Project execution (or implementation) is the phase in which the plan designed in the prior phases of the project life is put into action. The purpose of project execution is to deliver the project expected results (deliverable and other direct outputs). Typically, this is the longest phase of the project management lifecycle, where most resources are applied.
During the project execution the execution team utilizes all the schedules , procedures and templates that were prepared and anticipated during prior phases. Unanticipated events and situations will inevitably be encountered, and the Project Manager and Project Team will have to deal with them as they come up.
In the standard division of project management discipline this phase is called "Project Execution and Control"; the term "control" is included here because execution is not a blind implementation of what was written in advance but a watchful process where doing things goes along with understanding what is being done, and re-doing it or doing it differently when the action does not fully correspond to what was intended. This "control" is an integral part of project management and is a necessary task of the project manager. As such it is different for project evaluation as generally conceived in aid programmes, where evaluation is usually performed by a team different from the project execution team ( e.g. the programme manager, the quality support officer, etc.), so as to independently verify the quality and the efficacy of the work done.
When the whole team is close-knit control, monitoring and evaluation move hand in hand supporting and giving added value to each other. A possible way of differentiating project control by project evaluation is to say that while "control" is done by the project manager (that include monitoring of subordinates and self evaluation) evaluation is generally done directly or through a group by the line manager of the project manager and is an activity occurring in the "shared field" between project and programme management.
The key elements of project execution is the ability of working effectively in the team and the ability of remaining faithful to project scope while facing unpredicted events and difficulties.