cost performance index ("cpi")
Within earned value analysis, the Cost Performance Index. Calculated as the ratio of budgeted cost of work performed (BCWP) and actual cost of work performed (ACWP). CPI = BCWP/ACWP. If this value is 1 then the project, summary task or task is exactly on budget. If the value is less than 1, then costs are over budget; greater than 1, then costs are ahead of budget. See also Cost Variance.
Ratio of work accomplished versus work cost incurred for a specified time period. The CPI is an efficiency rating for work accomplished for resources expended.