Most processes on your shop floor don’t need a complicated procedure. A photo, a short video, and a clear step by step instruction gets the job done. That’s the whole idea behind a standard SOP format. Quick to create, easy to follow, and built for routine tasks.
But some processes carry more weight. If getting a step wrong could affect quality, compliance, or the customer, a basic instruction isn’t enough.
Why Documentation Alone Isn’t Enough
Most defects and quality escapes don’t happen because someone was careless. They happen because critical knowledge never made it from one person to the next.
Someone on your floor knows exactly what matters on a given task. They know what can go wrong and why certain steps have to be done a specific way. If that knowledge stays in their head, it doesn’t transfer just because you wrote down the steps.
A guide tells someone what to do. A training standard helps them understand what matters. For critical processes, you need the second one.
Standard SOP or TWI: How to Choose
Here’s the simple rule.
- For routine processes, use a standard visual SOP. Keep it simple, keep it visual.
- For processes tied to safety, quality, compliance, or customer experience, use the TWI format instead.
Routine processes are instructions.
Critical processes are training standards, and they need to be treated differently.
What TWI Actually Captures
TWI breaks a process into three parts:
- The major steps
- The key points within each step
- The reasons why those key points matter
That third piece is what most SOPs miss. Experienced operators don’t just know the steps. They know which details are critical and why.
Take torque as an example. Telling someone to torque a bolt to 45 Newton meters is an instruction. Explaining that the setting prevents joint failure under load is understanding. Once someone understands the reason behind a step, they’re far more likely to do it correctly and catch a problem before it becomes a defect.
Training Isn’t the Finish Line, Validation Is
For critical processes, showing someone the steps once isn’t enough. You need evidence they understand the process and can perform it correctly.
There’s an old auditor’s line for this: if it wasn’t documented, it didn’t happen. Harsh, but true often enough. For critical processes, competence shouldn’t be assumed. It should be demonstrated, assessed, and recorded.
That means knowing, at any point:
- Who’s been trained
- Who’s been validated
- Who’s qualified to perform the task
- When retraining is due
The Takeaway
The goal was never to produce more documents. It’s to build people who can perform critical processes safely and consistently, every time.
Documentation is the first step. Competence is the destination.