A postmortem (often synonymous with a structured “lessons learned”/retrospective at the end of a project) is specifically intended to identify what worked, what didn’t, and what to improve next time. It creates actionable improvements for future projects—process changes, tooling updates, training needs, better estimation approaches, risk triggers, and governance refinements. CompTIA Project+ closing-phase expectations include evaluating the project and collecting feedback, which is the exact purpose of a postmortem-style activity.

A contract review is valuable for procurement performance and compliance, but it’s narrower than overall delivery improvement. Archived documents are essential for auditability and reference, but archiving is primarily record retention; it doesn’t inherently analyze improvement opportunities unless paired with a review session. Project rewards support morale and recognition (also called out as part of closure activities), but they don’t generate systematic improvement insights.

A strong postmortem typically produces: a short list of top improvement themes, owners, due dates, and where to embed changes (templates, playbooks, onboarding, QA practices). That turns closure learning into measurable organizational improvement—exactly what the question is asking for.