Work Instructions That Actually Train People
Most work instructions get written to be filed, not used. Training Within Industry writes them as a job breakdown instead: the important steps, the key points that make or break each one, and why each key point matters. A breakdown only proves itself when someone learns from it — so you won't read about the method here. You're the instructor. Your trainee will do exactly what you wrote, and nothing else.
What is a TWI job instruction?
A work instruction is a one-job teaching document: the important steps, the key points that make or break each step, and the reason behind each key point. Training Within Industry (TWI) calls this a job breakdown, and it sits at the heart of the TWI four-step method — prepare the worker, present the operation, try out performance, and follow up.
A breakdown is written the way a trainer would teach it, not the way an engineer would document it: three to seven major steps, no more than two key points per step, and every key point typed Safety, Quality, or Technique so it says what it protects. During World War II, TWI certified more than 1.6 million workers in over 16,500 U.S. plants — the same method this guide teaches, one wheel at a time. It is the difference between a procedure that sits in a binder and a method that gets a new operator producing safely from day one.
Settle the person before you teach the job
This is the step almost everyone skips. Someone who is nervous will nod along and miss the one detail that mattered. It takes about thirty seconds, and it decides whether your trainee asks you questions or just pretends to follow.
Put them at ease
You: “Morning. How's your day going?”
State the job
You: “We're changing a wheel. Four steps. I'll show you, then you'll show me — and you'll tell me the key points as you go.”
Find out what they know
You: “Have you changed a wheel before?”
Do the job once. Then say where each step ends.
An important step is a chunk of the job where something actually changes — the wheel goes on, the nuts go on, the nuts get tight. Knowing where one step ends and the next starts is a judgement you build by watching, not by reading a definition. So: watch the job once, then watch it again and mark each step as it finishes.
Write the sheet. Then start the shift.
Now you write it. Every step needs the key points that make or break it and the reason behind each one. Pick from the cards — but read them closely, because some are wrong in ways that look right. Then start the shift. Your trainee does exactly what the sheet says and nothing else, so anything you left out turns up in the work.
Two key points per step, no more. If everything is a key point, nothing is.
Now the sheet empties. Fill it back in.
You check back on day one, day three, day thirty. By then the breakdown should live in your head, not on paper — the sheet is a reminder, not the job. So it empties out, reasons first, because those are the hardest to hold on to. Tap any blank cell and fill it in. Whatever you miss comes back next time.
Tap a blank cell to fill it in.
That's a job instruction, start to finish.
Do the same four steps on a real job. The builder gives you a photo per step, a sheet you can print, and an Excel template you can edit.
Open the Work Instruction builder →Frequently asked
What is the difference between a work instruction and an SOP?
An SOP (standard operating procedure) describes a whole process — the steps, the roles, and the conditions. A work instruction sits one level down: exactly how one job is done, written so you could hand it to one person at one station. TWI calls the work instruction a job breakdown: important steps, key points, and reasons why.
How is a work instruction different from standard work?
Standard work records the agreed method for the whole operation — sequence, takt time, standard work-in-process. A work instruction (a job breakdown) captures the teaching: the important steps, and for each one the key points that make or break it and why. Standard work is what the operation runs on; the breakdown is what you train someone with.
How many steps should a job breakdown have?
Three to seven major steps per job. An important step is a chunk of the job where something actually changes — the wheel goes on, the nuts go on, the nuts get tight. If you have written twenty, you have cut too fine: twenty steps slow the training down without improving it, and the key points get lost among them.
Why are key points typed Safety, Quality, or Technique?
Labelling each one forces you to say what that detail protects. A safety key point prevents injury, a quality key point prevents a defect, and a technique key point makes the work easier or more repeatable. Un-typed key points become vague — "be careful" is not a key point, it is a wish.
What is the TWI four-step method?
Training Within Industry Job Instruction runs in four steps: Prepare the worker (put them at ease, state the job, find out what they already know), Present the operation (tell, show, and illustrate one important step at a time, stressing each key point and its reason), Try out performance (have them do the job while they explain the key points and reasons back to you), and Follow up (check frequently at first, then taper off). The core rule: if the learner hasn't learned, the instructor hasn't taught.
Do work instructions need photos?
Key points live where words fail — a hand position, a gap to check, a torque value. A photo per step captures the visual the trainee cannot get from text, which is why the Kaizumi work-instruction builder supports one photo per step. The breakdown itself works without photos; it works better with them.
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Founder of Kaizumi, an AI-powered Lean training platform. More about Matthew →
Updated August 8, 2026 · The job-breakdown format and the four-step method follow Training Within Industry Job Instruction (prepare, present, try out, follow up). The wheel-change job, its key points, and the consequences shown are the standard TWI-style example, presented for teaching.