Earned value management (EVM) is a control method that brings together, in a single analysis, three dimensions of a project: scope (the planned work), schedule and cost. It rests on three basic quantities: planned value (PV, the budget of the work scheduled by a given date), earned value (EV, the budget of the work actually completed) and actual cost (AC, what has actually been spent).
From these three curves, variances and performance indices are computed. The schedule variance (SV = EV − PV) and the schedule performance index (SPI = EV / PV) measure whether you are ahead or behind; the cost variance (CV = EV − AC) and the cost performance index (CPI = EV / AC) measure how well the budget is being held. An index above 1 is favorable, an index below 1 signals a deviation.
The main benefit of EVM is early detection: from the very first percentages of progress, SPI and CPI trends make it possible to estimate the likely cost and end date (estimate at completion), well before the gap becomes impossible to close. The classic representation is the S-curve, compared against a frozen baseline that serves as a reference.
eyeot's Projects module computes these indicators — PV, EV, AC, SPI and CPI — with an S-curve and frozen baselines that serve as a reference for schedule and cost progress. There, EVM naturally extends Gantt planning and the critical path, and provides reliable project-control KPIs.