Methodology & Terminology
Calculation basis, report scope, and interpretation.
Standards and scope
Terminology is informed by PMI earned-value guidance and AACE Recommended Practice 10S-90. XER360 is not certified or endorsed by either organization. DCMA-style checks and XER360 diagnostics are screening tools, not a PMI/AACE compliance determination or contractual acceptance decision. Project specifications and the approved controls plan govern.
Calculation basis and limitations
Baseline and progress
PV uses baseline resource budgets spread over baseline activity-calendar working hours through the current Data Date. BAC uses the same resource-cost basis. No baseline means no PV or progress ratios. Resource curves and baseline expenses are not included in PV; warnings identify these limitations.
EV is an estimate
EV uses current resource budgets weighted by activity Physical % Complete. It does not implement all P6 WBS earned-value techniques. Budget revisions and differences between current and baseline scope can affect EV/BAC. Reconcile these inputs before contractual reporting.
Costs and forecasts
AC includes the selected project's resource and expense actual costs. ETC uses current remaining costs; EAC is AC + ETC. This-period AC is current cumulative AC less previous-update cumulative AC, including cost corrections.
Curves and units
The actual-cost curve is an estimated allocation, not a ledger of period postings. Its percentage is budget spent, not Performance % Complete. Monetary values retain the XER's units; no exchange-rate conversion is performed.
Schedule review boundaries
- DCMA-style checks show screening criteria and applicable populations. The overall score is an XER360 summary, not an official DCMA or PMI score.
- A critical-path test requires recalculation in a scheduling engine. Unavailable checks are not passing checks.
- Calendar comparisons use the two files selected in Compare. Dated exceptions show the affected date; workweek rules recur and do not have one edit date. Unmatched calendars may be added, removed, or renamed.
- Active out-of-sequence findings consider relationship type, lag, actual progress, and unresolved predecessor requirements. They are not a replacement for the P6 schedule log.
- Milestone differences are calendar days. Activity duration and total float use working-day conversion settings. They are not interchangeable.
Terms and formulas
- Planned Value (PV)
- Budgeted cost of work scheduled through the status date.
- Earned Value (EV)
- Budgeted value of work performed, measured using an established earned-value technique.
- Actual Cost (AC)
- Cost incurred for work performed.
- Budget at Completion (BAC)
- Budget for the defined scope, not the forecast cost.
- Estimate to Complete (ETC)
- Forecast cost of the remaining work.
- Estimate at Completion (EAC)
- Total forecast cost: AC + ETC.
- Cost Variance (CV)
- EV - AC. A positive value is favorable.
- Schedule Variance (SV)
- EV - PV, in cost units, not a delay measured in days.
- Cost Performance Index (CPI)
- EV / AC. Below 1 indicates unfavorable cost efficiency.
- Schedule Performance Index (SPI)
- EV / PV. Below 1 indicates less earned value than planned.
- Schedule % Complete
- PV / BAC x 100. Planned progress.
- Performance % Complete
- EV / BAC x 100. Actual spending is not physical progress.
- Total Float
- Time an activity can be delayed without delaying the applicable finish or violating a schedule constraint.
- Data Date
- Schedule status date separating recorded progress from remaining work.
- Baseline
- Reference schedule selected for comparison. Uploading a file does not establish contractual approval.
- Critical Path
- A driving path that determines project duration. Low float alone does not establish the driving path.