4. What are the key EVM/ES metrics?

- Earned Value (EV): Also known as Budget Cost of Work Performed (BCWP), the EV can be defined as the quantification of the ‘worth’ of the work done to date.

- Planned Value (PV): Also known as Budget Cost of Work Scheduled (BCWS), the PV is the sum of the approved budget for each WBS level, i.e. action, official phase, specific contract, work package, milestone. The total PV of an action must be equal to its Budget at Completion (BAC).

- Actual Cost (AC): The AC is the executed budget for achieving the work of an ISA action. The executed budget will only be known at the end of a Work Programme year. Since most of the specific contracts are on fixed price it is not relevant to keep track on the AC before the end of a Work Programme year. For a matter of simplification, the AC is then considered as equal to the PV.

- Budget At Completion (BAC): The BAC is the sum of the budgets allocated to an action. An action BAC must always be equal to its total PV (aggregation of the official phases PV).

- Cost Variance (CV): The CV is the difference between the earned value of the work performed and the executed budget (Actual Cost). CV= EV-AC.

- Schedule Variance (SV): The SV is the difference between the earned value of the work performed and the planned value of the work scheduled. SV= EV-PV. Since PV is equal to AC, then CV=SV.

- Cost Performance Index (CPI): The CPI measures the value of the work performed over its actual cost (measure of cost efficiency). CPI= EV/AC.

- Schedule Performance Index (SPI): The SPI measures the value of the work performed over the value of the work scheduled (measure of schedule efficiency). SPI= EV/PV. Since PV is equal to AC then CPI=SPI.

- Estimate At Completion (EAC): EAC corresponds to the sum of the AC to date with an objective estimate of costs for the remaining authorised work. The objective in preparing an EAC is to provide an accurate cost projection at the completion of the action. EAC= AC + Estimate to Complete (ETC).

- Variance at Completion (VAC): The VAC gives a projection of the amount over or under the budget at completion of the project. VAC= BAC-EAC.