Guide: Cost Performance Index (CPI)
What It Is:
CPI is a project management metric used in the Cost Management knowledge area. It measures the efficiency of the project's utilization of financial resources. A CPI value of less than 1.0 indicates a cost overrun, while a value greater than 1.0 signifies cost efficiency.
Why it's important:
Understanding CPI is crucial for managing project costs effectively. It provides a clear snapshot of the project's financial health and can be used to forecast total project costs at completion.
How It Works:
CPI is calculated as the ratio of the earned value (EV) to the actual cost (AC). If the EV is greater than the AC, the project is under budget. If the EV is less than the AC, the project is over budget.
Exam Tips:
Remember the formula for CPI: CPI = EV / AC. Be conscious of the CPI value's implications. A question might ask about the project's cost status given a certain CPI value. Knowing how to interpret CPI can lead you to the correct answer. Always remember, CPI less than 1 means the project is over budget, and CPI greater than 1 means the project is under budget. For CPI equal to 1, the project is right on budget.
Answering Questions:
In exam questions regarding CPI, the figures for EV and AC will often be provided. Use these figures to calculate the CPI, and then judge whether the project is under budget, over budget, or right on budget based on the CPI value.