Earned Value Management Calculators

Cost Performance Index (CPI) Equations

Cost Performance Index (CPI) is the ratio of budgeted costs to actual costs (BCWP/ACWP). CPI is often used to predict the magnitude of a possible cost overrun by dividing it into the original cost estimate (original cost estimate/CPI = projected cost at completion).

A CPI greater than 1 is good (under budget)

< 1 means that the cost of completing the work is higher than planned (bad)

= 1 means that the cost of completing the work is right on plan (good)

> 1 means that the cost of completing the work is less than planned (good or sometimes bad).

Having a CPI that is very high (in some cases, very high is only 1.2) may mean that the plan was too conservative, and thus a very high number may in fact not be good, since the CPI is being measured against a poor baseline. Management or the customer may be upset with the planners since an overly conservative baseline ties up available funds for other purposes, and the baseline is also used for manpower planning.

Schedule Performance Indicators (SPI) Equations

Schedule Performance Indicator (SPI) is a measure of schedule efficiency on a project. It is the ratio of earned value (EV) to planned value (PV). A positive value (i.e. greater than 1) indicates that work is ahead of schedule. A negative value (i.e. less than 1) indicates that work is behind schedule

budgeted cost of work performed (BCWP)

Cost Variance (CV) Equations

Cost Variance (CV) is the difference between the budgeted and actual cost of work performed.

Cost Variance equals Earned Value minus Actual Cost (CV=EV-AC). If the resulting value for the cost variance is a number greater than zero (or “positive value”), then it is considered to be a favorable cost variance condition. A value that is less than zero, or a resulting “negative” value, represents a cost variance that is considered less than favorable.

Schedule Variance (SV) Equations

Schedule Variance is any difference between the projected duration for an activity and the actual duration of the activity. Also the difference between projected start and finish dates and actual or revised start and finish dates.

The difference between BCWP and BCWS, schedule variance shows how the current schedule compares with the baseline schedule (in terms of time progress. This can be shown as a numeric difference, where positive values indicate that the schedule is ahead of the baseline schedule and negative values which indicate that work is behind schedule. It can also be expressed as a percentage such as: SV(%) = (BCWP-BCWS) x 100 / BCW.

Schedule Variance at Completion (VAC) Equations

VAC (Variance at Completion) is the BAC (Budget at Completion) - EAC (Estimate at Completion, or real costs).

A project is over budget if VAC is a negative number (EAC greater than BAC) and it is under budget if VAC is positive (BAC greater than EAC).