| name | pra-earned-value |
| description | Measure project cost/schedule performance and forecast final outcomes with Earned Value Management using the PRA package. Use when a user provides a budget (BAC), a planned schedule curve, and actual costs/progress and wants SPI, CPI, variances, or an Estimate at Completion (EAC).
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When to use
The user has a Budget at Completion, a cumulative planned-value curve, current
progress, and actual costs, and wants performance indices or forecasts.
MCP tool
evm_analysis_tool(bac, schedule_json, time_period, actual_per_complete, actual_costs_json, cumulative) runs the complete ANSI/EIA-748 suite in one
call — do not chain the individual metrics manually.
bac: Budget at Completion (total planned budget).schedule_json: JSON array of cumulative planned completion fractions, e.g.
[0.1, 0.2, 0.4, 0.7, 1.0].time_period: current period (1-based index into the schedule).actual_per_complete: actual percent complete as a decimal (e.g. 0.35).actual_costs_json: JSON array of actual costs per period, e.g.
[10000, 22000, 37000].cumulative: "true" if the costs are already cumulative, else "false".
What it returns
- Baseline: PV = BAC × planned%, EV = BAC × actual%, AC.
- Variances: SV = EV − PV (schedule), CV = EV − AC (cost).
- Indices: SPI = EV / PV, CPI = EV / AC (>1 is favorable).
- Forecasts (EAC):
- Typical (CPI-based):
BAC / CPI — current trend continues.
- Atypical:
AC + (BAC − EV) — current variance is a one-off.
- Combined:
AC + (BAC − EV) / (CPI × SPI) — schedule pressure affects cost.
- ETC = EAC − AC, VAC = BAC − EAC, TCPI = efficiency required on
remaining work to hit the target.
Warning thresholds
- CPI or SPI below ~0.9 signals a project in trouble.
- CPI rarely improves by more than ~10% after a project is 20% complete.
- TCPI substantially above 1.0 is an unrealistic recovery target.
References
- ANSI/EIA-748 Earned Value Management Systems standard.
- DOE EVMS Interpretation Handbook (EVMSIH v2.0).
