Cost management involves planning, estimating, budgeting, and controlling costs. Earned Value Analysis (EVA) is the most powerful technique for measuring project performance against both schedule and budget simultaneously.
Cost Estimation Techniques
| Technique | Accuracy | When Used |
| Analogous estimating | Low (±25–50%) | Early stages; based on similar past projects |
| Parametric estimating | Medium (±10–25%) | Statistical relationship between variables (e.g. cost/unit) |
| Bottom-up estimating | High (±5–10%) | Detailed WBS available; sum of individual work packages |
| Three-point (PERT) | High | Uncertainty in estimates; uses optimistic/likely/pessimistic |
Earned Value Analysis (EVA) — Key Terms
| Term | Definition |
| PV (Planned Value) | Budgeted cost of work scheduled (BCWS) — what was planned to be spent by now |
| EV (Earned Value) | Budgeted cost of work performed (BCWP) — the value of work actually done |
| AC (Actual Cost) | Actual cost of work performed (ACWP) — what was actually spent |
| BAC | Budget at Completion — total approved project budget |
EVA Performance Metrics
CV = EV − AC (Cost Variance; negative = over budget)
SV = EV − PV (Schedule Variance; negative = behind schedule)
CPI = EV / AC (Cost Performance Index; <1 = over budget)
SPI = EV / PV (Schedule Performance Index; <1 = behind schedule)
EAC = BAC / CPI (Estimate at Completion — typical forecast)
ETC = EAC − AC (Estimate to Complete)
VAC = BAC − EAC (Variance at Completion)
Types of Project Costs
| Cost Type | Description |
| Direct costs | Directly attributable to project (labour, materials, equipment) |
| Indirect costs | Overhead shared among projects (rent, utilities, admin) |
| Fixed costs | Do not vary with output (equipment hire, permits) |
| Variable costs | Vary with work output (materials consumed, hourly labour) |
| Sunk costs | Past expenditure that cannot be recovered — irrelevant to future decisions |
| Contingency reserve | Budget for known unknowns (identified risks) |
| Management reserve | Budget for unknown unknowns (unforeseeable risks) |
ESE Tip: CPI = EV/AC; <1 means over budget. SPI = EV/PV; <1 means behind schedule. EAC = BAC/CPI is the standard forecast formula. CV and SV negative = bad. Sunk costs should not influence future decisions.