In short
A deviation is any departure from what was approved. Handling one means containing the affected product, finding out what happened, deciding what to do with it, removing the cause, and checking that the fix worked. Small makers often skip all this: they fix the batch and move on, and then it happens again. A short written process is enough, and ISO 22716 treats deviations and out-of-specification products as part of good manufacturing practice.
What you will learn
- Run a deviation from containment to closure
- Find a root cause using a simple method
- Separate correction from corrective and preventive action
Before this lesson: Specifications and Release Testing
The sequence
- Detect and record. What was seen, when and by whom. Don't interpret yet.
- Contain. Mark and separate the batch. Trace where it went, using your traceability.
- Assess the risk. Could anybody be harmed? Has it left your control? If so, get qualified advice quickly. See the recall guide and the adverse events guide.
- Investigate. Find the root cause, and look for similar batches.
- Decide on the batch. Release, rework under an approved method, or reject, with reasons.
- Correct and prevent. Change what allowed it to happen.
- Verify. Check later that the action worked.
- Close. A named person signs it off, with a date.
Finding the root cause
The "five whys" method is simple, and it often helps. Keep asking why until you reach something you can change. A worked example, invented for this lesson:
- Why did the batch smell off? Because line 7 had the wrong material.
- Why was it wrong? Because Material A was weighed instead of Material B.
- Why? Because the two look alike and sit next to each other.
- Why did nobody notice? Because the batch record shows only names, and there's no check of the bottle's code against it.
- Why not? Because the record was never designed with a check step.
"Human error" would have stopped the inquiry at the second step. The last answer is something you can change. There may be several contributing causes, so keep your mind open. Avoid blaming a person when the process made the mistake easy.
Three kinds of action
| Type | Purpose | Example |
|---|---|---|
| Correction | Fixes this instance | Reject the batch; remake it correctly |
| Corrective action | Removes the cause | Add lot and code check to the record; separate lookalike bottles |
| Preventive action | Prevents a similar problem elsewhere | Review storage and labels for all similar materials |
Deciding on the batch
| Question | If unsure |
|---|---|
| Does it change the formula you assessed? | Treat it as a different formula; ask the assessor |
| Could any restriction or allergen statement now be wrong? | Recalculate; do not release until done |
| Does it still meet specification? | A pass after an error doesn't remove the deviation |
| Is reworking approved? | Don't rework without a method and a record |
| Is there an unknown? | Hold or reject. Not knowing what's in a batch is a reason for rejection |
A cost argument isn't a safety argument. Never blend a doubtful batch into a good one to hide it. If you do a stated, approved rework, it needs a record.
Trends
Keep a short log of all deviations, however small. After a dozen, patterns appear: a supplier, a step or a material. Review it every few months, and act on the top issue. Your complaints log belongs beside it. A sole maker can do this. You'll just have to play both roles, so wait a day before you close your own investigation.
A sample record
Number and date. Product, batch, what was approved, what happened. Who found it. Containment and where product went. Risk assessment and who was consulted. Root cause and evidence. Batch decision and reason. Correction, corrective action and preventive action, each with owner and date. Check of effectiveness, with date. Closure, with name.
Practical exercise: Write up one real or simulated deviation
- Choose a real batch problem from your own work. If you have none, simulate one, marked clearly as such: a wrong line, a short weighing or a mislabeled stock.
- Write a full deviation record using the form above.
- Use the five whys, and write at least three answers.
- Make the batch decision, using the questions table.
- Change your process, then test the change in a small drill later on.
You have done this well if your root cause doesn't stop at "human error", your preventive action changes a process, and you've set a date for checking whether it worked.
Common mistakes
- Fixing and forgetting. It will recur.
- Blaming a person. Ask why it was possible.
- Blending a doubtful batch away. Don't.
Key terms
- Deviation
- Any departure from an approved formula, method or specification.
- Root cause
- The underlying reason a problem occurred, which if removed would prevent it from happening again.
- CAPA
- Corrective and preventive action: steps to remove the cause of a problem that has occurred, and to prevent a similar one.
Knowledge check
Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.