The best indicator of whether a PIR performed by the PMO was effective is whether project outcomes have been realized. Project outcomes are the benefits or value that a project delivers to its stakeholders, such as improved efficiency, quality, customer satisfaction, or revenue. A PIR should evaluate whether project outcomes have been achieved in accordance with project objectives, scope, budget, and schedule. The other options are not as good as project outcomes in determining the effectiveness of a PIR. Lessons learned are valuable inputs for improving future projects, but they do not measure whether project outcomes have been realized. Management approval of the PIR report is a sign of acceptance and support for the PIR findings and recommendations, but it does not reflect whether project outcomes have been achieved. The review performed by an external provider is a way of ensuring objectivity and independence for the PIR, but it does not guarantee whether project outcomes have been realized. References: CISA Review Manual (Digital Version), Chapter 3, Section 3.3