Most validation problems can be traced back to the user requirements. Requirements too vague to test. Requirements copied from a vendor brochure. Requirements that describe a feature instead of a need. By the time testing starts, it is expensive to fix any of it.
A good URS is shorter than most people expect, and much more specific.
What a requirement should say
A requirement says what the business needs the system to do, in terms someone can check. The system shall be user friendly is not a requirement. The system shall prevent a batch record being approved by the person who executed it is.
A quick test for each line: could two people read it and agree on whether the system meets it? If not, rewrite it.
Separate needs from solutions
Requirements written after a demo tend to describe the product that was demonstrated. That locks you into one vendor before you have chosen, and it makes the URS useless if you later pick something else.
Write the need, not the screen. The system shall record the reason for every result change is a need. The system shall have a drop-down for change reason is a design choice.
Mark what is GxP-relevant
Not every requirement carries the same risk. Flag which ones affect product quality, patient safety or data integrity. Those are the ones that need careful testing and traceability. The rest can be verified more lightly, or accepted on vendor evidence.
This one step does more to keep validation proportionate than anything else. It is the starting point for risk assessment and for the risk-based approach CSA describes.
Common mistakes
- Several requirements bundled into one sentence, so a test cannot pass or fail it cleanly.
- Words like should, may or ideally, which leave everyone unsure whether it is required.
- Regulatory text pasted in as a requirement, such as comply with 21 CFR Part 11, without saying what that means for this system.
- No owner, so nobody can answer questions about what a requirement means.
How long should a URS be?
Shorter than most. A URS with four hundred requirements usually has a few dozen that matter and several hundred that restate obvious behaviour, vendor features or general wishes. The long tail makes traceability expensive and hides the important lines.
A useful exercise is to read each requirement and ask what would go wrong if the system did not meet it. If the honest answer is nothing much, it probably does not belong in the URS. Keep it in a wish list or a design note instead. The requirements that remain are the ones worth testing properly.
Keep it alive
A URS written once and filed is soon out of date. When the process changes, the requirements should change, and the traceability to tests should follow. A live traceability matrix makes that practical, because you can see straight away which tests a changed requirement affects. Our live RTM is how we handle it.
Where to go next
Explore GxP Copilot for AI-native validation, TraceDraft for source-traceable clinical documentation, or book a demo to see either on your own data.