Estimating project costs is one thing. Knowing what a project will actually cost at completion — based on current efficiency, using each team member’s real cost rate — is something else entirely. That is what the Forecast (EAC) Cost KPI delivers: an intelligent projection of total personnel costs to project completion that works with reality, not with averages.
What Is Forecast (EAC) Cost?
EAC stands for Estimate at Completion. The cost variant answers the question: What will the total personnel costs for this project be, if it is completed at its current performance level?
The critical difference from the hours variant (A.5): all hours are the same length — an hour is an hour. Costs, however, depend on who completes the remaining work. One hour of a senior developer at a cost rate of €56/h is almost twice as expensive as one hour of a junior developer at €30/h. EAC Cost accounts for these differences by calculating based on the individual team members assigned to each task — not on a simplified average rate.
How Is EAC Cost Calculated?
The base formula is:
EAC Cost = Actual Cost + Remaining Cost
For each task not yet completed, the remaining cost is determined as follows:
Remaining Cost = (Remaining Hours ÷ CPI) × Cost Rate of the Assigned Team Member
Breaking down the components:
- Remaining Hours: max(Task Budget − Actual Hours, 0) — at minimum zero, never negative
- ÷ CPI: efficiency adjustment. At a CPI of 0.95, approximately 5% more hours will be needed for the remaining work
- × Cost Rate: the individual internal hourly cost rate of the assigned team member
Why not simply use EAC hours × average cost rate? Because the result would be inaccurate. If the remaining tasks are handled primarily by a more expensive senior team member, the average-rate method significantly underestimates costs. zistemo therefore uses the differentiated calculation based on individual team members.
Step-by-Step Example from the Dashboard
| Metric | Value |
|---|---|
| Actual cost to date | €2,868 |
| Calculated remaining cost (all tasks) | €3,771 |
| EAC Cost | €6,639 |
| Planned cost budget (BAC) | €6,357 |
| Deviation | +€282 (+4.4%) |
The actual costs of €2,868 break down as follows:
| Team Member | Project Hours | Cost Rate | Cost |
|---|---|---|---|
| Anna | 32 h | €25/h | €800 |
| Ben | 28 h | €38/h | €1,064 |
| Clara | 18 h | €56/h | €1,008 |
| Total | 78 h | — | €2,868 |
The remaining costs of €3,771 result from projecting all open tasks, broken down by the respective assigned team members and adjusted for the CPI of 0.95.
The result: at €6,639, EAC Cost exceeds the planned budget of €6,357 by €282 — a moderate 4.4% overrun that can be communicated and managed while there is still time to act.
What Does This Mean in Practice?
The interpretation follows a clear framework:
- EAC Cost < Cost Budget: The project will be completed more cheaply than planned. Positive for margin and future project pricing.
- EAC Cost slightly > Cost Budget (up to ~10%): A moderate overrun within normal variation. Monitor and communicate if needed.
- EAC Cost significantly > Cost Budget (>10%): Action is required. Investigate root causes: More hours than planned? More expensive team members than anticipated? Scope additions without budget adjustment?
Comparing with the hours KPI (EAC Hours, A.5) is revealing: if hours are only slightly above plan but costs are rising significantly faster, it means that the remaining work is being handled by more expensive team members than originally planned.
Three Perspectives on EAC Cost
What the Project Manager Sees
The PM can identify at task level exactly where the cost deviation originates: Is it specific tasks, particular team members, or a systemic inefficiency? They can reassign work, reprioritize, or discuss additional effort with the client — based on concrete figures, not estimates.
What C-Level Sees
The executive level gets a reliable picture of project profitability: when EAC Cost and forecast revenue (from D.2) are both known, the projected margin can be calculated. This creates planning certainty for corporate controlling and liquidity management.
What the Team Lead Sees
The team lead understands how their own cost rate and efficiency contribute to the overall forecast. This makes resource deployment transparent and provides a factual basis for conversations about task allocation and cost accountability.
Common Mistakes and Pitfalls
The most frequent mistake: all remaining hours are multiplied by an average cost rate. This creates systematic miscalculations — too low when expensive team members do more work than planned, too high when cheaper team members take on the remaining tasks.
The second mistake: ignoring the CPI or treating it as a temporary anomaly. “Efficiency will improve” is not a reliable forecast. The CPI reflects actual performance — it is the most honest signal a project sends.
A third pitfall: cost rates that are not kept up to date. When team members receive salary adjustments but their cost rates in the system remain unchanged, every cost projection becomes inaccurate.
How zistemo Delivers EAC Cost
1. Individual Cost Rates per Team Member
In zistemo, you set an individual cost rate for each person. The EAC calculation automatically applies that rate to all open tasks assigned to that person — no average rate calculations, no manual adjustments.
2. Real-Time Project Controlling with Live Dashboard
The Project Cockpit in zistemo displays EAC Cost, actual costs, cost budget, and the percentage deviation at a glance. The data updates with every new time entry — no waiting for a monthly reporting run.
3. Custom Reports and Custom SQL Queries
For deeper cost analysis, zistemo lets you build your own reports — by cost center, by team member, by task group. Custom SQL Queries allow you to define individual KPIs without any developer involvement.
zistemo USPs: Why EAC Cost Is Especially Precise Here
Real-Time Data Instead of Spreadsheet Graveyards
In organizations without an integrated system, cost projections emerge from a chain of manual steps: export time logs, insert cost rates in Excel, build the formula, send the result by email. zistemo eliminates all of that. The forecast is generated automatically, continuously, and without transcription errors.
All-in-One: Time Tracking, Costs, and Controlling in One Platform
Because time tracking and controlling are unified in zistemo, all the data that EAC Cost needs is always current and consistent. There are no data transfer gaps, no import errors, and no outdated hour exports to reconcile.
Corporate Design for All Reports and Invoices
When you share cost reports with clients or stakeholders, they carry your branding. zistemo applies your corporate design to all exports automatically — a detail that signals professionalism and consistency.
Related KPIs
- Forecast (EAC) Hours — the hours equivalent of this KPI
- Forecast Margin — how EAC Cost feeds the projected margin
Conclusion
Forecast (EAC) Cost is the financial early-warning system of project controlling. It shows whether the cost budget will hold — not on the basis of hopes, but on the basis of actual efficiency and each team member’s real cost rate.
A +4.4% overrun, as in the example project, is manageable. But it only stays manageable if it is spotted early — not at the final billing stage. That is the purpose of this KPI.
Start Using zistemo for Free
Full project cost controlling with individual cost rates, EAC forecast, and a real-time dashboard — from day one, with no configuration effort.
FAQ
Why does zistemo use individual cost rates rather than an average?
Because average rates produce systematically wrong results as soon as expensive and affordable team members are unevenly distributed across completed and remaining tasks. Individual cost rates deliver a more precise projection — that is the core of the “Rate per Staff Member” method.
What is the difference between EAC Cost (A.6) and EAC Hours (A.5)?
EAC Hours shows the projected total hours — regardless of who performs them. EAC Cost translates those hours into euros, accounting for individual cost rates. Together, both KPIs give a complete picture: hour risk and cost risk.
What happens to EAC Cost if a team member’s cost rate changes?
In zistemo, updated cost rates take effect immediately on all future calculations. Historical actual costs remain based on the rates that were valid at the time of each time entry. This keeps EAC Cost both realistic and internally consistent.
