Prior to beginning work on this discussion forum, read Chapter $13$: Progress and Performance Measurement and Evaluation from your course textbook and Chapter $6\mathrm{.}5$: Develop Schedule and Chapter $7\mathrm{.}4$: Control Costs from the book, PMBOK Guide.

The cost performance index $($CPI$)$ is a popular index. How is the CPI determined? As the project manager of your course project, how can you use the CPI? Provide a real$-$life example in your discussion post.