The work of a Project Manager is a continuous cycle like the Deming circle:

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Plan:

Plan the work to be performed.

Delegate:

Hand out the work (packages).

Monitor:

Monitor the work packages progress related to the 6 performance targets: Benefits, Costs, Quality, Risk, Scope and Timescale.

Adjust:

Take corrective action if issues arise.

The Project Manager monitors & controls how well the project is going according to the plan.