According to the 'continued business justification' principle, when is a justifiable reason for a project...

According to the 'continued business justification' principle in PRINCE2®, a justifiable reason for a project is required before any work to start the project begins. This ensures that projects are initiated only when there is a clear business need, aligned with organizational objectives, and there is an expectation of value creation. The business case is developed during the initial stages of the project and is maintained and reviewed throughout the project lifecycle.References: PRINCE2® Foundation Manual