A commissioning deficiency log is a structured record of problems discovered during inspections, functional testing, or system verification. Entries may include the affected room or equipment, description of the issue, responsible party, priority, corrective action, status, and date of verification.

A centralized log helps prevent deficiencies from being overlooked or repeatedly reported through disconnected communication channels. It also provides project managers and ownership teams with visibility into unresolved problems that may affect acceptance or operational readiness.