A project should not be considered fully complete simply because the main deliverables have been produced. Exploring the project closure process provides insight into the activities required to formally complete the project. Teams may need to confirm that outstanding issues have been addressed, finalise financial information, complete documentation, and obtain stakeholder acceptance. Closing these matters creates a clearer record of the project's final position. It also reduces the risk of unresolved responsibilities carrying into future work.
http://www.uniccm.com/project-closure-process