Cost Performance Index (CPI)

Definition

The Cost Performance Index (CPI) is a key performance measurement used in project management to evaluate the cost efficiency and financial effectiveness of a project. It is calculated by dividing the earned value (EV) by the actual cost (AC), providing insights into how well the project is adhering to its budget. A CPI greater than one indicates that a project is under budget, while a CPI less than one signifies that it is over budget.

5 Must Know Facts For Your Next Test

1. CPI is calculated using the formula: $$CPI = \frac{EV}{AC}$$, where EV is the earned value and AC is the actual cost.
2. A CPI of 1 means the project is on budget; above 1 indicates cost savings, while below 1 suggests cost overruns.
3. CPI helps project managers make informed decisions regarding resource allocation and project adjustments.
4. Monitoring CPI regularly allows for early detection of financial issues, enabling timely corrective actions.
5. CPI can be used alongside other metrics, like SPI, for a comprehensive understanding of project performance.

Review Questions

• How does the Cost Performance Index (CPI) inform project managers about their project's financial health?
  • The Cost Performance Index (CPI) provides critical insights into a project's financial health by comparing the earned value against actual costs. If the CPI is greater than one, it shows that the project is spending less than planned, suggesting efficient use of resources. Conversely, a CPI below one indicates that the project is exceeding its budget, which may prompt project managers to analyze expenses and take corrective measures to realign costs with budget expectations.
• What are some potential actions a project manager might take if they discover a low CPI during project monitoring?
  • If a project manager discovers a low Cost Performance Index (CPI), indicating that costs are exceeding budgets, they may consider several actions. These could include re-evaluating resource allocation to identify inefficiencies, negotiating with vendors for better pricing, reducing scope or postponing non-critical tasks to save costs, and enhancing financial tracking processes to improve future performance. The goal would be to regain control over costs while ensuring that project objectives remain achievable.
• Evaluate the importance of using CPI in conjunction with other performance metrics like SPI for effective project management.
  • Using the Cost Performance Index (CPI) alongside other performance metrics like the Schedule Performance Index (SPI) is essential for effective project management because it provides a more comprehensive view of both cost and schedule efficiency. While CPI focuses on budget adherence, SPI assesses how well the project adheres to its timeline. Together, these metrics allow project managers to identify not just where money is being spent inefficiently but also where time may be lost. This combined analysis enables proactive decision-making to address issues holistically and maintain overall project health.

Related terms

Earned Value (EV): A measure of the work performed up to a specific point in time, expressed in terms of the budget authorized for that work.

Actual Cost (AC): The total cost incurred for the work performed on a project at a specific point in time.

Schedule Performance Index (SPI):

A measure similar to CPI but focuses on the efficiency of time management, calculated as the ratio of earned value to planned value.