Optimizing High-Mix Low-Volume
Operations
Shahrukh A. Irani
Department of Integrated Systems Engineering
The Ohio State University
Columbus, OH 43210
PHONE: (614) 688-4685
EMAIL: irani.4@osu.edu
WEBSITE: http://ise.osu.edu/biosketch_SIrani.cfm
Agenda
 Types of Manufacturing Systems
 What type of manufacturing system do you manage?
 What makes jobshops (high-mix, low-volume, MTO) different from
any “Toyota-type” plant?
 Limitations of the (Toyota)Lean tools
 Examples of high-mix low-volume (HMLV) manufacturing systems
 CASE STUDY: Optimization of the layout of an entire plant
 CASE STUDY: Optimization of the setup on a press
 A Toolbox for High-Mix Low-Volume Manufacturers
QUANTITY
(Volume)
Spectrum of Manufacturing Systems
Assembly Lines or Transfer Lines
Flexible Flowshops
Manual Cells
High
Flexible Mfg.Cells
Jobshops
Low
Low
High
MIX
(Variety)
MIX (R)
Outliers
In a Part Family
What is Your Manufacturing System?
P
Lean for Toyota ≠ Lean for Jobshops
• Jobshops ≠ Assembly Facilities
–
–
–
–
–
–
High mix of products i.e. many different routings
Part families may not be known
Product mix segmentation must be done
Setup times, cycle times, lot sizes, etc. vary significantly
Wide variety of product designs and equipment types
Typical facility has a Process Layout (= batch-and-queue)
• Different (and Difficult) Business Environment
–
–
–
–
–
–
Demand is unstable
Lot sizes change
Customer loyalty and sanity are non-existent
Production schedules are driven by due dates (not Takt Time)
Shifting capacity constraints
Due dates are different and subject to frequent changes
Many Lean Tools are NOT Universal











Strategic Planning
Top-Down Leadership
Motivated Workforce
5S
Total Productive Maintenance
Setup Reduction
Error-Proofing
Quality at Source
Visual Workplace
Right-sized Equipment
Standardization of Work
X Right-sized (= Inflexible) Machines
X Kaizen Events (Mainly by Operators)
X 20th (not 21st) Century Managers
X Pencil-and-Paper Problem Solving
X Value Stream Mapping
X One-Piece Flow Cells
X Product-specific Kanbans
X FIFO Sequencing of Orders
X Pacemaker Scheduling
X Inventory Supermarkets
X Scheduling using Takt Time
X Heijunka/Load Leveling
X Assembly Line Balancing
How to Recognize a High-Mix Low-Volume
Manufacturing System?
Forge Shop (≈500 Routings)
MTO Industrial Scale Fabrication Facility
761
HSTUD/
761PEM
LASER
761AMADA
761
FORM
764BURNM
761PUNCH
770PANG
761
761
DBURR TWELD
761
POLSH
761
SPWLD
761ASY
764BRAKE
764SHR20
764UNPUN
764SUBMR
764BEVLR
812ASM
764PSMA
764CDROB
770WHLBR
Z
763DRLPR
763SHR16
763PRBRK
Y
763BDSAW
763ACRO
Y
Z
763FSROB
770MODBO
764/763 WELDM
763IRONW
763
MONRC
X
X
763
MON45
771
VIKIN
771
SNDBL
STORAGE LOCATIONS
771
FSWHL
771HCFIN/
771TEXTR
811ASM
Shipping
Flexible Machining Cell
2
3
1
6
4
5
7
9
8
10
11
12
Finish Grinding Department
Factory Layout Optimization at Ulven Forging
Current State
Future State
Actions Taken
 An additional processing area was created in the Drop
Hammer building where cleaning,finishing,packaging and
shipping were consolidated.
 The 158 ton Trim Press was replaced by a 440 ton press that
was positioned next to the 5000# Hammer. This eliminated
the transportation of large forgings to a distant 350 ton Trim
press. Also, a 350 kW induction heater and conveyor were
purchased and co-located with this press to form an Upset
Forging cell.
 A new 2.5” Upsetter was purchased and positioned next to
the 3000# Hammer to form an Upset Forging cell.
Actions Taken (contd.)
 The 1.5” Upsetter was replaced with a faster machine and
positioned next to the 700 ton Press to form an Upset Forging
cell.
 A crane was installed over the 5000# Hammer to reduce
piston change-out time, reduce die key tightening time and to
facilitate product movement in the area.
 A portable Marvel Hacksaw and 1.5” Bar Shear were
acquired.
 A CNC Mill was acquired and positioned next to the EDM
machine to reduce vendor costs and lead times for die
sinking.
Benefits
 Approximately 5% cost savings on annual sales of $ 6 million
 WIP reductions were significant
 Lead times quoted to customers were reduced
 Throughput ($ales) increased
Since this company is a defense supplier, they were
reluctant to release financial and delivery performance data
that could be seen by their customers (Defense Logistics
Agency and Department Of Defense)
Press Setup Optimization at Hirschvogel
Observe and Document the Press Setup
Work Locations around the Press
Sequence of Tasks in Press Setup
Operator Motion Traffic around the Press
New Workstation Layout for the Press
5
14
11
15
1
10
12
8
17
22
9
16
7
6
Operator Motion in Previous Layout
Operator Motion in New Layout
Press Setup Time: Before vs. After
Activities
Operations
Inspections
Transport.
Storage
Delays
Total
Current Process
No.
Time
%
247
1:32:07
71%
32
0:11:28
9%
135
0:17:54
14%
0
0:00:00
0%
12
0:09:01
7%
426
2:10:30
100%
Redesigned Process
No.
Time
%
235
1:28:53
79%
31
0:11:23
10%
92
0:12:45
11%
0
0:00:00
0%
0
0:00:00
0%
358
1:53:01
100%
Difference
No.
Time
-12
-0:03:14
-1
-0:00:05
-43
-0:05:09
0
0:00:00
-12
-0:09:01
-68
-0:17:29
20:10
Initial Time Taken
Time (in min.)
17:17
14:24
11:31
08:38
05:46
02:53
00:00
Revised Time Taken
Estimation of Increased Production
Potential Increase in Production = [EPT – (# of Setups * Time/Setup)] / Cycle Time per Part
22,500
20,000
Number of Parts Produced
17,500
15,000
12,500
10,000
7,500
5,000
2,500
0
0
5
10
15
20
25
30
Number of Setups
35
40
45
50
Estimation of Increased $ales
Potential Increase in Revenue = [EPT – (# of Setups * Time/Setup) / Cycle Time per Part] * $/Part
$350,000.00
Revenues from Extra Production
$300,000.00
$250,000.00
$200,000.00
Lowest Revenue per Part
Average Revenue per Part
$150,000.00
Highest Revenue per Part
$100,000.00
$50,000.00
$0
5
10
15
20
25
30
Number of Setups
35
40
45
50
Benefits
Savings in Setup Time
Category
Initial
Proposed % Decrease
Setup Time (min)
130.5
60.86
53.3%
Number of Activity Steps
426
358
16.0%
Distance travelled by Operator (steps)
1167
797
31.70%
Potential Increase in Revenue
Part #
Demand
Price/ Part
A1234
B3456
D6755
6,000
3,300
7,500
$
$
$
Extra Parts
16800
Extra Revenue
15.55
7.00
12.50
Revenue
$
$
$
93,300.00
23,100.00
93,750.00
$ 210,150.00
Parallel Task Scheduling for Press Setup
 1 Operator
113.02 min (Current State)
 2 Operators
60.86 min (Parallel Execution of Activities)
 3 Operators
60.86 min (Unnecessary, 2 operators are OK)
Gantt Chart for Optimized 2-Person Setup Process
Op #1
Op #2
Optimization could Enhance Every Lean Tool
Value Stream Mapping
Multi-Period
Slotting of
Orders
Demand
Forecasting
Work Order
Release
Current Project at Pompano Beach
Warehouse
Design
Work Center
Scheduling
WIP
Inventory
Control
Scheduling
Supplier
Deliveries
Cell
Design
Scheduling
Material
Handlers
A Toolbox for HMLV Manufacturers
“4H” LEADERSHIP
• Walks the Gemba
• Knowledgeable
• Beyond TLSS
• Competitive
• Respects Employees
• Efficient Fire
Fighters (Risk
Managers)
• Change Managers
• Invested in Talent
and Technology
ENGAGED
WORKFORCE
• Lean Thinkers
• “Factory of
One” Problem
Solvers
• Empowered
• Multi-skilled
• Team-oriented
• IT Savvy
• Collaborative
CURRENT STATE
FUTURE STATE
MORE….
LEARNING
ENTERPRISE
INDUSTRIAL
ENGINEERING
• Work Measurements
• Facility Layout
• Ergonomics
• Scheduling
• Variety Control
• Value Analysis/Value
Engineering
• DFMA
• Flexible Mfg. Cells
• Product/Process
Standardization
• Product Mix
Rationalization
• etc.
• Cafeteria Chats
• E-newsletter
• Wikis
• Kaizens
• Online Chat
Groups
• Idea Boards
• Annual
Conference
• Resource Center
- E-books
- Case Studies
- Videos
- Online Apps
- etc.
COMPETING
THROUGH
INNOVATION
• Value Network
Mapping
• M3 Facilities
• Flexible Focus
(GT)
• Product Mix
Segmentation
• ERP+FCS+MES
• IT-enabled JIT
Communications
• Virtual Cells and
Distributed Teams
• Water Striders
• Real-time Order
Tracking
• PLM+CAPP
• Agile Suppliers
UNIVERSITY
PARTNERSHIPS
• Co-Curricular
Projects
• Co-ops
• Internships
• Faculty R&D
• Executives on
Loan
• Factories as
“Test Beds”
Acknowledgements
The PRO-FAST Program is enabled by the
dedicated team of professionals representing
the Defense Logistics Agency, Department of
Defense and industry. These team mates are
determined to ensure the Nation’s forging
industry is positioned for the challenges of the
21st Century. Key team members include: R&D
Enterprise Team (DLA J339), Logistics
Research and Development Branch (DLA –
DSCP), and the Forging Industry Association
(FIA).
Acknowledgements
Project Champion: Craig Kaminski
Project Engineer: Haydn Garrett
Project Champion: John Wilbur
Project Engineers: Thomas Slauta
Project Champion: Joe Kracheck
Project Engineer: John Lucas
Project Champion: Kevin Shaw
Project Engineer: Greg Muniak
Project Champion: Dick Johnston
Project Engineer: Todd Sheppard
Jon Tirpak
Russell Beard
Vicky McKenzie
Project Champion: Andrew Ulven
Project Engineer: Jim Huiras
Dan Gearing
W
W E B E R M E T A L S , IN C .
A L UM IN UM AN D T IT AN IU M F OR G ING S
W
Project Champion: Thomas Stys
Project Engineer: Jorge Alvarez
PFAST Development Team
Dr. Rajiv Ramnath
Dr. Rajiv Shivpuri
Questions?