Cost performance index (CPI)

The cost performance index (CPI) is a measure of the financial effectiveness and efficiency of a project. It represents the amount of completed work for every unit of cost spent.

As a ratio it is calculated by dividing the budgeted cost of work completed, or earned value, by the actual cost of the work performed.

For example, if a project has a earned value (EV) of £20,000 but actual costs (AC) were £12,000:

CPI = EV / AC = 20,000 / 12,000 = 1.66

If the ratio has a value higher than 1 then it indicates the project is performing well against the budget. A CPI of 1 means that the project is performing on budget. A CPI of less than 1 means that the project is over budget.

[edit] Related articles on Designing Buildings Wiki

• Cash flow.
• Compound Annual Growth Rate (CAGR).
• Benchmarking.
• Earned value.
• Gross value added (GVA).
• Key performance indicators KPI.
• Internal rate of return.
• Net Present Value.
• Residual value.
• Schedule performance index (SPI).
• Yield.