Definition
The realized cost incurred for the work performed on an activity during a specific time period.
Simple explanation
What you actually spent for the work completed so far.
Practical Meaning [real-world Examples]
A task budgeted at $5,000 ends up costing $5,600 in labor and materials—$5,600 is the AC.
Why it matters
Enables earned value analysis; reveals cost overruns early; supports forecasting (EAC/ETC); improves financial control.
Common Mistakes
Mixing AC with committed costs; recording AC late; comparing AC to the wrong baseline; excluding internal labor; double-counting invoices.
Related Terms
Earned Value (EV), Planned Value (PV), Cost Variance (CV), Estimate at Completion (EAC), Estimate to Complete (ETC), Budget at Completion (BAC)
FAQ
Q: Is AC the same as what was invoiced?
A: Not always—AC is the cost incurred for performed work, which may differ from invoicing timing.
Q: Can AC include internal labor?
A: Yes, if your accounting system tracks it.
Q: When is AC used?
A: Continuously during execution and monitoring.
Sources & References
PMBOK® Guide – Eighth Edition, Glossary
« Back to Glossary Index