PRINCE2 mandates the use of management stages in project management. These stages are critical control points used by the Project Board to review progress, assess risks, and make decisions about the project's future. This structure allows for regular monitoring and controlling of the project by breaking it down into manageable sections. References: PRINCE2 Foundation official documentation and study materials.

The Project Board should refer to corporate or programme management for decisions when it is forecast that the project level tolerance will be exceeded. This scenario typically triggers an exception process as the predefined tolerances are fundamental limits within which the Project Board allows the Project Manager to manage the project. References: PRINCE2 Foundation official study guide and materials.

PRINCE2 sets minimum requirements within its themes. Themes support the principles and are aspects of project management that must be addressed continually and in parallel throughout the project. The themes provide knowledge areas necessary for the effective management of a project. References: PRINCE2 Foundation Handbook, Themes section.

As part of the recommended risk management procedure in PRINCE2, it is essential to regularly review risk management practices to ensure their effectiveness. This involves evaluating how risks are identified, assessed, and controlled throughout the project lifecycle. References: PRINCE2 Foundation Handbook, Risk Management section.

Setting tolerances for the three levels of plan (project, stage, and team) in PRINCE2 applies the principle of
'manage by exception'. This principle enables efficient use of management time by focusing on deviations from the plan only if they exceed predefined tolerances, rather than managing every small detail. References:
PRINCE2 Foundation Handbook, Manage by Exception section.