Definition
Job Methods (JM) is a structured four-step method for improving how work is done. It teaches supervisors and workers to question every detail of a job — asking why each step is necessary, what its purpose is, where it should be done, when, and by whom — and then to develop an improved method by eliminating, combining, rearranging, and simplifying steps. JM is the second of the three core TWI programs, alongside Job Instruction and Job Relations.
Japanese Origin
The Japanese title kaizen no shikata (改善の仕方) means “how to improve” — connecting the TWI method directly to the broader concept of kaizen. This is not coincidental: the TWI Job Methods program was one of the structured improvement approaches available to Japanese industry in the early postwar period and contributed to the development of the systematic improvement culture that became characteristic of Toyota and other Japanese manufacturers.
History
Like Job Instruction, Job Methods was developed by the U.S. War Manpower Commission during World War II and transferred to Japan during the occupation. The method draws on the principles of industrial engineering — motion study, methods analysis, and work simplification — but packages them in a format that supervisors and workers can apply without being industrial engineers.
At Toyota, JM’s four-step approach — break down the job, question every detail, develop the new method, apply it — became part of the foundation for how improvement is conducted on the shop floor. While Toyota developed its own more sophisticated methods over time (including A3, PDCA, and TBP), the basic JM discipline of systematic questioning and structured improvement remains embedded in the company’s approach.
Steps/Process
Step 1 — Break down the job:
- List every detail of the current method exactly as it is done now
- Include every operation, every transport, every inspection, every delay, every storage
- Document quantities, distances, and times where relevant
- Do not improve yet — just record the current state accurately
Step 2 — Question every detail: For each detail, ask:
- Why is it necessary? (If not necessary, eliminate it)
- What is its purpose? (Is there a better way to achieve it?)
- Where should it be done? (Can it be done at a better location?)
- When should it be done? (Can the sequence be changed?)
- Who is best qualified to do it? (Should someone else perform it?)
- How is the best way to do it? (Can the method be simplified?)
Step 3 — Develop the new method:
- Eliminate unnecessary details
- Combine details when practical
- Rearrange for better sequence
- Simplify remaining details to make them easier and safer
Work out the new method with the people involved — get their ideas and suggestions. Write up the proposed new method.
Step 4 — Apply the new method:
- Sell the new method to those who will use it (boss, operators, related departments)
- Put the new method to work
- Give credit to those who helped develop it
- Check results against expectations
Common Mistakes
Jumping to solutions without completing the breakdown. The power of JM is in the systematic questioning of every detail. Skipping or rushing the breakdown step means improvements are based on assumptions rather than thorough analysis.
Questioning only the obvious problems. JM requires questioning every detail, including steps that seem necessary. The most significant improvements often come from eliminating steps that everyone assumed were required but are not.
Developing improvements in isolation. Step 3 explicitly calls for working with the people who do the job. Improvements developed without operator input are often impractical and face resistance during implementation.
Not following up on results. Applying the new method (Step 4) includes checking whether the improvement actually delivered the expected results. Without this check, the improvement cycle is incomplete and learning does not occur.