The three TWI programmes
- Job Instruction (JI): a four-step method for teaching a task: prepare the worker, present the operation, try out performance, follow up. Each task is first broken down into important steps, key points and reasons on a job breakdown sheet.
- Job Methods (JM): a four-step method for improving a task: break it down, question every detail, develop the new method, apply it. It is an early form of kaizen.
- Job Relations (JR): a four-step method for handling people problems: get the facts, weigh and decide, take action, check results, built on foundations for good relations such as telling people how they are doing.
A fourth programme, Job Safety (JS), was added later in Japan.
Why TWI matters in lean
Toyota kept TWI after the occupation ended, and Job Instruction became the way standard work is taught: the job breakdown sheet is the training version of the standard. TWI's structured, repeatable methods are why standard work can be transferred between people and shifts without the variation that creeps in through informal training.
Using TWI today
- Job Instruction for onboarding, cross-training and re-training after a standard changes, with the job breakdown sheet as the checklist and the trainee's demonstration as the competency assessment.
- Job Methods for frontline improvement where a full A3 is too heavy.
- Job Relations for team leader development, because most frontline problems are people problems first.
TWI and the skills matrix
Each Job Instruction session ends with a demonstration; recording the result against the task in the skills matrix is what turns training into verified competence. A changed standard means a new job breakdown and re-instruction for everyone signed off against the old one.
Common mistakes
- Treating Job Instruction as a one-off course rather than the daily way of teaching.
- Skipping the job breakdown, so trainers teach from memory.
- No follow-up step, so the trainee's early mistakes become habits.