What do you do when a critical deviation is performed?

We asked a vendor to go through the whole validation activities for a computer system. We already signed the PQ report but suddenly found a significant function A was not validated. Shall we raise a deviation now, update the documents and re-execute the OQ? Or shall we keep signing the validation report and raise a change control to validate function A?

It confused me a lot, signing the validation report means all the validation results meet the expectation, but it’s not true. If raising a deviation form, how to record it? deviation from the URS? If the OQ testing scripts were insufficient, can we call it as deviation?

It will be appreciated if you can provide me some guidance.

Be specific! What was the critical deviation? In any case you will have to perform a documented investigation under CAPA.