Glossary · Verification and validation
Validation plan
In functional safety, a validation plan is a documented plan defining validation methods, responsibilities, test conditions, criteria, and evidence. It is written before validation starts so that results can be judged against predefined expectations.
- Verification
- Technical documentation
In one sentence
A validation plan fixes methods, responsibilities, test conditions, criteria and evidence before validation starts.
Example
The validation plan for a CNC machining center lists each safety function, the analysis and test method, the test equipment, the pass criteria, the responsible engineer and where the records will be stored.
How it applies
- Functional safety: ISO 13849-2 expects validation to follow a plan. The plan identifies the safety functions, their requirements and the documents used as input.
- Verification: Define acceptance criteria for each check in advance. Setting criteria after seeing results undermines the evidence.
- Technical documentation: Treat the plan as a controlled document with version and approval. Changes to the design after approval should trigger a plan review.
- Evidence: The plan is the index of the future evidence package. Each planned item should link to its result, so that gaps are visible at a glance.
Validation plan vs. test plan
A test plan covers tests. A validation plan also covers analysis, reviews, independence, responsibilities and how the overall conclusion will be reached. Tests are only one method of validation.