Will the system work across its operating envelope, and is the plant ready to start?
A design review that repeats the consultant's conclusions is not a review. We test the package against the statement of requirements, the approved P&IDs, the operating limits, constructability, safety, maintainability and the scope interfaces. We follow the flow path across drawing sheets, not page by page. Continuation arrows, manifold layouts and battery limits are where the gaps hide.
For commissioning and restart we write the sequence the way it will be done on site. Pre-start valve lists. Isolation and reinstatement. Process and flare route checks. Shutdown valve permissives and overrides. Hold points with stop criteria. Site sign-off at each step. A planned date stays a planned date. Nothing is called commissioned until the line status, the logs and operations approval say so.
On concept studies we give one of four verdicts: approve, approve with conditions, hold, or do not approve. We list the missing items so the next revision can close them.