TWI - The Missing Link to Lean Production


The following article was written by Donald A. Dinero and was presented at the IIE Lean Solution Conference, and became the base for his award winning book, Training Within Industry: The Foundation of Lean.

In 1984, the International Motor Vehicle Program (IMVP) was created at MIT in order to study the techniques used in automobile production around the world. Although MIT had already been involved with this type of study, the IMVP was intended to include governments in order to receive sufficient funding so that the studies could be extremely thorough. One result of the IMVP was a book entitledThe Machine that Changed the World by James P.Womack, Daniel T. Jones, and Daniel Roos. While comparing the mass production techniques of the United States companies (especially General Motors) with the production techniques of Japanese companies (specifically Toyota), IMVP researcher John Krafcik commented that the Toyota system was "lean". That was because, in comparison, Toyota used:

  • "half the human effort in the factory, half the manufacturing space, half the investment in tools, half the engineering hours to develop a new product in half the time. Also, it requires keeping far less than half the needed inventory on site, results in many fewer defects, and produces a greater and ever growing variety of products." 1

This book gives a historical comparison between mass production and lean production and describes briefly how each of the production methods got started. Mass production was initiated by Henry Ford and copied throughout Europe. Taiichi Ohno initiated lean production at Toyota. Ohno visited Detroit often after World War II in an effort to copy the "successful" production methods. He soon came to the conclusion that Detroit's methods wouldn't work for Toyota because Detroit was making millions of parts while Toyota would be making only thousands. He recognized that his production methods must be more flexible so that he could get the most out of limited resources. In addition:

  • "Ohno needed both an extremely skilled and a highly motivated workforce. If workers failed to anticipate problems before they occurred and didn't take initiative to devise solutions, the work of the whole factory could easily come to a halt. Holding back knowledge and effort - repeatedly noted by industrial sociologists as a salient feature of all mass-production systems - would swiftly lead to disaster in Ohno's factory." 2

The reader might be led to believe that the creation of this "lean" production was possible because of the Japanese culture. Actually, its creation was dependent on many factors, not the least of which was Ohno, and occurred over an extended period of time. An interesting note, however, is that characteristics unique to the Japanese culture were not among these factors. Womack, Jones, and Roos note that the Japanese relied on teams to accomplish much of this change, but they don't detail how those teams were formed. However, the authors do say:

  • "… in the end, it is the dynamic work team that emerges as the heart of the lean factory. Building these efficient teams is not simple. First, workers need to be taught a wide variety of skills -- in fact, all the jobs in their work group so that tasks can be rotated and workers can fill in for each other. Workers then need to acquire many additional skills; simple machine repair, quality checking, housekeeping, and materials-ordering. Then they need encouragement to think actively, indeed proactively, so they can devise solutions before problems become serious." 3

In order to teach workers a "wide variety of skills", one would need a reliable method of instructing workers so that they learn a job as effectively as possible. That means the worker should be at a productive level as quickly as possible and scrap and damage to equipment and tools should be minimized. Naturally, this should all be done with a high degree of safety. Job instruction, therefore, should not be thought of as a "necessary evil", but rather should be a main component of a supervisor's skill set. Perhaps what is more difficult, however, is getting employees to "…think…proactively, so they can devise solutions before problems become serious." What is needed is a simple scheme to enable employees to analyze what they do and then quickly implement any changes they wish to make. If the intention were to make their own jobs easier, they would have the intrinsic motivation to use the method and wouldn't have to be prodded to make improvements. If the method specified that only existing resources be used, that would make the changes more attainable since funds and personnel would not have to be requested. Finally, everyone knows that getting people to work in teams is difficult because of personnel issues that always arise. How can allsupervisors be taught to handle personnel problems non-emotionally so that they accomplish their objectives, the problems do not interfere with production and the employees in question are satisfied?

How did the Japanese become successful in achieving these objectives? The basis for the Japanese's success in getting many employees quickly trained in a variety of jobs, getting employees to think proactively about their jobs, and having supervisors deal positively with personnel situations can be directly attributed to a system of training called TWI, which stands for Training Within Industry. TWI consists of three training modules: Job Instruction, Job Methods, and Job Relations. Job Instruction trains a person to perform a task as quickly as they are capable of doing it and the result is that scrap, rework, equipment and tool damage, and injury to the worker are all minimized. Job Methods training is a simple technique which instructs employees how to improve whatever they do using the existing resources available. Job Relations Training involves solving personnel problems in an analytical, non-emotional way so that one focuses on a stated objective. The ironic footnote to this is that TWI Training originated in the United States.

In the late 1930's, the US government recognized that there was going to be a large-scale war. Even if the US were not directly involved, we would be supplying our allies with a significant amount of war material. In order to do that, the productivity of our manufacturing establishment would have to be increased; it would have to occur across the country in all industries, and it would have to be done quickly. The Training Within Industries Service (TWI) "was one of the first emergency services established by the U.S. Government after the fall of France on June 22, 1940." 4 Although the Service considered several approaches, it settled on training first line supervisors in three areas. It was reasoned that first line supervisors had the most influence on production and productivity since they were in direct contact with the people who were actually making the products. The three areas of training were Job Instruction (JI), Job Methods (JM), and Job Relations (JR). JI is important because even if a person were skilled in a technique such as welding that did not mean the person knew how to teach someone how to weld. JM is important because the workers could determine the best way to do a job if they had the skill to analyze that job from a productivity viewpoint. Finally, JR is important because supervisors must have a skill in dealing with personnel problems so that they can maximize productivity. These three modules were thoroughly tested and documentation shows that they were extremely successful until the end of WW II in 1945. At that time the Service was disbanded. Although there is no documented reason for this, it has been speculated that the Service was created for the war effort and thus it should be disbanded once the war was over. In addition, its purpose was to increase productivity. Since there was no competition for the US industries, there was little concern about increasing productivity. The training continued on a private level in the United States, but the companies offering TWI training received greater acceptance in Europe than they did at home. Moreover, when General Douglas MacArthur brought TWI to Japan, that country embraced it more enthusiastically than any European country did.

Anyone who has received both TWI and Lean training can easily see how one was created from the other. For those who have not received TWI training, the following excerpts from research papers may prove enlightening.

John Shook, who started at Toyota in 1983 and co-authored Learning to See writes:

  • "I discovered them (TWI materials) in a round about way in the process of "adapting" some Toyota training materials to make them appropriate for NUMMI. When I found myself struggling with some of the concepts of a certain training program, my Japanese colleague fetched from a back-room file a yellowed, dog-eared, coffee-stained copy of the English language original training manual, just as they received it (minus the coffee stains I trust) some 30 years before. To my amazement, the program Toyota was going to great expense to "transfer" to NUMMI was exactly that which the Americans had taught the Japanese decades before." 5

The Idea Book, a Japanese book about kaisen, states that:

  • "The forerunner of the modern Japanese-style suggestion system undoubtedly originated in the West…TWI (Training Within Industries), introduced to Japanese industry in 1949 by the US occupation forces, had a major effect in expanding the suggestion system to involve all workers rather than just a handful of the elite. Job modification constituted a part of TWI and as foreman and supervisors taught workers how to perform job modification, they learned how to make changes and suggestions. Many Japanese companies introduced suggestion systems to follow up on the job modification movement begun by TWI." 6

Lean Manufacturing is based on proper training which can be attributed to JI and continual improvement which can be attributed to JM. Most importantly, however, is the contribution made by JR, which enables a democratic culture to exist and grow.

  • "In an August 1951 interview conducted as part of a survey of the effects of TWI on Japanese management by International Economic Services Ltd., a Tokyo consulting firm, Mr. Takei of the Mitsui Mining Co., the largest coal mining company in Japan at the time, said that he felt the "concept of humanism in industry" was one of the most appreciated ideas transmitted into Japan by TWI." 7

The TWI modules give companies two major benefits. First, each one teaches employees a four-step method for the technique in question. By learning a specific method, the participant leaves the training with a skill that can be used on the job immediately. Furthermore, the training is concerned only with what is within the authority of the participant. That means that the participant can use the training without getting permission or waiting for others to be trained. In addition, because these skills are basic, they are easily transferred to any other job. Although all three modules are important, JM may be the module which most directly drives change. In the JM Method, Step One defines and breaks down the job and Step Two "Questions Every Detail" of the job. Step Two may very well be where Ohno got his "Five Why's" method. Step Three develops a new method and Step Four applies the new method. Applying the method means communicating it to everyone, documenting the new method in a way that it will be accepted, and putting the method to use. This is a strong reason many Japanese companies have such a high number of improvements (not just suggestions) suggested by their employees. The JR training teaches an analytical approach to solving personnel problems. In addition, however, it emphasis concepts on how to get results through people. It emphasizes treating people as individuals, making the best use of each person's ability and telling people in advance about changes that will affect them. Using these concepts results in a highly motivated workforce that Ohno believed he required.

The second benefit of TWI is that the sessions drive a culture change from one of a Mass Production culture to one of a Lean Production culture. Each of these courses teaches and encourages employees to think, question and take appropriate action. If successfully taught, employees leave each session knowing how to improve their work and are also encouraged to do so. Again, the training they receive is limited to their scope of responsibility so that they can take initiative immediately, which initiates and encourages the change in culture.

As mentioned, TWI forms the basis of a democratic management system because it treats people as individuals, accepts that everyone has something to offer and attempts to make the best use of each employee's abilities. One reason MacArthur's staff brought it to Japan is that their objective was to rebuild Japan as a democratic (not a communist) state. The Toyota Production System, and hence Lean Manufacturing, which grew from TWI has many democratic features in it. As a result, it has been said that implementing Lean Manufacturing requires a "different' kind of thinking or a culture change in order for it to be successful. This culture change can be characterized as going from one of a "command and control" management to one of "stewardship" 8. There is a paradox here in that while Lean Manufacturing involves a very democratic form of management, many people attempt to implement Lean Manufacturing using autocratic methods. Attempts to force people to use Lean techniques will result in their ineffective use at best. Therefore, just teaching what people should do in a "lean" environment will not necessarily result in their accepting those changes. They must also have a firm understanding of why they are making these changes. For many people, learning why they must do something requires that they do it by themselves and, perhaps more importantly, for themselves.

TWI was one of the basic components of the Japanese production systems, but knowing the contents of TWI Training does not explain how they work to change an organization's culture. The key is that although TWI does not create inquisitiveness in employees, it does do much to awaken it. Historically, Americans have had a great entrepreneurial spirit. Names like Edison, Bell, Goodyear, and Eastman quickly come to mind, but there have been thousands of other lesser-known entrepreneurs who have contributed significant amounts to our nation. During the bulk of our history, most organizations, except those in the government, were very small. It was natural for employees to think, question and make suggestions. Once corporations started getting larger, they created bureaucracies and started dividing employees into "working" and "thinking" groups. This structure "strangled the human spirit, wilted faith and hope among the population and created helplessness." 9Conversely, before the advent of TWI, Japanese business culture was hierarchical, with deference being given to senior employees. As Mr. Takei alluded in the above quotation, TWI was responsible for getting people to treat employees as individuals and to make the best use of each person's abilities. Therefore, TWI created a culture change in Japanese organizations from a hierarchical, central control management to a more democratic management. Japanese industry can now be seen as a culture that is questioning and creative.

Although there is not enough information here to determine the relationship between a business culture and its society, it is likely that individuals are questioning and creative, not because of the society in which they live, but rather because of how they are treated in that society. As our world gets figuratively smaller, we now realize that all societies face similar challenges because all societies consist of people.

For example, it is now recognized that successful companies will be those which are characterized as "Learning Organizations". Arie De Gues, the head of planning for Royal/Dutch Shell, said:

  • "The ability to learn faster than your competitors may be the only sustainable competitive advantage." 8

Finally, Peter Block has written:

  • "Success in the future will depend on people who have a passion for the business, who generate new ideas, ways of doing things that result in new knowledge and that results in innovative and unique products in the marketplace." 9

Jack Welch, the former CEO of GE reflects this thought when he gives what amounts to a definition of a "learning organization."

  • "Our behavior is driven by a core fundamental belief: The desire, and the ability of an organization to continuously learn from any source -- and to rapidly convert this learning into action -- is the ultimate competitive advantage." 10

Although much has been written about learning organizations, motivating employees, and team building, a missing link may be the tool or skill that is required for the thinking process that is used in all three of these concepts. Even professionals who have been taught to question often restrict their questions to their technical expertise. Many successful processes such as GE's "Work Out" program and Lean Manufacturing techniques usually focus on what to do but do not include details on how to do it or what basic skills are required before such a program can be successful. Consequently, organizations will attempt to duplicate the "Work Out" program or will attempt to implement Lean techniques, such as 5S, e.g., and meet with only a modicum of success. The reaction then is that the program in question is "not as good as advertised." They know how to reproduce what to do, but they don't know why they're doing it.

How, then, do we change an organization's culture from one where everyone is dong what they are "supposed to be doing" to one where they question the best way to do something? The three components of TWI provide the answer. Although it will vary from company to company, the following is a brief scenario of how a culture might change.

Often, employees have many good ideas that would improve productivity, but they do not know how to implement them. When they attempt to make a suggestion, the procedure in place is cumbersome or ineffective for sustaining changes. Job Methods Training offers a simple four step analytical method for an employee to take action to make a change which makes his/her job easier. The changes are to be within the realm of the employee's responsibilities and with existing, available resources.

Once small improvements have been made on a continual basis and productivity is seen to be increasing, employees will start to cross department lines and begin working on larger problems using the same technique. Again, the employees will initiate this because they will see that it is to their benefit. Employees will begin to realize that they have control over some parts of their jobs. This happens not because they are told they are empowered, but rather because they actually are. Management does not interfere because little, if any, cost is involved and savings are very apparent. It does not take a long time for the organization's culture to change from accepting everything as is to one where employees are working together making changes for the better. The culture change has thus been started and continues because of the success created.

Job Instruction deals with the skill of communicating directions in the most efficient manner so that time, material, equipment and injury are minimized. Most people recognize that knowing how to do a task does not mean a person can teach that same task to another. Although they could be left to their own devices, employees will be performing at a competent level faster if they are trained with the JI Training Method. As a result, there will be less scrap with less damage to tools and equipment and the operations will be done more safely. Because JI is a reliable way to get employees up to productivity standards as quickly as they are able, each employee can be taught more jobs and cross-training becomes a way of life instead of a goal. Thus, as methods change through the efforts of JM and people change positions and duties, they become productive in an efficient manner. Changes are implemented more smoothly and more successfully. Although instruction may seem peripheral to the establishment of a culture, it actually determines how employees think about their jobs. Part of the JI method requires the instructor to inform the employee about the job so that the employee views it with a conscientious attitude. The mindset established here is that every job is important and critical to the company's success. Improved quality is the natural by-product.

Job Relations is important when personnel situations arise that effect production. The proper handling of such situations effects not only the individual(s) directly involved in the situation, but usually it will effect others in the organization also. Job Relations Training offers an analytical and non-emotional method to address personnel problems. Again, the JR method is simple and straightforward, but it includes concepts such as defining the objective, getting all the facts, and weighing the information before making a decision. When personnel situations become emotional, a problem may be eliminated, but the actual objective may not be accomplished. Often the failure of many teams or work groups is due to personnel problems that interfere with the objectives of the group. JR Training deals with not only how to handle personnel problems but also how to learn to anticipate problems before they begin to interfere with production.

Although some people view JM as the driving force and the most important component of TWI, the three modules are equally important and exhibit a symbiotic relationship. Job Methods may drive change, but Job Instruction and Job Relations are required to sustain and accelerate it.

The training is successful because of the following eight characteristics:

  1. The purpose of the training can be seen as a method to make the employee's job easier. It provides an intrinsic motivation to the employee, which means the employee is self-motivated to make the change. S/he does not have to be "told" to do something. They want to do it because it makes their job easier.
  2. The employees can use these methods by themselves. For JM, small, achievable changes using existing resources are targeted. For JI, the employee does the instruction. For JR, the employee handles the personnel problem and seeks additional help only if they believe the action is beyond their responsibility. As a result, successes can quickly accumulate and this has a tendency to sustain the activity.
  3. For JM, the initiator of the change must communicate the change to anyone even remotely connected with it. This improves both communication and teamwork across department lines. In JR, supervisors are taught how to confront situations, which not only leads to a faster resolution of the problem, but also enhances communication.
  4. The method learned in each module is a simple four-step technique. This means is can be easily learned and remembered.
  5. The employee breaks down each situation and the method gives him/her a way to think through all possibilities and encourages questions. Answers to these questions often give the employee a better understanding of how the organization runs and may trigger additional ideas for change.
  6. Sixth: The skill training involves "learning by doing," which has two advantages. There is no question that the participant's have learned the method because they demonstrate its use on an example of their choosing. Also, the participants receive immediate gratification by doing something that will make their job easier. The success achieved in training motivates the employee to continue making improvements after the training.
  7. The sessions are given in five two-hour periods. This allows for the participants to reflect on what they have seen that day and to ask questions the following day. This characteristic results in better learning. In addition, it is easier to break away from work for two hours at a time than it is for eight hours at a time. Thus, there is less disruption to production.
  8. The training encourages thinking because only a process is taught. Specific answers are not given. It remains for the employees to use the process and arrive at their own solutions. This is something of which most employees are capable but are not able to accomplish without the analytical tools given by the training.


There are many good training programs available, but the key concept to remember is that whomever receives training should be prepared for it. Don't teach calculus before the person knows algebra and don't teach algebra until the person understands basic arithmetic. Training such as '5S' can be valuable, but if the employees have not developed questioning attitudes and a way to solve problems, the program could dissolve within six months or a year. People want to be productive and want to have control over their jobs. The characteristics in TWI training enable employees to accomplish both of those goals. Job Methods Training forms a basis for methods improvements and Job Instruction and Job Relations Training help maintain the momentum created by Job Methods Training. Finally, if a democratic form of management is to be introduced, don't use autocratic methods to introduce it. Employees know the difference and if they hear one thing and see the other, they will be confused as to what is really required. If you are starting a Lean initiative, make sure your employees have developed and are using a questioning attitude about their work. Once this happens, they may ask you for 5S training. Given the proper tools, most employees are smart enough to solve their own problems and that is the basis for a learning organization - the ultimate competitive advantage.


1. Womack, James P, Jones, Daniel T. & Roos, Daniel. (1990) The Machine That Changed The World. New York. Harper Perennial; p 13.

2. Womack. p 53.

3. Womack, p99.

4. Robinson, Alan G. & Schroeder, Dean M. (Winter 1993) Training, Continuous Improvement, and Human Relations: The U.S. TWI Programs and the Japanese Management Style; California Management Review, Reprint Series; CMR, Volume 35, Number 2, p 37.

5. Huntzinger, Jim. (Second Quarter 2002) The Roots of Lean Training Within Industry: The Origin of Kaizen . p15. The Tribune. The Society of Manufacturing Excellence.

6. Robinson. p 51.

7. Robinson. p 52.

8. Senge, Peter…[et al], (1999) The Dance of Change: The Challenges to Sustaining Momentum in Learning Organizations. New York. Currency Doubleday. P 22.

9. Block, Peter, Stewardship, New York, Berrett-Koehler, 1993.

10. Senge, p.22.