What is the difference between "Turnover" and "Completions Management"?

First a few definitions:

Project management

The process of leading the work of a team to achieve all project goals within the given constraints (like Schedule and budget)

Project Turnover Management

The official process of handing over a well defined and documented scope of work from Construction (EPCM Contractor) to Commissioning (Client's Operations Team)

Project Completions Management

The process of Tracking, organising and recording of the state of “completeness” to a pre-defined criteria set by clients and projects in order to meet regulations and standards.

Commissioning

The process of assuring that all systems and components of a building or industrial plant are designed, installed, tested, and ready for operation, according to the operational requirements of the owner or final client. (Mostly done or organised by the Client)

Now, what was the difference again?

Most of the time Turnover and Completions Management are done by the same department.

"Turnover" documents the official handover to the Client.

-> MC (Mechanical Completion)

This is done on a PROJECT MANAGEMENT level.

"Completions Management" assures that all the criteria regarding design, testing and Quality are met to make sure the client can sign for MC and start safely with Commissioning.

-> Ready for Commissioning

This is done on a OPERATIONAL level.

As one can see These to terms go generally hand in hand and involves a lot of communication and collaboration Between all project stakeholders...