Process Performance Target Scope is a critical performance target in PRINCE2, emphasizing clear definition and control over the project's deliverables. This ensures that the project focuses on the right work and avoids unnecessary feature creep.  PRINCE2 advocates for a well-defined product breakdown structure (PBS) that outlines the project deliverables.  It also promotes effective change management processes to ensure that any proposed deviations from the scope are carefully evaluated and approved before implementation.  By maintaining a clear understanding of the project's boundaries and managing scope changes effectively, project managers can deliver the agreed-upon functionalities within budget and avoid project delays or functionality gaps that could compromise project success.