I found it in any degree possible, I studied the
process of making this cloth. The native requisitioned for the
purpose arrived, carrying a log between two and three yards long and
as thick as his thigh, and nothing else except a curiously-shaped
mallet and the usual long, sharp and pointed knife which all men and
boys wear in a belt at their backs without a sheath—horribile dictu!
[51]
Silently he squats down before me, and with two rapid cuts has
drawn a couple of circles round the log some two yards apart, and
slits the bark lengthwise between them with the point of his knife.
With evident care, he then scrapes off the outer rind all round the
log, so that in a quarter of an hour the inner red layer of the bark
shows up brightly-coloured between the two untouched ends. With
some trouble and much caution, he now loosens the bark at one end,
and opens the cylinder. He then stands up, takes hold of the free
edge with both hands, and turning it inside out, slowly but steadily
pulls it off in one piece. Now comes the troublesome work of
scraping all superfluous particles of outer bark from the outside of
the long, narrow piece of material, while the inner side is carefully
scrutinised for defective spots. At last it is ready for beating. Having
signalled to a friend, who immediately places a bowl of water beside
him, the artificer damps his sheet of bark all over, seizes his mallet,
lays one end of the stuff on the smoothest spot of the log, and
hammers away slowly but continuously. “Very simple!” I think to
myself. “Why, I could do that, too!”—but I am forced to change my
opinions a little later on; for the beating is quite an art, if the fabric is
not to be beaten to pieces. To prevent the breaking of the fibres, the
stuff is several times folded across, so as to interpose several
thicknesses between the mallet and the block. At last the required
state is reached, and the fundi seizes the sheet, still folded, by both
ends, and wrings it out, or calls an assistant to take one end while he
holds the other. The cloth produced in this way is not nearly so fine
and uniform in texture as the famous Uganda bark-cloth, but it is
quite soft, and, above all, cheap.
Now, too, I examine the mallet. My craftsman has been using the
simpler but better form of this implement, a conical block of some
hard wood, its base—the striking surface—being scored across and
across with more or less deeply-cut grooves, and the handle stuck
into a hole in the middle. The other and earlier form of mallet is
shaped in the same way, but the head is fastened by an ingenious
network of bark strips into the split bamboo serving as a handle. The
observation so often made, that ancient customs persist longest in
connection with religious ceremonies and in the life of children, here
finds confirmation. As we shall soon see, bark-cloth is still worn
during the unyago,[52] having been prepared with special solemn
ceremonies; and many a mother, if she has no other garment handy,
will still put her little one into a kilt of bark-cloth, which, after all,
looks better, besides being more in keeping with its African
surroundings, than the ridiculous bit of print from Ulaya.
MAKUA WOMEN