A plant manager told me his new hires were up to speed in two weeks. Then I sat down next to one of them.

Day nine. The work instruction was open on the screen in front of her, and she still turned around every four or five minutes to ask the operator behind her. Not because she could not read it. Because the document told her what to do, and the man behind her told her what to watch for.

Search “how to write a standard operating procedure” and you will find hundreds of guides. Almost all of them teach you how to format a document: number the sections, define the scope, list the steps, add a revision block. Useful, and completely beside the point.

The formatting was never the hard part. The hard part is that most of what makes someone competent at a job has never been said out loud, and a template does not ask for it.

Start by admitting what a procedure is for

An SOP has two jobs, and they pull in different directions.

One is to satisfy a system: audits, certification, customer requirements, traceability. That job rewards completeness and formal language.

The other is to let a competent person perform a task correctly without the expert standing next to them. That job rewards brevity, sequence, and judgment.

Most manufacturing SOPs are written for the first job and then handed to people who need the second. That is why they end up in a binder while the real training happens over somebody’s shoulder.

Write for the second job. The first one is a formatting exercise you can apply afterward.

The seven steps

1. Pick the job by where the questions land

Do not start with your most critical process. Start where the questions concentrate. Ask a supervisor which job generates the most interruptions, or ask the newest operator what she asks about most often. That is where the undocumented knowledge is densest, and where a good procedure pays back fastest.

2. Record the expert doing the work, out loud

Not an interview at a desk afterward. At the machine, while the work is happening, narrating as they go. Memory reconstructs a clean version of a job; the hands remember the real one.

Two operators is better than one. Where they diverge, you have found either an undocumented best practice or a source of variability, and both are worth knowing about.

3. Chase every “obviously”

This is the step that separates a real procedure from a checklist.

Experts skip. They have compressed a hundred small decisions into habit, and habit is invisible from the inside. When someone says “then you just bring it up to temperature,” the useful information is in the word just. How do you know it is ready? What does it look like right before it is ready? What happens if you go too far?

Every time you hear obviously, just, you’ll feel it, you can tell, stop and ask. That is tacit knowledge announcing itself.

4. Write it as the operator said it

Keep the verbs the floor uses. If they say the fixture “walks,” write that it walks. Translating shop language into engineering register does not raise the quality of the document, it lowers the odds anyone reads it.

Short sentences. One action per step. Present tense, active voice, second person.

5. Add the failure signals

Steps tell you what to do. Signals tell you when something is going wrong, which is where defects actually get prevented.

For each critical step, write down what “going wrong” looks, sounds, or feels like, and what to do about it. This is almost never in a standard SOP template, and it is the single highest-value content you can add.

6. Test it with someone who does not know the job

Hand the draft to an operator who has never run that process and watch them work through it. Do not help. Every time they hesitate, stop, or turn around to ask, mark the line.

A procedure that has not been tested this way is a hypothesis, not a standard.

7. Decide, before you publish, how it will get corrected

This is the step everyone skips, and it is the one that decides whether your work survives.

If updating the document requires a form, a review board, and a two-week cycle, the document begins dying the day you publish it. Every improvement made on the floor from that point on lives outside it. Six months later you are back to a procedure nobody follows.

Make the correction path shorter than the workaround. If it is not shorter, people will take the workaround, and they will be right to.

Why this is worth doing now

Deloitte and The Manufacturing Institute project that US manufacturing could need as many as 3.8 million new workers by 2033, and that roughly 1.9 million of those roles could go unfilled if the talent gap does not close. Meanwhile APQC’s 2025 research found that 41% of organizations rarely or never attempt to collect know-how from departing employees, and that 41% of employees have had to start a job essentially from scratch because nothing was handed over.

Put those together and you get the actual shape of the problem. A large intake of new people, arriving into processes whose real content was never written down, learning from a shrinking number of experts by standing next to them.

You cannot hire your way out of that. You can only shorten the distance between what the expert knows and what the document says.

What we do differently

The bottleneck in every method above is step two. Getting an experienced operator to narrate a job properly takes a skilled interviewer, and most plants do not have one available for a hundred procedures.

At SenseiLab we removed that bottleneck. Operators talk directly to our AI agent, in their own words, at their own pace, and the agent does the chasing: it asks the follow-up questions, it catches the “obviously,” it pushes for the failure signals. No forms, no consultant sitting there transcribing, no new software for the floor to learn. Two SOPs can be captured in parallel, so the plant is not waiting in line.

What comes out is a Smart Living SOP that keeps updating as the process changes, instead of freezing on the day we finish.

Start smaller than you think

Pick one job. The one that generates the most questions.

Sit with the operator for forty minutes and record them working through it out loud. Do nothing else. Do not format anything, do not open a template.

Then listen back and write down every place they said “obviously.” That list is the procedure you have been missing, and it is the reason your new hire is still turning around on day nine.

FAQ

How do you write a standard operating procedure for manufacturing? Start by recording an experienced operator performing the job and narrating it out loud, then chase every step they treat as obvious, write it in the language the floor uses, add the signals that tell you something is going wrong, and test the draft with someone who has never run the job. Formatting comes last.

What is the difference between an SOP and a work instruction? An SOP describes the process and its controls at a level of policy and sequence. A work instruction describes exactly how to perform a specific task at a specific station. In practice most plants need the work instruction to carry the judgment, and most templates leave it out.

How long should a manufacturing SOP be? Short enough to be used at the workstation. If following it is slower than asking a colleague, it will lose to the colleague regardless of length.

How do you capture tacit knowledge from operators? Through conversation while the work is happening, with persistent follow-up questions on everything the expert treats as self-evident. Written questionnaires and post-hoc interviews miss most of it, because experts cannot reliably recall decisions they have made automatic.

How often should SOPs be updated? As often as the process changes. That is only realistic if the correction path is shorter than the workaround, which is why the update mechanism should be decided before the procedure is published.

Diego Echenique is the founder of SenseiLab. He has spent more than twenty years in manufacturing operations across the Americas, Europe, the Middle East and Asia.