Chapter 1
Methods, Standards, and Work Design: Introduction
1.1 PRODUCTIVITY IMPORTANCE

Certain changes continually taking place in the
industrial and business environment must be considered
both economically and practically.
These include:
1.
2.
3.
4.
The globalization of both the market and the producer
The growth of the service sector
the computerization of all facets of an enterprise
The ever-expanding applications of the Internet and
Web
4.
5.
The focus of the reliability and quality control manager is to:
1.
2.
3.

The only way a business or enterprise can grow and
increase its profitability is by increasing its productivity.
Productivity improvement refers to the increase in
output per work-hour or time expended.
Maintain engineering specifications
Satisfy customers with the product’s quality
Level reliability over its expected life
The production control manager is principally interested in:
1.
2.
Establishing and maintaining production schedules with
due regard for both customer needs.
The favorable economics obtainable with careful
scheduling.
The maintenance manager is primarily concerned with:


With a minimum of capital investment
A maximum of employee satisfaction
Minimizing facility downtime due to unscheduled
breakdowns and repairs.
Figure 1.1
Typical organization chart showing the influence of methods,
standards, and work design on the operation of the enterprise.
The fundamental tools that result in increased productivity
include:
1.
2.
3.

Methods
Time study standards (frequently referred to as work
measurement)
Work design
Since the production area within manufacturing
industries utilizes the greatest number of engineers in
methods, standards, and work design efforts
Traditional areas of opportunity for students enrolled in
engineering, industrial management, business administration,
industrial psychology, and labor– management relations are:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Work measurement
Work methods and design
Production engineering
Manufacturing analysis and control
Facilities planning
Wage administration
Ergonomics and safety
Production and inventory control
Quality control
The production area of an industry is key to success. Here
materials are:
1.
2.
3.
4.
5.
6.
Requisitioned and controlled
The sequence of operations, inspections, and methods
is determined
Tools are ordered
Time values are assigned
Work is scheduled, dispatched, and followed up
Customers are kept satisfied with quality products
delivered on time
Similarly, the methods, standards, and work design activity is the
key part of the production group.
Here more than in any other place:





People determine whether a product is going to be
produced on a competitive basis
Through efficient workstations
Tooling
Worker and machine relationships
Here is where they are creative in improving existing
methods and products and maintaining good labor
relations through fair labor standards.
The objective of the manufacturing manager is:
1.
2.
3.
Produce a quality product
On schedule
At the lowest possible cost
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
Cost is largely determined by manufacturing methods.
Time standards are the bases of standard costs.
Standards (direct and indirect) provide the bases for
measuring the performance of production departments.
Time is a common denominator for comparing
competitive equipment and supplies.
Good labor relations are maintained with equitable
standards and a safe work environment.
Methods work design and processes strongly influence
product designs.
Standards
provide
the
bases
for
preventive
maintenance.
Standards enforce quality.
Scheduling is based on time standards.
Methods, standards, and work design provide how the
work is to be done and how long it will take.
1.2 METHODS AND STANDARDS SCOPE
Methods engineering includes:
1.
2.
3.
4.
5.
6.
7.
Designing
Creating
Selecting the best manufacturing methods
Processes
Tools
Equipment
Skills to manufacture a product
When the best method interfaces with the best skills available, an
efficient worker–machine relationship exists.
Once the complete method has been established, a standard
time for the product must be determined.

Opportunities for savings through the applications of methods
engineering and time study.
As long as they continue to emphasize research and
development,
methods
engineering
through
technological innovation will be instrumental in their
ability to provide high-level goods and services.
Figure 1.3
The principal steps in a methods engineering program
METHODS ENGINEERING

The terms operation analysis, work design, work
simplification, and methods engineering and corporate
reengineering are frequently used synonymously.
Productivity improvement

the person is referring to a technique for increasing the
production per unit of time or decreasing the cost per
unit output
Methods Engineers Use A Systematic Procedure to Develop A
Work Center, Produce A Product, Or Provide A Service:
However, methods engineering, as defined in this text, entails
analyses at two different times during the history of a product.
1.
2.
responsible for designing and developing the various
work centers where the product will be produced.
must continually restudy the work centers to find a better
way to produce the product and/or improve its quality.
1. Select the Project

represent either new products or existing products that
have a high cost of manufacture and a low profit.

Also, products that are currently experiencing difficulties
in maintaining quality and are having problems meeting
competition are logical projects for methods
engineering.
In recent years, this second analysis has been called corporate
reengineering.


business must introduce changes if it is to continue
profitable operation.
desirable to introduce changes outside the
manufacturing area.
2. Get and Present the Data

The more thorough the methods study during the planning stages,
the less the necessity for additional methods studies during the life
of the product.

Methods engineering implies
technological capability.
the
utilization
of
Research and development (R&D) leading to new technology is
therefore essential to methods engineering.
3. Analyze the Data

United States
Switzerland
Sweden
Netherlands
Germany
Norway
France
Israel
Belgium
Japan
Utilize the primary approaches to operations analysis to
decide which alternative will result in the best product or
service.
4. Develop the Ideal Method

The 10 countries with the highest R&D expenditures per worker, as
reported by the United Nations Industrial Development
Organization (1985), are:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Assemble all the important facts relating to the product
or service.
Select the best procedure for each operation,
inspection, and transportation by considering the
various constraints associated with each alternative,
including:
 Productivity
 Ergonomics
 Health and safety implications
5. Present and Install the Method

Explain the proposed method in detail to those
responsible for its operation and maintenance.

Consider all details of the work center, to ensure that the
proposed method will provide the results anticipated.
6. Develop a Job Analysis

Conduct a job analysis of the installed method to ensure
that the operators are adequately selected, trained,
and rewarded.
7. Establish Time Standards

The ability to produce more for less will result in more jobs
for more people for a greater number of hours per year.

Only through the intelligent application of the principles
of methods, standards, and work design can producers
of goods and services increase, while, at the same time,
the purchasing potential of all consumers grows.

Through these principles, unemployment and relief rolls
can be minimized.

Thus, reducing the spiraling cost of economic support to
nonproducers.
Establish a fair and equitable standard for the installed
method.
8. Follow up the Method


At regular intervals, audit the installed method to
determine if the anticipated productivity and quality are
being realized, whether costs were correctly projected.
IN SUMMARY
Methods engineering is the systematic close scrutiny of all direct
and indirect operations to:

Find improvements that make work easier to perform, in
terms of worker health and safety

Also, allow work to be done in less time with less
investment per unit (i.e., greater profitability).
WORK DESIGN
Principles of work design



Frederick W. Taylor








must be used to fit the task and workstation
ergonomically to the human operator.
typically forgotten in the quest for increased productivity.
Overly simplified procedures

1.3 HISTORICAL DEVELOPMENTS
result in machinelike repetitive jobs for the operators,
leading
to
increased
rates
of
work-related
musculoskeletal disorders.
Thus, it is necessary for the methods engineer to
incorporate the principles of work design into any new
method
Shop Management



Standards are the end result of time study or work
measurement.

This technique establishes a time standard allowed to
perform a given task, based on measurements of the
work content of the prescribed method
Time study analysts use several techniques to establish a
standard:
1.
2.
3.
4.
5.
6.
A stopwatch time study
Computerized data collection
Standard data
Predetermined time systems
Work sampling
Estimates based on historical data
Wage payment activity

performed by the same group responsible for the
methods and standards work.
Famous paper
which included the elements of Scientific Management
113 plants that had installed scientific management
Pig-iron experiment

most celebrated demonstrations of his principles.
Taylor–White process of heat treatment for tool steel


STANDARDS

founder of modern time study in this country.
However, time studies were conducted in Europe many
years before Taylor’s time.
Taylor died of pneumonia in 1915, at the age of 59.
Taylor began his time study work in 1881
serving as an apprentice.
he evolved a system based on the “task.”
the work of each employee be planned out by the
management at least one day in advance.
breaking up the work assignment into small divisions of
effort known as “elements”
Taylor’s well-known contributions
hardening a chrome–tungsten steel alloy without
rendering it brittle
In 1760, Jean Rodolphe Perronet,


French engineer
made extensive time studies on the manufacture of No.
6 common pins.
Charles W. Babbage


English economist
conducted time studies on the manufacture of No. 11
common pins.
MOTION STUDY AND THE WORK OF THE GILBRETHS
Frank and Lilian Gilbreth




were the founders of the modern motion-study
technique, which may be defined as the study of the
body motions
introduced his ideas and philosophies into the
bricklayer’s trade in which he was employed.
Frank died death at the age of 55
Lilian passed away in 1972 at age of 93.
Adjustable scaffold and operator training

OBJECTIVES OF METHODS, STANDARDS, AND WORK DESIGN
The principal objectives of methods, standards, and work design
are:
1)
2)
To increase productivity and product reliability safely.
To lower unit cost, thus allowing more quality goods and
services to be produced for more people.
he was able to increase the average number of bricks
laid to 350 per worker per hour.
Micromotion study


technique of filming motions to study them known as.
The study of movements through the aid of the slowmotion moving picture is by no means confined to
industrial applications.
Cyclegraphic

involves attaching a small electric lightbulb to the finger
or hand or part of the body
Humane approach

Chronocyclegraph

its electric circuit is interrupted regularly, causing the light
to flash.



HENRY LAURENCE GANTT
Workers tend to fear methods and time study
Henry Laurence Gantt



must be well versed in the study of human behavior and
accomplished in the art of communication.
be good listeners, respecting the ideas and thinking of
others.
to use the questioning attitude emphasized by the
Gilbreths, Taylor, and the other pioneers in the field.
The idea that there is “always a better way”

invented the task and bonus system or earned-hour
plan.
Gantt advocated a livable wage with a sizable bonus
for performance over 100%.
interested in operator selection, training, and motivation.



RALPH M. BARNES
for they see that the results are an increase in
productivity.
To them, this means less work and consequently less
pay.
unpleasant experiences with efficiency experts.
To many workers, motion and time study is synonymous
with the speedup of work and the use of incentives to
spur employees to higher levels of output.
Ralph M. Barnes



first and best-known professors of engineering in the
field of work measurement.
His achievements included writing the longest
published text on work measurement.
numerous methods studies of activities with motion
picture cameras and developed rating films for training
time study technologists.
SUMMARY

Industry, business, and government are in agreement
that the untapped potential for increasing productivity
is the best hope for dealing with inflation and
competition.

The principal key to increased productivity is a
continuing application of the principles of methods,
standards, and work design.
EMERGENCE OF WORK DESIGN
Work design


Chapter 2
is a relatively new science that deals with designing the
task, work station, and working environment to fit the
human operator better.
In the United States, it is more typically known as human
factors, while internationally it is better known as
ergonomics, which is derived from the Greek words for
work (erg) and laws (nomos).
Technical organizations





Most crucial step: identification of the problem in a clear and
logical form.
have contributed much toward bringing the science of
time study, work design, and methods engineering up to
present-day standards.
Maintaining the practice of industrial engineering on a
professional level;
Fostering a high degree of integrity among the members
of the industrial engineering profession;
Encouraging and assisting education and research in
areas of interest to industrial engineers;
Promoting the interchange of ideas and in formation
among members of the industrial engineering profession
In the area of work design, the first professional
organization, the Ergonomics Research Society, was
founded in the United Kingdom in It started the first
professional journal, Ergonomics, in 1957.






Problems could be large amounts of scrap or rework,
excessive material handling, in terms of either cost or
distance

Technical considerations may include:
1. Processing techniques that need to be
improved.
2. Quality control problems due to the method.
3. Product performance problems compared to
the competition.
Human considerations may involve:
1. Highly repetitive jobs.
2. Leading to work-related musculoskeletal
injuries.
3. High-accident-rate jobs.
4. Excessively fatiguing jobs.
5. Jobs about which workers constantly
complain.

a
direct
bearing
on
emerged during the 1940s
need for better project planning and control of complex
military projects.
useful in identifying problems in an industrial setting.
Bottleneck
Practitioners of methods, standards, and work design have come
to realize that such factors as:
Age
Health and well-being,
Physical size and strength,
Training attitudes,
Job satisfaction
Motivation response have
productivity.
evolved from Japanese quality circles of the early 1960s
improving quality and reducing costs in their
manufacturing processes.
Gantt and PERT charts
Currently, there are well over 5,000 members organized
in 20 different technical groups.
PRESENT TRENDS






So the methods engineer uses appropriate tools to do a
better job in a shorter time.
Pareto analysis and fish diagrams
The Institute of Industrial Engineers (IIE) was founded in 1948 with
the purposes of:

Good methods engineering program: will follow an orderly
process

ORGANIZATIONS

PROBLEM-SOLVING TOOLS

The first four exploratory tools are most typically used in
the analyst’s office.
Job/worksite analysis guide



helps identify problems within a particular area,
department, or worksite
provides a subjective identification of key worker, task,
environmental, or administrative factors
necessary first step before extensive quantitative data
are collected on the present method.
Get and present the data

The next five tools are used to record the present
method, and they comprise the second step of methods
analysis,

in response to the need to manage complex defense
projects and systems better.

shows the anticipated completion times for various
project activities as bars plotted against time on the
horizontal axis.

Actual completion times are shown by shading the bars
appropriately.

provides a quick snapshot of the progress of the project
at any given time.
be utilized for sequencing machine activity on the plant
floor.

Develop the ideal method.


The final three tools are more useful as a quantitative
approach in the fourth step of methods analysis,
Once the facts are presented clearly and accurately,
they are examined critically
2.1 EXPLORATORY TOOLS
PERT CHARTING
Program Evaluation and Review Technique(PERT)



PARETO ANALYSIS



technique developed by the economist Vilfredo Pareto
to explain the concentration of wealth.
items of interest are identified and measured on a
common scale and then are ordered in descending
order, as a cumulative distribution.
transformed to a straight line using a lognormal
transformation
80-20 rule

20 percent of the ranked items account for 80 percent
or more of the total activity


Events (represented by nodes)

concentrates the greatest effort on the few jobs that
produce most of the problems.
FISH DIAGRAMS

also known as cause-and-effect diagrams,
were developed by Ishikawa in the early 1950s
while he was working on a quality control project for
Kawasaki Steel Company.
The process is continued until all possible causes are
listed.
worked quite successfully in Japanese quality circles

The effect, as the “fish head”

The causes, as the “fish bones”




The principal causes are typically subdivided into five or six major
categories:
are positions in time that show the start and completion
of a particular operation or group of operations.
Arc: each operation or group of operations in a department is
defined as an activity.

Methods analyst

network diagram or critical path method,
It is a planning and control tool
graphically portrays the optimum way to attain some
predetermined objective, generally in terms of time.
was employed by the U.S. military in the design of such
processes as the Polaris missile
Methods analysts usually use PERT charting to improve
scheduling through cost reduction or customer
satisfaction.
Each arc has an attached number representing the time
needed to complete the activity.
Dummy activities



activities that utilize no time or cost
necessary to maintain a correct sequence, and are
shown as dotted lines.
Typically used to indicate precedence or dependencies,
each activity has a unique set of nodes.
Minimum time

The minimum time needed to complete the project is
the longest path from node 1 to node 12.
Time flexibility (freedom)


is referred to as float
the amount of time that a noncritical activity can be
lengthened without delaying the project’s completion
date.
Critical path

can be found through trial and error
1.
The human
2.
Machines
3.
Methods
4.
Materials
5.
Environmental
Latest start time latest time an activity can start without delaying
the project.
6.
Administrative—each of which is further subdivided into
sub-causes.
Latest finish time: minimum of the latest start times of the
emanating activities
Two predecessor activities

the earliest start is computed as the maximum of the
previous earliest furnishes
Good diagram

will have several levels of bones and will provide a very
good overview of a problem and its contributing factors.
2.2 RECORDING AND ANALYSIS TOOLS
OPERATION PROCESS CHART
GANTT CHART

first project planning and control technique to emerge
during the 1940s



shows the chronological sequence of all operations,
inspections, time allowances, and materials used in a
manufacturing
subassemblies to the main assembly.
details at a glance


an ideal plant layout
methods analysts: developing
improving existing ones.
new
layouts
and
Two symbols are used
1.
2.
Right-hand column: provides space for the analyst to enter
comments or make recommendations for potential changes.
Longer a part stays in storage or is delayed, the more cost it
accumulates and the longer the customer must wait for delivery.
A small circle denotes an operation.
A small square denotes an inspection.
Operation: intentionally transformed
Inspection: examined to determine its conformity
Vertical lines: indicate the general flow of the process
Horizontal lines: indicate material
Figure 2.6 Flowcharting Conventions
FLOW DIAGRAM
Time values: based on either estimates or actual measurements
FLOW PROCESS CHART






greater detail than the operation process chart.
it is not usually applied to entire assemblies but rather
for each component of an assembly.
valuable in recording nonproduction hidden costs
the information it provides can lead to a reduction of
both the quantity and duration of these elements.
exceptionally valuable in showing how the layout of a
plant can be improved.
show all the moves and storage delays encountered by
an item as it goes through the plant.




A pictorial representation of the layout
showing the locations of all activities
analysts identify each activity by symbols and numbers
corresponding to those appearing on the flow process
chart.
helpful supplement to the flow process chart because it
indicates backtracking and possible traffic congestion
areas, and it facilitates developing an ideal plant layout.
Five symbols are used:
1.
2.
3.
4.
5.
A small circle denotes an operation.
A small square denotes an inspection
A small arrow signifies transportation, which can be
defined as moving an object from one place to another,
A large capital D indicates a delay, which occurs when
a part is not immediately permitted to be processed at
the next workstation.
An equilateral triangle standing on its vertex signifies a
storage, which occurs when a part is held and protected
against unauthorized removal.
Two types of flowcharts are currently in general use:
1.
Product or material  provides the details of the events.
2.
Operative or person  how a person performs an
operational sequence.
WORKER AND MACHINE PROCESS CHARTS





used to study, analyze, and improve one workstation at
a time.
shows the exact time relationship between the working
cycle of the person and the operating cycle of the
machine.
clearly shows the areas in which both idle machine time
and idle worker time occur.
These areas are generally a good place to start in
effecting improvements.
The analyst should never use overall stopwatch readings
in the construction of the chart.
Many machine tools are either:
1.
Completely
machine)
automatic
(the
automatic
screw
2.
Semiautomatic (the turret lathe)
Machine coupling



having one employee operate more than one machine.
increases the percentage of “effort time”
greater incentive earnings are possible if a company is
on an incentive wage payment plan.
The longer the cycle time of the operation being charted, the
shorter the distance per decimal minute of time.
The productive time plus the idle time of the worker must equal the
productive time plus the idle time of each machine that the
worker operates.
Accurate elemental time values are necessary before the worker
and machine chart can be constructed.
RANDOM SERVICING

Completely random servicing situations are those cases
in which it is not known when a facility needs to be
serviced or how long servicing takes.
Mean values

are usually known or can be determined; with these
averages,
Laws of probability

can provide a useful tool in determining the number of
machines to assign a single operator.
COMPLEX RELATIONSHIPS



the servicing time is relatively constant, but the machines
are serviced randomly.
the time between breakdowns is assumed to have a
particular distribution.
As the number of machines increases and the
relationship between the operator and machines
becomes more complex, machine interference and
consequent delay times increase.
LINE BALANCING


GANG PROCESS CHARTS





an adaptation of the worker and machine chart.
several workers are needed to operate one machine
effectively.
shows the exact relationship between the idle and
operating cycles of the machine and the idle and
operating times per cycle of the workers who service
that machine.
reveals the possibilities for improvement by reducing
both idle operator time and idle machine time.
company is employing two more operators than are
needed.


The problem of determining the ideal number of workers
to be assigned to a production line is analogous to that
of determining the number of workers to be assigned to
a workstation
one that is very often encountered, is one in which
several operators, each performing consecutive
operations, work as a unit.
the rate of production is dependent on the slowest
operator.
the operator will probably better the standard in view of
the performance of the operators on the line with less
work content in their assignments.
Line be perfectly balanced



standard minutes to perform an operation would be
identical for each member of the team.
“standard minutes to perform an operation” is not really
a standard. It is only a standard to the individual who
established it.
Also, involves dividing a work element
Sequence of individual work elements
2.2 QUANTITATIVE TOOLS, WORKER AND MACHINE RELATIONSHIPS

SYNCHRONOUS SERVICING


Assigning more than one machine to an operator
seldom results in the ideal case
where both the worker and the machine are occupied
during the whole cycle.
The fewer the restrictions on the order, the greater the
probability that a favorable balance in the work
assignments will be achieved.
Zoning restraints


A zone represents a subdivision that may or may not be
physically separated or identified from other zones in the
system.
may help to identify physically specific stages of a
component
n = No. of machines the operator is assigned
l = total operator loading and unloading time per machine
SUMMARY
m = total machine running time
Pareto and fish diagrams
Assume a total cycle time of 4 min to produce a product, as
measured from the start of the unloading of the previously
completed product to the end of the machine cycle time.
Operator servicing, which includes both the unloading of the
completed product and the loading of the raw materials, is 1 min,
while the cycle time of the automatic machine cycle is 3 min.


used to select a critical operation
to identify the root causes and contributing factors
leading to the problem.
Gantt and PERT charts: project scheduling tools.
Gantt chart: only a good overview
PERT chart: quantifies the interactions between different activities.
Job/worksite analysis guide

primarily used on a physical walkthrough
Operation process chart

provides a good overview of the relationships between
different operations and inspections on assemblies
involving several components.
Flow process chart


its ability to satisfy given needs.
considered when reviewing the design,
Methods analysts should be well versed in the details of
cost and should be fully aware of what unnecessarily
close tolerances
the company can reduce the costs of inspection,
minimize scrap, diminish repair costs, and keep quality
high.
Inspection: verification of quantity, quality, dimensions, and
performance.

provides more details for the analysis of manufacturing
operations, to find hidden or indirect costs, such as delay
time, storage costs, and material handling costs.
Flow diagram





Spot inspection: is a periodic check to ensure that
established standards are being realized.
Lot-by-lot inspection: is a sampling procedure in which a
sample is examined to determine the quality of the
production run or lot.

useful supplement to the flow process chart in
developing plant layouts.
3.4 MATERIAL
FINDING A LESS EXPENSIVE AND LIGHTER MATERIAL
can be used as anchor points from which to judge the application
of new materials.
Chapter 3
Operation Analysis



Methods analysts use operation analysis to study all
productive and nonproductive elements of an
operation, while maintaining or improving quality.
simplifying operational procedures and material
handling and by utilizing equipment more effectively.
analysis takes place and the various components of the
proposed method crystallize
Lean manufacturing



repackaged format
originated with the Toyota Motor Corporation
means of eliminating waste in the aftermath of the 1973
oil embargo.
A material that was not competitive in price yesterday may be
very competitive today. One company used Micarta spacer bars
between the windings of transformer coils. Separating the
windings permitted the circulation of air between the windings.
An investigation revealed that glass tubing could be substituted
for the Micarta bars at a considerable savings. The glass tubing
was less expensive, and it met service requirements better
because the glass could withstand higher temperatures.
Furthermore, the hollow tubing permitted greater air circulation
than did the solid Micarta bars. Another company also used a less
expensive material that still met service requirements in the
production of distribution transformers. Originally, a porcelain
plate separated and held the wire leads coming out of the
transformers. The company found that a fullerboard plate stood
up just as well in service, yet was considerably less expensive.
Today, one of the many types of plastic available would provide
an even cheaper solution.
FINDING A MATERIAL THAT IS EASIER TO PROCESS
3.1 OPERATION PURPOSE


the most important of the nine points of operation
analysis
devise some way to get the same or better results at no
additional cost.
Analyst’s cardinal rule

is to try to eliminate or combine an operation before
trying to improve it.
Eliminating an activity



the task/process should not be simplified or improved,
but eliminated entirely.
saves money on the installation of an improved method
there is no interruption or delay because no improved
method is being developed, tested, and installed.
Unnecessary operations


frequently result from improper planning when the job is
first set up.
often develop because of the improper performance of
a previous operation.
Second operation


must be done to “touch up” or make acceptable the
work done by the first operation.
the analyst was able to eliminate the touch-up
operation by considering that an unnecessary operation
may have developed of the improper performance
3.3 TOLERANCES AND SPECIFICATIONS
Some materials are usually more readily processed than others.
Referring to handbook data on the physical properties usually
helps analysts discern which material will react most favorably to
the processes to which it must be subjected in its conversion from
raw material to finished product.
machinability varies inversely with hardness, and hardness usually
varies directly with strength. Today the most versatile material is
reinforced composites. Resin transfer molding can produce more
complex parts advantageously from the standpoint of quality and
production rate than most other metal and plastic forming
procedures. Thus, by specifying a plastic made of reinforcing
carbon fibers and epoxy, the analyst can substitute a composite
for a metal part, at both a quality and a cost advantage. This step
is also addressing the muda of inappropriate processing.
USING MATERIAL MORE ECONOMICALLY The possibility of using
material more economically is a fertile field for analysis. If the ratio
of scrap material to that actually going into the product is high,
then greater utilization should be examined. For example, if the
material put into a plastic compression mold is preweighed, it may
be possible to use only the exact amount required to fill the cavity;
excessive flash can also be eliminated. In another example, the
production of stampings from sheet metal should utilize multiple
dies carefully arranged to assure maximum use of material. Given
consistent raw material and standard-sized dies, this typically is
done through the use of CAD-assisted layout, yielding efficiencies
exceeding 95% (i.e., less than 5% scrap). Similar approaches are
utilized in the garment industry in the layout of patterns on cloth
and the glass industry for the cutting of different sized windows.
However, if the material is not consistent, then problems arise and
the layout may still need to be performed by a human operator.
The production of leather seats for automobiles requires layout of
cutting dies on a tanned hide before entering a rolling press,
which applies pressure on the dies to cut the leather in
appropriate patterns. The operator needs to be highly skilled in
handling variably sized cow hides full of imperfections from brands
and barbed wire, especially to maximize the usage of quite
expensive leather (see Figure 3.6). Many world-class
manufacturers are finding it not only desirable, but absolutely
necessary, to take weight out of existing designs. For example,
Ford engineers all looking a 40 percent weight reduction to
achieve an 80 mi/gal fuel efficiency for the Taurus. This will require
the cladding of stainless steel to highstrength aluminum to replace
chrome-plated steel bumpers, as well as a much greater use of
plastics and structural composites to replace ferrous components.
Similar weight reduction is taking place on many other well-known
products, such as washing machines, video cameras, VCRs,
suitcases, and TV sets. Today, powder coating is a proven
technology that is replacing many other methods of metal
finishing. Coating powders are finely divided particles of organic
polymers (acrylic, epoxy, polyester, or blends) that usually contain
pigments, fillers, and additives. Powder coating is the application
of a suitable formulation to a substrate, which are then fused into
a continuous film by the application of heat, forming a protective
and decorative finish. In view of current environmental regulations
affecting traditional metal finishing operations, such