Estimate to complete (ETC) is the forecasted cost required to finish all authorized remaining work from the current reporting point through completion. In earned value management, ETC is the forward-looking component of the estimate at completion:
EAC = AC + ETC
In this equation, EAC is the estimate at completion and AC is cumulative actual cost. The Department of Energy project management lexicon defines ETC as the estimated cost to complete authorized work from a point in time through the end of the program, project, or task. NASA uses a similar definition in its Earned Value Management reference card.
ETC is not automatically equal to the remaining budget. Instead, it should reflect how much the remaining work is now expected to cost. That forecast may differ from the original budget because of productivity trends, schedule delays, revised labor rates, material prices, subcontractor outlooks, technical problems, or realized risks.
What Estimate to Complete Tells Management
ETC answers a practical question: From the status date forward, what will it cost to finish the authorized scope? A credible answer requires more than an earned value formula. It requires a current understanding of the remaining work, the schedule for performing it, and the resources needed to complete it.
Control account managers (CAMs) use ETC to forecast the remaining cost of their control accounts. Program controls then summarize those forecasts through the Work Breakdown Structure (WBS) and organizational structure. At the contract level, the ETC combines with actual cost to produce the contractor’s EAC.
For a broader explanation of total projected cost, see Estimate at Completion (EAC) Explained. Readers who need the underlying EVM framework can also review the complete guide to earned value management.
ETC Is a Forecast, Not a Baseline Budget
Confusion often starts when teams treat budget and forecast as interchangeable. They serve different purposes.
- Budget at Completion (BAC) is the total performance measurement budget for the authorized scope at the selected reporting level.
- Earned Value (EV) is the budgeted value of work completed.
- BAC minus EV is the budgeted value of the work remaining.
- ETC is the expected actual cost of completing that remaining work.
Therefore, BAC minus EV equals ETC only when the team expects to perform all remaining work at exactly the budgeted cost. That assumption may be reasonable on a stable control account with no known rate, schedule, or productivity changes. However, it becomes difficult to defend after significant cost variances or technical disruption.
Updating an ETC also does not automatically authorize a change to the Performance Measurement Baseline (PMB). The forecast can change while the baseline remains unchanged. Baseline revisions require the applicable change-control process and authorization. For more context on BAC, see Budget at Completion Explained.
Common Estimate to Complete Formulas
Analysts use several formulas to test an ETC. Each formula makes a different assumption about future performance. The DOE EVMS Gold Card provides a concise reference for these earned value relationships.
ETC derived from the current EAC
ETC = EAC − AC
This formula isolates the remaining forecast when an approved or reported EAC already exists. It does not explain how the EAC was developed. Therefore, analysts still need to assess the forecast’s underlying assumptions.
ETC assuming future work follows the budget
ETC = BAC − EV
This approach assumes a future cost performance index of 1.00. In other words, each remaining dollar of budget will cost one actual dollar to execute. It does not assume that past overruns disappear; actual costs already incurred remain part of the EAC.
ETC based on cumulative cost efficiency
ETC = (BAC − EV) ÷ CPI
The Cost Performance Index (CPI) equals EV divided by AC. This formula assumes that cumulative cost efficiency will continue for the remaining work. It often provides a useful independent test when the remaining work resembles the work already completed.
ETC based on cost and schedule efficiency
ETC = (BAC − EV) ÷ (CPI × SPI)
This composite formula applies both CPI and the Schedule Performance Index (SPI) to the remaining budget. It may produce a more conservative result when cost and schedule performance both affect the forecast. However, analysts should not apply it mechanically. Traditional SPI is expressed in budget terms and tends to lose predictive value as a program approaches completion.
Statistical formulas provide reference points, not automatic replacements for management judgment. A formula cannot determine whether the remaining work differs technically from completed work, whether a supplier quote has changed, or whether a late test event will extend program overhead.
How to Build a Bottom-Up ETC
A bottom-up ETC estimates the remaining work at a practical level, usually by control account, work package, element of cost, or resource category. It should connect scope, schedule, resources, rates, and risks.
- Establish the cutoff date. Align actual costs, schedule progress, earned value, and forecast data to the same reporting period. Resolve material timing differences and estimated actuals before finalizing the forecast.
- Confirm the remaining scope. Identify unfinished authorized work, including rework, open material commitments, subcontractor effort, testing, data delivery, and closeout activities.
- Use the current schedule. Review remaining activity dates, durations, logic, constraints, and forecast milestones. The ETC should follow the realistic execution plan rather than obsolete baseline dates.
- Estimate remaining resources. Determine labor hours, labor categories, material quantities, equipment, travel, other direct costs, and subcontractor costs needed for each remaining task.
- Apply current rates and assumptions. Use the applicable direct and indirect rates, escalation assumptions, calendar effects, and supplier forecasts. Document material differences from the previous forecast.
- Time-phase the forecast. Place expected costs in the periods when the work will occur. This step supports staffing plans, funding analysis, cash-flow projections, and reconciliation with the Integrated Master Schedule (IMS).
- Reconcile and challenge the result. Summarize the control account forecasts and compare the total with statistical EACs, recent performance, risk registers, staffing plans, procurement data, and contractual scope.
The treatment of management reserve, contingency, fee, and other amounts can vary by organization, reporting basis, contract, and agency. The program should follow its approved EVMS description and contract reporting instructions. It should also avoid burying generalized contingency inside labor or material forecasts.
Why the IMS Matters to ETC Development
The schedule determines when remaining resources will be needed. Therefore, a credible ETC should reconcile with the current IMS and its forecast completion dates.
For example, a three-month test delay may require more than shifting planned labor into later periods. It may extend program management, systems engineering, facilities, software support, and other time-dependent costs. It may also change escalation, subcontractor availability, or the sequence of follow-on work.
Before updating the ETC, planners and CAMs should confirm that the schedule has been statused through a consistent cutoff. The IMS status date should align with the accounting period used for actual cost and earned value reporting. Teams can use the process in How to Status an Integrated Master Schedule to maintain that alignment.
However, a resource-loaded schedule does not automatically produce a valid ETC. The schedule must contain realistic remaining logic, durations, calendars, resource assumptions, and forecast dates. Program controls should also reconcile schedule-generated costs with the EVMS cost engine and accounting system.
Fictional Program Example
Assume the fictional Falcon Ridge avionics program reports the following cumulative values at the end of June:
- BAC: $12.0 million
- EV: $4.8 million
- AC: $5.4 million
- Cumulative CPI: $4.8 million ÷ $5.4 million = 0.89
The budgeted value of the remaining work is $7.2 million. If the program assumes future work will perform exactly to budget, its ETC would equal $7.2 million. The resulting EAC would be $12.6 million because the program has already incurred a $600,000 cost variance.
However, the CAMs complete a bottom-up review and forecast the following remaining costs:
- Engineering and production labor: $4.9 million
- Material: $1.8 million
- Subcontractor effort: $1.1 million
- Other direct costs: $300,000
- Applicable indirect costs: $900,000
The bottom-up ETC is $9.0 million. Therefore:
EAC = $5.4 million AC + $9.0 million ETC = $14.4 million
The CPI-based formula produces a lower ETC of approximately $8.1 million:
($12.0 million − $4.8 million) ÷ 0.89 = approximately $8.1 million
The CAMs explain that their bottom-up forecast includes additional supplier testing and three months of extended engineering support. Those known conditions are not fully represented by cumulative CPI. As a result, the $9.0 million managerial ETC has a stronger basis, provided the schedule and supporting estimates substantiate it.
Common ETC Failure Modes
- Using BAC minus EV without testing the assumption. This calculation treats all remaining work as achievable at budgeted efficiency.
- Ignoring the current schedule. A forecast based on obsolete completion dates can omit extended labor and indirect costs.
- Leaving the ETC unchanged despite known problems. Forecasts should reflect current technical, schedule, rate, and supplier information.
- Double-counting actual costs. Teams may include invoiced costs, estimated actuals, accruals, or completed work again in the ETC.
- Excluding unfinished support work. Data items, closeout, integration support, corrective action, and remaining management effort still consume resources.
- Automatically improving future efficiency. A forecast that assumes major productivity gains needs a specific and measurable basis.
- Changing the baseline to match the forecast. An unfavorable ETC does not, by itself, justify moving budget or eliminating historical variance.
- Failing to reconcile levels. Control account ETCs, WBS totals, resource forecasts, and the contract EAC should agree or have documented reconciling items.
Contractual Requirements Versus Good Practice
ETC development is a core EVMS forecasting process, but there is no universal stand-alone ETC report that applies to every federal contract. FAR Subpart 34.2 addresses EVMS application for major acquisitions and requires monthly EVMS reports when EVMS applies. For DoD contracts, DFARS Subpart 234.2 provides DoD-specific application policy and identifies the applicable solicitation provisions and contract clauses.
The contract controls the required report content, reporting level, frequency, data item, and tailoring. Therefore, teams should review the Contract Data Requirements List, applicable Data Item Description, EVMS clauses, reporting instructions, and approved system description before treating any ETC convention as a contractual rule.
Regardless of the required delivery format, good program-controls practice calls for CAMs to review their ETCs during each reporting cycle. A more comprehensive bottom-up review may occur periodically or when material technical, schedule, rate, scope, or performance changes make the current forecast unrealistic.
Questions to Ask When Reviewing an ETC
- Does the ETC cover all authorized remaining scope?
- Does it use the same cutoff date as actual cost, earned value, and schedule status?
- Do remaining labor hours align with the current IMS dates and durations?
- Are labor, indirect, material, and subcontractor rates current?
- Does the forecast include known rework, testing, closeout, and supplier impacts?
- Are efficiency improvements supported by corrective actions rather than optimism?
- How does the resulting EAC compare with CPI-based and composite statistical forecasts?
- Are significant changes from the prior ETC explained and traceable?
- Does the forecast distinguish authorized scope from pending or proposed changes?
- Do control account forecasts reconcile with the program-level EAC?
Estimate to Complete FAQ
What is the difference between ETC and EAC?
ETC is the forecasted cost of the remaining work. EAC is the forecasted total cost and equals cumulative actual cost plus ETC.
Is ETC the same as remaining budget?
No. Remaining budget represents the budgeted value of unfinished work. ETC represents the expected actual cost of performing that work. The amounts match only when the forecast assumes future performance at budgeted efficiency.
Should ETC include past cost variances?
No. Past performance is already reflected in cumulative actual cost and earned value. However, analysts should use past trends when deciding whether similar efficiency will continue during the remaining work.
How often should an ETC be updated?
CAMs should review the forecast during the regular EVMS reporting cycle and update it when the current value no longer represents the remaining work. The cadence for formal comprehensive forecasts depends on the contract, agency instructions, and the organization’s approved EVMS procedures.
Which ETC formula is best?
No single formula is best for every program. Statistical formulas provide useful benchmarks. However, a well-supported bottom-up ETC usually provides the most actionable forecast because it reflects the specific remaining scope, schedule, resources, rates, and known risks.