Toyota production system

Tai Lieu Chat Luong


TOYOTA
Production System
An Integrated Approach
to Just-In-Time

Fourth Edition



TOYOTA
Production System
An Integrated Approach
to Just-In-Time

Fourth Edition

Yasuhiro Monden


CRC Press
Taylor & Francis Group
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© 2012 by Taylor & Francis Group, LLC
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Version Date: 2011919
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Contents
Foreword to the First Edition........................................................... xxiii
Preface to the Fourth Edition............................................................. xxv
Preface to the Third Edition.......................................................... xxxvii
Preface to the Second Edition...............................................................xli
Acknowledgments.............................................................................. xliii
About the Author.................................................................................. xlv

Section 1 Total System and
Implementation Steps
Chapter 1 Total Framework of the Toyota Production System......... 3
§ 1 Primary Purpose....................................................................3
Profit through Cost Reduction..............................................3
Elimination of Overproduction.............................................4
Quantity Control, Quality Assurance, Respect for
Humanity..................................................................................6
Just-in-Time and Autonomation...........................................6
Flexible Workforce and Originality and Ingenuity............8
JIT Production.........................................................................8
§ 2 Kanban System.......................................................................9
Maintaining JIT by the Kanban System...............................9
Information via Kanban.......................................................10
Adapting to Changing Production Quantities..................10
§ 3 Production Smoothing........................................................11
Production in Accordance with Market Demand............11
Determining the Daily Production Sequence...................12
Adapting to Product Variety by General-Purpose
Machines.................................................................................13
§ 4 Shortening Setup Time........................................................13

v


vi ã Contents
Đ 5 Process Layout for Shortened Lead Times and
One-Piece Production................................................................14
§ 6 Standardization of Operations...........................................15
§ 7 Autonomation.......................................................................16

Autonomous Defects Control System.................................16
Visible Control System..........................................................17
§ 8 Improvement Activities.......................................................17
§ 9 The Goal of TPS....................................................................18
The Ultimate Goal of TPS....................................................18
To Improve Margin Ratio, Costs Must Be
Reduced, since Profit = Revenue – Costs.......................18
To Improve Turnover Ratio, Lead Time Must
Be Reduced.........................................................................19
Another Measure of the Integrated Goal:
“JIT Cash-Flows”................................................................... 20
Motivational Effects of the JIT Cash Flow Measure.........21
Control Measure at the Top Management Level
of the Whole Supply-Chain.............................................21
Control Measure at the Level of Plant Managers
and Supervisors.................................................................22
Control Measures at the Level of Shop Floor
Operators...........................................................................23
§ 10 Summary.............................................................................23
Chapter 2 Implementation Steps for the Toyota Production
System................................................................................ 25
§ 1 Introductory Steps to the Toyota Production System.....25
Step 1: Upper Management Plays a Key Role.....................25
Step 2: Establish a Project Team..........................................26
Step 3: Prepare an Implementation Schedule and
Set Goals to Be Achieved within the Schedule..................26
Step 4: Introduce a Pilot Project..........................................26
Step 5: Move from a Downstream Process to an
Upstream Process..................................................................26
Application Order of JIT Techniques.................................27

§ 2 Introduction of JIT at Toyo Aluminum—
A Case Study...............................................................................29


Contents  •  vii

Section 2  Subsystems
Chapter 3 Adaptable Kanban System Maintains Just-In-Time
Production......................................................................... 35
§ 1 Pull System for JIT Production..........................................35
§ 2 What Is a Kanban?...............................................................36
How to Use Various Kanban................................................41
Two Methods of Utilizing Production-Ordering
Kanban................................................................................... 43
§ 3 Kanban Rules........................................................................45
Rule 1—The Subsequent Process Should Withdraw
the Necessary Products from the Preceding Process
in the Necessary Quantities at the Necessary Point
in Time....................................................................................45
Whirligig........................................................................... 46
Constant-Cycle and Round-Tour MixedLoading System................................................................ 46
Rule 2—The Preceding Process Should Produce
Its Products in the Quantities Withdrawn by the
Subsequent Process................................................................47
Rule 3—Defective Products Should Never Be
Conveyed to the Subsequent Process................................. 48
Rule 4—The Number of Kanban Should Be
Minimized............................................................................. 48
Rule 5—Kanban Should Be Used to Adapt to
Small Fluctuations in Demand (Fine-Tuning

of Production by Kanban)....................................................49
§ 4 Other Types of Kanban.......................................................51
Express Kanban.....................................................................51
Emergency Kanban...............................................................53
Job-Order Kanban.................................................................53
Through Kanban....................................................................53
Common Kanban................................................................. 54
Cart or Truck as a Kanban.................................................. 54
Label........................................................................................55
Full-Work System..................................................................55


viii  •  Contents
Chapter 4 Supplier Kanban and the Sequence Schedule Used
by Suppliers........................................................................ 59
§ 1 Monthly Information and Daily Information................ 60
§ 2 Later Replenishment System by Kanban..........................61
How the Supplier Kanban Should Be Applied
to the Supplier........................................................................61
How the In-Process Kanban Will Circulate
in the Supplier’s Plant............................................................63
§ 3 Sequenced Withdrawal System by the Sequence
Schedule.......................................................................................65
Store Space and a Variety of Products................................67
How the Sequence Schedule Is Used
in the Assembly Lines of a Supplier................................... 68
§ 4 Problems and Countermeasures in Applying
the Kanban System to Subcontractors.....................................70
Criticism by the Communist Party against the
Toyota Production System....................................................70

§ 5 Guidance by the Fair Trade Commission Based on
the Subcontractors Law and the Anti-monopoly Law..........72
How Toyota Is Coping with Criticism................................74
§ 6 Supplier Kanban Circulation
in the Paternal Manufacturer...................................................79
Inventory Quantity of Purchased Parts..............................82
§ 7 Practical Examples of Delivery System and
Delivery Cycle.............................................................................83
Number of Supply Runs and Delivery Schedule
of Each Plant...........................................................................83
Kanban System and Adaptation to Emergency................ 86
Chapter 5 Smoothed Production Helps Toyota Adapt to
Demand Changes and Reduce Inventory........................ 89
§ 1 Smoothing of the Total Production Quantity..................89
Demand Fluctuation and Production Capacity Plan.......92
Adapting to Increased Demand......................................92
Adapting to Decreased Demand....................................93
§ 2 Smoothing Each Model’s Production Quantity..............93
Sequence Schedule for Introducing Models......................94
Sequence Schedule Sheet Sample........................................97


Contents  •  ix
Sequenced Withdrawal of Engines.....................................97
Two Phases of Production Smoothing............................... 99
Flexible Machinery Supporting Smoothed Production.... 99
§ 3 Comparison of the Kanban System with MRP.............101
§ 4 Summary of the Concept of Production Smoothing....102
Chapter 6 The Information System for Supply Chain
Management between Toyota, Its Dealers, and Parts

Manufacturers................................................................. 105
§ 1 The Order Entry Information System.............................105
Monthly Production System..............................................105
Master Production Schedule and Parts
Requirement Forecast.....................................................105
Daily Production System....................................................106
The Product Delivery Schedule and Sequence
Schedule...........................................................................106
The Sequenced Production Schedule................................109
Online System at the Distribution Stage..........................109
§ 2 The Information System between Toyota and
Parts Manufacturers................................................................110
Parts Requirement Forecast Table.....................................110
Network System within Toyota Group Using VAN........112
The Parts Distribution System...........................................113
§ 3 New Toyota Network System (TNS)................................114
Establishment of Type II Carrier by Toyota.....................114
Toyota’s New TNS (Toyota Network System)..................116
Parts Procurement Networks: JNX and WARP..............117
§ 4 Production Planning System at Nissan...........................118
Nissan’s Ordering Systems from Parts Suppliers............121
Daily Order......................................................................121
10-Day Order...................................................................121
Synchronized Order...................................................... 122
Special Order.................................................................. 122
Chapter 7 How Toyota Shortened Production Lead Time............. 123
§ 1 Four Advantages of Shortening Lead Time................... 123
§ 2 Components of Production Lead Time in a
Narrow Sense........................................................................... 124

x ã Contents
Đ 3 Shortening Processing Time through Single-Unit
Production and Conveyance...................................................125
Functional Division of Labor Using Specialized
Workers with “Lot” Production and Conveyance..........127
Product-Flow Layout with Multi-Skilled Workers
for One-Piece Production...................................................127
Comparison between Functional Division of
Processes and Multi-Process Handling: A Summary....129
Outline of Toyota’s Plants...................................................131
Shortening Processing Time through Small-Sized
Lot Production.....................................................................131
Advantages of Small Lots in the Production
of Different Products...........................................................132
Control Chart of Lot Size Reduction................................133
§ 4 Shortening Waiting Time and Conveyance Time........ 134
How to Balance Each Process........................................... 134
Shortening Waiting Time Caused by Pre-Process
Lot Size..................................................................................135
Two Steps for Conveyance Improvement.........................136
§ 5 A Broad Approach to Reducing Production Lead
Time...........................................................................................137
Five Principles for the Ideal Factory Automation...........138
Chapter 8 Machine Layout, Multi-Functional Workers, and
Job Rotation Help Realize Flexible Workshops............ 143
§ 1 Shojinka: Meeting Demand through Flexibility............143
§ 2 Layout Design: The U-Turn Layout.................................144
Improper Layouts................................................................146
Bird Cage Layouts...........................................................146

Isolated Island Layouts...................................................147
Linear Layouts.................................................................148
Combining U-Form Lines..................................................149
Cellular Manufacturing......................................................151
§ 3 Attaining Shojinka through Multi-Functional
Workers......................................................................................152
Cultivating Multi-Functional Workers through
Job Rotation..........................................................................153
Step 1: Rotation of Supervisors.....................................153


Contents  •  xi
Step 2: Rotation of Workers within Each Shop.......... 154
Step 3: Job Rotation Several Times per Day................156
Additional Advantages of Job Rotation............................158
Importance of the Line Chief: Giving Rest Time
and Job Rotation to Workers..............................................159
Chapter 9 One-Piece Production in Practice.................................. 161
§ 1 Requirements for One-Piece Production........................161
§ 2 Resistance to Working Standing Up...............................162
§ 3 Resistance to Multi-Skilling.............................................164
§ 4 Barriers to Autonomation.................................................164
How to Achieve Autonomation (in the Sense
of Decoupling Operators from Their Machines).............165
§ 5 Attaching Castors...............................................................167
§ 6 Smoothed Production........................................................168
§ 7 An Example of Improvement for One-Piece
Flow: A Factory Producing Cabinets
for Use as Flat-Screen Television Stands...............................169
Chapter 10 Standard Operations Can Attain Balanced

Production with Minimum Labor................................. 171
§ 1 Goals and Elements of Standard Operations.................171
§ 2 Determining the Components of Standard
Operations.................................................................................172
Determining the Cycle Time.............................................173
Determining the Completion Time per Unit..................173
Determining the Standard Operations Routine.............175
Yo-i-don System...................................................................178
One-Shot Setup....................................................................182
Determining the Standard Quantity
of Work-in-Process..............................................................183
Preparing the Standard Operations Sheet.......................184
§ 3 Proper Training and Follow-Up: The Key
to Implementing a Successful System....................................185
Chapter 11 Reduction of Setup Time—Concepts and Techniques...... 187
§ 1 Effects of Shortening the Setup Time..............................187


xii ã Contents
Đ 2 Setup Concepts...................................................................188
Concept 1: Separate the Internal Setup from the
External Setup......................................................................188
Concept 2: Convert as Much as Possible of the
Internal Setup to the External Setup................................188
Concept 3: Eliminate the Adjustment Process................189
Concept 4: Abolish the Setup Step Itself..........................191
§ 3 Concept Application..........................................................192
Technique 1: Standardize the External Setup Actions...192
Technique 2: Standardize Only the Necessary
Portions of the Machine.....................................................192

Technique 3: Use a Quick Fastener...................................192
Technique 4: Use a Supplementary Tool..........................194
Technique 5: Use Parallel Operations...............................195
Technique 6: Use a Mechanical Setup System.................196
Chapter 12 5S—Foundation for Improvements................................ 197
§ 1 5S Is to Remove Organizational Slack.............................197
§ 2 Visual Control................................................................... 200
Visual Seiri............................................................................201
Indicator Plate for Visual Seiton....................................... 203
Step 1—Decide Item Placement................................... 204
Step 2—Prepare the Container.................................... 204
Step 3—Indicate the Position for Each Item.............. 204
Step 4—Indicate the Item Code and Its Quantity..... 204
Step 5—Make Seiton a Habit........................................ 205
§ 3 Practical Rules for Seiton................................................. 207
Seiton of WIP...................................................................... 207
Rule 1: First-In, First-Out............................................. 207
Rule 2: Setup for Easy Handling.................................. 207
Rule 3: Regard Stock Space as Part of
Manufacturing Line...................................................... 208
Seiton of Jigs and Tools.......................................................210
Seiton of the Cutting Instruments, Measures, and Oil....211
Visual Controls for Limit Standards.................................213
§ 4 Seiso, Seiketsu, Shitsuke....................................................214
§ 5 Promotion of 5S System....................................................216
Point Photography...............................................................217


Contents  •  xiii
Chapter 13 Autonomous Defect Control Ensures Product Quality.... 219

§ 1 Development of Quality Management Activities..........219
§ 2 Statistical Quality Control................................................221
§ 3 Autonomation.................................................................... 223
§ 4 Autonomation and the Toyota Production System...... 225
Methods for Stopping the Line......................................... 225
Mechanical Checks in Aid of Human Judgment........... 227
Mistake-Proofing Systems for Stopping the Line.......... 228
Contact Method............................................................. 229
Altogether Method........................................................ 229
Action Step Method....................................................... 229
Visual Controls....................................................................231
Andon and Call Lights...................................................231
Standard Operations Sheets and Kanban Tickets......232
Digital Display Panels................................................... 234
Store and Stock Indicator Plates.................................. 234
§ 5 Robotics...............................................................................235
Robots and the Toyota Production System..................... 236
§ 6 Company-Wide Quality Control.................................... 236
All Departments Participate in QC..................................237
All Employees Participate in QC...................................... 238
QC Is Fully Integrated with Other Related
Company Functions........................................................... 238
Chapter 14 Cross-Functional Management to Promote
Company-Wide Quality Assurance and
Cost Management........................................................... 239
§ 1 Introduction........................................................................239
§ 2 Quality Assurance............................................................. 240
§ 3 Cost Management..............................................................241
Relations among Departments, Steps in Business
Activities, and Functions................................................... 244

§ 4 Organization of the Cross-Functional
Management System............................................................... 245
Business Policy and Functional Management................ 250
Business Policy Development............................................252
Critical Considerations for Functional Management....253
Advantages of Functional Management.......................... 254


xiv ã Contents
Chapter 15 Kaizen Costing................................................................ 257
Đ 1 Concept of Kaizen Costing...............................................257
§ 2 Two Types of Kaizen Costing.......................................... 258
§ 3 Preparing the Budget.........................................................259
§ 4 Determination of the Target Amount of Cost
Reduction.................................................................................. 262
§ 5 Kaizen Costing through “Management by
Objectives”................................................................................ 263
§ 6 Measurement and Analysis
of Kaizen Costing Variances.................................................. 266
Chapter 16 Material Handling in an Assembly Plant...................... 271
§ 1 The Parts Supply System in an Assembly Plant.............271
§ 2 A System for Supplying Parts in Sets
(the SPS, or Set Parts System).................................................271
The SPS System....................................................................271
The Rationale for SPS, and Its Benefits.............................273
§ 3 “Empty-Handed” Transportation....................................275
Rationalizing the Reception of Outsourced Parts
and the Removal of Empty Boxes......................................275
Movement of the Site Materials Handler.........................275
Area for Storing Each Parts Manufacturer’s

Empty Pallets, and Trolleys with Tractor....................275
Movement of the Parts Manufacturers’ Drivers:
Coupling Station for the Trolleys Used to Bring the
Parts in to Each of the Assembly Lines........................... 277
Chapter 17 Further Practical Study of the Kanban System............. 279
§ 1 Maximum Number of Production Kanban
to be Stored................................................................................279
§ 2 Triangular Kanban and Material Requisition
Kanban on a Press Line.......................................................... 282
The Roulette System........................................................... 283
§ 3 Control of Tools and Jigs through the
Kanban System........................................................................ 285
§ 4 JIT Delivery System Can Ease Traffic Congestion
and the Labor Shortage........................................................... 286


Contents  •  xv
JIT Will Contribute to Rationalization of Physical
Distribution......................................................................... 286
Genuine JIT System Has Prerequisite Conditions......... 287
External Environment for Physical Distribution
Should Be Rationalized...................................................... 288
Chapter 18 Smoothing Kanban Collection....................................... 291
§ 1 Obstacles to Collecting Smoothed Numbers
of Kanban..................................................................................291
§ 2 Relationship between Smoothed Collection
of Kanban and Parts Delivery............................................... 292
§ 3 Smoothing Schedule for the Timing of Kanban
Collection..................................................................................293
§ 4 Inventions of Kanban Posts at the Production Site.......295

Parts Storage Site in the Assembling Factory..................295
§ 5 Post-Office Mechanism for Outgoing Supplier
Kanban...................................................................................... 296
Chapter 19 Applying the Toyota Production System Overseas....... 299
§ 1 Conditions for Internationalizing the Japanese
Production System.................................................................. 300
§ 2 Advantages of the Japanese
Maker-Supplier Relationship..................................................301
§ 3 Reorganization of External Parts Makers in
the United States...................................................................... 302
§ 4 Solution for Geographical Problems Involving
External Transactions............................................................. 305
§ 5 External Transactions of NUMMI................................. 306
§ 6 Industrial Relations Innovations.................................... 308
Prerequisites of Flexible Labor Systems........................... 308
Prerequisites of Workplace Improvements......................310
Features of New Labor Contracts......................................310
Point 1...............................................................................310
Point 2...............................................................................312
Point 3...............................................................................312
§ 7 Conclusion..........................................................................314


xvi  •  Contents

Section 3  Quantitative Techniques
Chapter 20Sequencing Method for the Mixed-Model Assembly
Line to Realize Smoothed Production........................... 317
§ 1 Goals of Controlling the Assembly Line.........................317
Goal One: Work Load Streamlining.................................318

Goal Two and the Sequencing Model for Parts
Usage Streamlining.............................................................318
§ 2 Goal-Chasing Method: A Numerical Example............ 320
Evaluation of the Goal-Chasing Method........................ 324
§ 3 The Toyota Approach: A Simplified Algorithm............ 326
Sequence Scheduling in the Practice: An Example....... 328
§ 4 Simultaneous Achievement of Two
Simplifying Goals....................................................................329
Chapter 21 New Sequence Scheduling Method for Smoothing...... 331
§ 1 Basic Logic of Sequence Scheduling................................331
Assisting Rules.....................................................................333
§ 2 Sequence Scheduling Using Artificial Intelligence.......337
Five Patterns for Deciding the Sequence Schedule........ 340
§ 3 Diminishing Differences between Product Lead
Times......................................................................................... 342
Chapter 22 Computation of the Number of Kanban....................... 347
§ 1 Computation of the Number of Kanban....................... 347
§ 2 The Constant-Cycle Withdrawal System for
Computing the Number of Inter-Process Withdrawal
Kanban...................................................................................... 348
Numerical Example: Number of Inter-Process
Withdrawal Kanban in the Constant-Cycle System...... 349
§3 Computation of the Number of Supplier Kanban......... 354
Supplier Kanban Using the “Constant-Cycle
Withdrawal System”........................................................... 354
Computation of Supplier Kanban.................................... 354
Numerical Example for Computing the Number
of Supplier Kanban..............................................................357

Contents ã xvii
Đ 4 Constant-Quantity Withdrawal System for
Computing the Number of Inter-Process Withdrawal
Kanban.......................................................................................358
General Formula for the “Constant-Quantity
Withdrawal System”............................................................358
Numerical Example for Computing the Number
of “Inter-Process Withdrawal Kanban” Based
on the Constant-Quantity Withdrawal System..............359
Effect of Lead Time Reduction through Kaizen
Activities on the Number of Kanban............................... 360
Effect of Increasing the Capacity of Parts Boxes
Because of Smaller Parts Size............................................ 360
§ 5 Computation of the Number
of Production-Ordering Kanban...........................................361
Computation of the Number of Production Kanban
Under the “Constant-Cycle Withdrawal System”............361
Computation of the Number of Production Kanban
under the Constant-Quantity Withdrawal System....... 362
Ping-Pong Ball as a Production Kanban......................... 362
Use of Production Kanban as a Two-Bin System........... 363
Triangular Kanban of the Stamping Process................. 365
§ 6 Computation of the Re-order Point................................ 365
§ 7 Determination of Lot-Size............................................... 365
§ 8 Changes in the Number of Kanban................................ 366
Changes in the Number of Supplier Kanban.................. 367
§ 9 Maintaining the Necessary Number of Kanban.......... 368
Maximum and Minimum Numbers of the Parts
Boxes on the Indicator Plate at the Parts Shelf............... 368
Automatic System for Pushing Aside Excess Kanban..... 369

Discovery of Lost Kanban.............................................370
Chapter 23 New Developments in e-Kanban.................................... 371
§ 1 The Two Types of e-Kanban.............................................371
§ 2 Sequenced Withdrawal Method e-Kanban:
Sequenced Withdrawal of Parts Matched to the
Vehicle Loading Sequence Schedule......................................371
The Evolution of the Kanban.............................................371
e-Kanban...............................................................................372


xviii ã Contents
Đ 3 e-Kanban in the Later-Replenishment System:
e-Kanban for the Parts Needed on Engine Assembly
Lines, and So On.......................................................................374
§ 4 Sequence Information for Main, Unit, and Sub-Lines....376
§ 5 e-Kanban Passing through a Collection Center
(an Intermediate Warehouse).................................................379
Chapter 24Kanban Supporting Information Systems..................... 381
§ 1 Toyota Production System Is Supported by Many
Information Systems................................................................381
§ 2 Material Requirement Planning Subsystem.................. 382
§ 3 Kanban Master Planning Subsystem............................. 384
Internally Produced Parts................................................. 385
Externally Produced Parts................................................ 385
Material Usage.................................................................... 385
§ 4 Process-Load Planning Subsystem................................. 386
§ 5 Accounts Payable and Accounts Receivable
Subsystem via Electronic Kanban......................................... 387
§ 6 Actual Performance Measurement Subsystem............. 388

Section 4  Humanized Production Systems
Chapter 25 Cultivating the Spontaneous Kaizen Mind................... 393
§ 1 Developing the Spontaneous Kaizen Mindset:
Toward Embedding TPS..........................................................393
§ 2 How Taiichi Ohno Came to Be Daihatsu’s
Consultant................................................................................ 394
§ 3 Create a Difficult Situation and Give People a
Problem to Solve...................................................................... 394
Case 1: Mixed Assembly of the Starlet (the
Successor to the Publica) and Daihatsu’s Own
Popular Car..........................................................................395
Case 2: Development of the Ready, Set, Go! System
in the Body Welding Process............................................ 396
Case 3: “You Mustn’t Think, ‘What Am I Going to
Teach Them?’”..................................................................... 397


Contents ã xix
Đ 4 Conclusions........................................................................ 398
1. Get People to Exercise Their Ingenuity by
Creating a Difficult Situation and Giving Them a
Problem to Solve................................................................. 398
2. Never Lead People by Their Noses to the Solution
of the Problem but Always Make Them Come
Up with Their Own Improvement Strategies,
and Encourage Them to Develop Their Own
Problem-Solving Abilities................................................. 400
3. Even If Your Subordinates Fail, Do Not
Communicate a Feeling of Frustration to Them;
Lend Them a Helping Hand—Leaders Should

Become Charismatic People on Whom Others
Can Rely............................................................................... 400
Chapter 26Improvement Activities Help Reduce the Workforce
and Increase Worker Morale.......................................... 403
§ 1 Resolving the Conflict between Productivity and
Human Factors........................................................................ 403
§ 2 Improvements in Manual Operations............................ 404
§ 3 Reduction of the Workforce............................................ 406
§ 4 Improvements in Machinery............................................410
Policies in Promoting Jidoka..............................................410
§ 5 Job Improvements and Respect for Humanity..............412
Give Workers Valuable Jobs...............................................412
Keep the Lines of Communication within the
Organization Open..............................................................412
§ 6 The Suggestion System......................................................413
§ 7 Kanban and Improvement Activities..............................418
§ 8 QC Circles...........................................................................421
Structure of the QC Circle..................................................421
QC Topics and Achievements............................................421
Commendation Systems.................................................... 423
Education Systems for QC Circles.................................... 425
§ 9 New Technical Personnel System................................... 426
Labor-Management System for Toyota Shop-Floor
Technicians from 1990s Onward..................................... 426
Introduction of Technical Specialists.............................. 426


xx  •  Contents
Specialized Skills Acquisition System.............................. 427
“Get-Up-and-Go Action Program”.................................. 428

New Personnel System for Technical Personnel............ 429
The “Discussion System” Using Development
Evaluation Sheets.................................................................431
Chapter 27 Respect-for-Humanity Subsystem in the JIT
Production System.......................................................... 433
§ 1 Toward Respect for Humanity Based on Ergonomics....433
§ 2 Conventional JIT Systems for
Respect-for-Humanity Realization........................................433
§ 3 Process Improvements...................................................... 435
Facility Investments Incorporating Automation........... 435
Facility Investments Incorporating Respect for
Humanity............................................................................. 436
Worker-Compatible Machines..................................... 436
Improving Working Conditions.................................. 437
Work Strain Avoidance................................................. 437
§ 4 Need for Objective Evaluation of Workload................. 442
§ 5 Conclusion......................................................................... 443
§ 6 Appendix: TVAL Model for Measuring Workload...... 444
The Model............................................................................ 444
Applying the TVAL Model to Assembly Operations.... 446
Author’s Comment on the Model.................................... 447
Acknowledgments................................................................... 447
Chapter 28Motivational and Productivity Effects of
Autonomous Split-Lines in the Assembly Plant............ 449
§ 1 Why Can Split-Lines Enhance Morale and
Productivity?............................................................................ 449
§ 2 Problem with the Conventional Assembly Line........... 450
§ 3 Structure of the Functionally Diversified
Autonomous Line.....................................................................452
Physical Structure of Split-Lines........................................452

Personnel Structure of Split-Lines.................................... 454
Training of Line Workers and the Role
of the Foreman.................................................................... 454


Contents ã xxi
Training Corner and the Assembly Skill
Master Program...................................................................455
Đ 4 The Merits of Autonomous Split-Lines.......................... 456
Worker Motivation............................................................. 456
Productivity and Autonomy Based on Risk Spreading.... 458
Size of Buffer Stocks........................................................... 462
Line Stop Causes................................................................. 462
Unnecessary Inventory Eliminated as Waste................. 463
Chapter 29 Mini Profit Centers and the JIT System........................ 465
§ 1 Why Do MPC and JIT Systems Fit Each Other Well?...... 465
§ 2 Comparison and Mutual Extension of Merits
between JIT and MPC Systems............................................. 466
Motivating People in an MPC through the Single
Goal of Profit....................................................................... 467
Delegation of Larger and Wider Authority..................... 468
Authority for Flexible Exchange of Workers
among Various MPCs................................................... 468
Decentralized Authorities of Each MPD.................... 468
Deployment of Target Profit...............................................472
§ 3 Computation Formula for MPC Profit...........................473
§ 4 Another Type of Mini Profit Center................................475
NEC’s Line-Company.........................................................475
§ 5 Local Optimization and Global Optimization..............476
§ 6 JIT Production System as a Prerequisite for

MPC Accounting......................................................................478
MPC Accounting Is “Cash-Basis” Accounting...............478
§ 7 MPC Accounting Will Provide Motivation
to Reduce Excess Inventory....................................................479
§ 8 Conclusion......................................................................... 480
Appendix: Reinforcing the JIT System after the Disasters
of 3/11/2011, Japan............................................................ 481
Bibliography and References............................................................... 487
English Language Literature.................................................. 487
Japanese Literature.................................................................. 492



Foreword to the First Edition
The technique we call the Toyota production system was born through
our various efforts to catch up with the automotive industries of western
advanced nations after the end of World War II, without the benefit of
funds or splendid facilities.
Above all, one of our most important purposes was increased productivity and reduced costs. To achieve this purpose, we put our emphasis on
the notion of eliminating all kinds of unnecessary functions in the factories. Our approach has been to investigate one by one the causes of various
“unnecessaries” in manufacturing operations and to devise methods for
their solution, often by trial and error.
The technique of kanban as a means of just-in-time production, the idea
and method of production smoothing, autonomation (jidoka), and so on,
have all been created from such trial-and-error processes in the manufacturing sites.
Thus, since the Toyota production system has been created from actual
practices in the factories of Toyota, it has a strong feature of emphasizing
practical effects, and actual practice and implementation over theoretical
analysis. As a result, it was our observation that even in Japan it was difficult for the people of outside companies to understand our system; still
less was it possible for the foreign people to understand it.

This time, however, Professor Monden wrote this book by making good
use of his research and teaching experiences in the United States. Therefore,
we are very interested in how Professor Monden has “theorized” our practice from his academic standpoint and how he has explained it to the foreign people. At the same time, we wish to read and study this book for our
own future progress.
At no other time in history has the problem of productivity received so
much discussion. No longer is it solely an economic problem; now it presents a serious political problem in a form of trade frictions. At such a time
it would be our great pleasure if the Toyota production system we invented
could be of service to the problem of American productivity.
Although we have a slight doubt whether our just-in-time system could
be applied to the foreign countries where the business climates, industrial
relations, and many other social systems are different from ours, we firmly
xxiii


xxiv  •  Foreword to the First Edition
believe there is no significant difference among the final purposes of the
firms and people working in them.
Therefore, we hope and expect that another effective American production system will be created utilizing this book for reference.
Taiichi Ohno
Former Vice President, Toyota Motor Corporation
Former President, Japan Industrial Management Association
Former Chairman, Toyoda Spinning and Weaving Co., Ltd.