Principles « About PRINCE2 « References
Manage by stages

The principle

A PRINCE2 project is planned, monitored and controlled stage by stage.

Management stages provide senior management with control points on important intervals throughout the project. At the end of each stage:
The project's status should be assessed
The Business Case and plans should be reviewed to ensure the project remains worthwhile
A decision should be made whether to proceed with the project

Breaking the project in a number of stages enables senior management to set up the level of control according to the business priority, the risks and the complexity of the project.
Shorter stages offer more control, longer stages reduce the required effort of the senior management.

Planning can only be done at a level of detail that is manageable and foreseeable. A lot of effort can be wasted, attempting to plan beyond an appropriate planning horizon.
A detailled plan for the short term and an outline plan for the long term is a more effective approach. PRINCE2 produces a high-level Project Plan to show the major products throughout the project and a detailled Stage Plan for the current stage.

There are a minimum of 2 stages in a PRINCE2 project: an initiation stage and a delivery stage.

Used sources

Managing Successful Projects with PRINCE2, 2009 edition