M3.5 — Cost Forecasting & Commercial/Contract Interfaces

M3.5 — Cost Forecasting & Commercial/Contract Interfaces

1. Practical outcome

By the end of this section, the learner should be able to produce and challenge a credible cost forecast that explains what the project or package is now expected to cost, why that expectation differs from the authorised baseline or prior forecast, what commercial and delivery assumptions the forecast depends on, and where material uncertainty remains. They should be able to build Estimate to Complete (ETC) from the remaining scope rather than simply extrapolating spend; combine incurred cost and ETC into Estimate at Completion (EAC); reconcile commitments without double counting them; assess uncommitted work, changes, claims, remeasurement, escalation, currency, productivity and schedule effects; and translate contract information into a realistic project-cost outlook.

The objective is not to make the forecast equal the budget or management target. A forecast is a current prediction based on evidence and explicit assumptions. It should move when the evidence changes, retain the history of why it moved, and remain sufficiently transparent that another competent practitioner can reconstruct the reasoning. A forecast that is deliberately held at an approved number despite contrary evidence is not control; it is aspiration presented as fact.

M3.5 completes the Module 3 cost-control journey. M3.1 develops the estimate, M3.2 establishes the authorised cost baseline, M3.3 establishes the reliable current incurred and committed position, M3.4 explains variance and corrective response, and M3.5 turns all of that evidence into the forward-looking cost expectation while integrating the commercial and contract conditions that can change the final outcome.

A useful question throughout this Knowledge Area is: “If we had to complete the remaining authorised scope from today, under the commercial conditions and delivery assumptions we now understand, what would it realistically cost — and what could still move that answer?”

2. Core concepts

A forecast is a prediction, not a target or a rewritten baseline

The cost baseline is the authorised reference against which performance is controlled. The forecast is the current best estimate of the outcome. A target may describe what management wants to achieve after intervention. These three numbers can be identical, but they answer different questions and should never be forced to agree merely for presentation.

If the authorised package total is 3.800m CU, the evidence-based forecast is 3.920m CU and management has set a recovery target of 3.850m CU, all three should remain visible. The 3.920m CU forecast should only reduce when the underlying assumptions, quantities, rates, productivity, commercial exposure or risk evidence justify the change. Recording 3.850m CU simply because it is the target hides the amount of recovery still required.

ETC and EAC are the core forecast building blocks

Estimate to Complete (ETC) is the expected cost of the remaining work from the forecast cut-off to completion. Estimate at Completion (EAC) combines the reliable cost incurred to date with the ETC. At its simplest:

EAC = incurred cost to date + ETC

The arithmetic is simple; the professional work is in establishing a credible ETC. The ETC should reflect the remaining authorised scope, current quantities, delivery method, productivity, resource plan, supplier/commercial position, schedule, risks, opportunities and unresolved interfaces. It is therefore a forecast of remaining work, not merely “budget remaining”.

The forecast must have a defined cut-off, scope and price basis

A forecast is only reproducible if its basis is clear. The practitioner should state the reporting cut-off, authorised scope boundary, WBS/CBS/control account, currency and price basis, treatment of tax where relevant, escalation assumptions, approved changes, pending changes, risk treatment and the date to which commercial information has been assessed. A forecast compiled from sources with different cut-offs can appear precise while containing hidden timing gaps or double counting.

Bottom-up remaining-work forecasting is the preferred anchor where scope is sufficiently mature

Where the remaining scope can be described, ETC should be rebuilt from the work still required: remaining quantities multiplied by realistic unit rates, remaining labour hours using achievable productivity, supplier balances adjusted for expected final quantities and changes, remaining indirect resources linked to the schedule, and identified close-out costs. This is often more reliable than applying a simple percentage to the original budget or extending the historical burn rate without considering what remains.

Bottom-up does not mean false detail. Early or uncertain work may still need analogous, parametric or allowance-based forecasting. The method should match the maturity of the remaining scope and should be explicit enough that management understands where confidence is high and where judgement dominates.

Commitment is evidence of future cost, but it is not automatically the final cost

A purchase order or contract commitment can strongly inform the ETC, but the committed value may not equal the final cost. Some commitment may already have been incurred, some may relate to optional quantities, and some contracts will change through remeasurement, indexation, provisional sums, change, claims, incentives, pain/gain mechanisms, taxes or final-account settlement. Conversely, a commitment cap may exclude work that the project still has to procure.

The practitioner should reconcile each material commitment into three questions: what part has already been incurred; what part remains valid for the remaining authorised scope; and what additional exposure or saving is reasonably expected beyond the currently approved commitment? This prevents both double counting and false comfort from nominal contract values.

Contract form changes the forecasting logic

Different commercial arrangements expose the project to different forecast drivers. The underlying cost-control principles stay the same, but the ETC method should reflect how the contract converts delivery events into project cost.

Commercial exposure is broader than approved contract change

At a reporting date the project may have supplier notifications, requests for compensation, disputed change, remeasurement, instructed work awaiting valuation, provisional sums, price-adjustment mechanisms or unresolved final-account items. Treating all of these as either zero or 100% of the supplier submission is usually poor forecasting.

The forecast should use the best current assessment allowed by organisational policy, supported by entitlement, scope, quantity, rate, schedule and negotiation evidence. The commercial register should preserve the supplier position, the project assessment, approved amount, forecast exposure and uncertainty separately. This allows the project to be realistic without prejudicing negotiation or implying that a forecast allowance is an admission of contractual liability.

Claims and change require probability and value judgement, not binary thinking

A supplier may submit a 0.180m CU claim while the project commercial team assesses that only part of the entitlement is credible. Forecasting zero until settlement can understate the outcome; forecasting the full submission can overstate it. The project should apply its approved commercial-risk methodology to estimate a defensible exposure and update it as entitlement, causation, records and negotiation evolve.

Likewise, known client-directed work may need forecast recognition before the baseline is formally changed, depending on governance. The forecast can acknowledge likely cost while the baseline remains unchanged until authorisation. This preserves the distinction between “what we now expect to spend” and “what is currently authorised as the control reference”.

Remaining quantities and productivity often matter more than historic spend rate

Forecasting by simply continuing the average monthly spend can be badly misleading. The remaining work may have a different quantity profile, learning curve, access condition, crew mix, testing burden or supplier sequence. A package that spent slowly during design may accelerate sharply during installation; a package that overspent during mobilisation may improve after learning. The ETC should therefore be driven by the physical and commercial basis of the remaining work.

Where productivity is material, forecast the remaining output and realistic productivity explicitly. If 600 technology points remain and the demonstrated sustainable rate is 18 points per crew-day, a forecast based on the original 20-point assumption needs evidence that the improvement can actually be achieved.

Schedule and cost forecasts are connected

Delay can extend project management, supervision, temporary facilities, hire, security, insurance and other time-dependent costs. Acceleration can add overtime, premium shifts, expediting or inefficient resource stacking. Resequencing can either improve or damage productivity. The cost forecast should therefore use the current credible schedule rather than the baseline dates as if they were still expected to occur.

This is an interface, not a duplication of M2.5 or M5.4. M3.5 asks what the schedule outcome means for cost; M2.5 develops schedule forecasting and scenario analysis; M5.4 integrates broader predictive analysis across disciplines.

Escalation, indexation and currency should follow expected timing

Where future costs are exposed to inflation, contractual indices or foreign exchange, the forecast should apply assumptions to the periods in which the relevant cost is expected to occur. Moving work later can change cost even when quantity is unchanged. The practitioner should state the source and date of rates or indices, distinguish hedged and unhedged exposure, and avoid mixing current-price and out-turn-price values without reconciliation.

Risk, opportunity, contingency and forecast are related but not interchangeable

The forecast should reflect credible future exposure, but the treatment of risk and contingency must follow governance. Some organisations include expected risk allowances in ETC; others show a deterministic working forecast plus a separate risk-adjusted view. Whichever convention is used, the forecast should not count the same uncertainty both in package ETC and again in contingency or quantitative risk analysis.

An approved contingency balance is not automatically subtracted from EAC. Contingency is a controlled provision or funding mechanism. The forecast describes expected cost. If a qualifying risk materialises, the cost may enter the forecast before or alongside the formal contingency drawdown; the governance transaction should remain separate from the economic prediction.

A point forecast needs an explanation of confidence

A single EAC is useful for aggregation and decision-making, but it can create false precision. The practitioner should identify the assumptions most capable of moving the number, the maturity of uncommitted scope, the status of major claims or changes, remaining schedule exposure and the difference between current working forecast and plausible alternative scenarios.

This does not require M3.5 to become a full probabilistic cost-risk analysis. M4.3 addresses quantitative risk analysis. M3.5 should, however, prevent management from interpreting 3.920m CU as if the final account were known to the last thousandth when material commercial and delivery uncertainty remains.

Cost forecast, cash forecast and funding forecast are different views

The cost forecast recognises when economic cost is expected to be incurred. The cash forecast predicts when payments will occur. Funding forecasts may reflect authorised funding availability or treasury rules. Retention, milestone payments, advance payments, invoice timing and payment terms can make these curves differ materially. A good project-controls system reconciles them but does not collapse them into one number.

Forecast movement is itself a control signal

Management should compare the current EAC with both the authorised baseline and the prior forecast. The first comparison shows the current expected overrun or underrun; the second shows what new information or changed judgement entered this reporting cycle. Repeated adverse forecast movement is often more important than the absolute variance because it suggests that the project is learning about cost too late or that corrective actions are ineffective.

A forecast bridge should explain the movement through identifiable drivers — for example recognised rework, revised productivity, new commercial exposure, schedule extension, escalation, approved change or credible opportunity. Unexplained “management adjustment” is a warning sign.

The forecast should finish with decisions and triggers

A useful forecast makes clear what management can still influence. It identifies the assumptions that need protection, the commercial decisions that need resolution, the actions that could improve the outcome and the triggers that would move the EAC. The goal is not to predict the future perfectly; it is to create the best available forward view soon enough to change it.

3. Step-by-step method — how to build and control the cost forecast

1. Confirm the forecast purpose, cut-off and basis. Define the reporting date, scope boundary, WBS/CBS/control account, currency/price basis, cost-recognition rules and whether the output is a working deterministic forecast, risk-adjusted forecast or another governed view.

2. Preserve the previous forecast and its assumptions. Retain prior ETC/EAC, time phasing, key commercial exposures, risks/opportunities and management actions so the current movement can be explained rather than overwritten.

3. Establish the reliable incurred-cost position. Use the M3.3 reconciled actuals and accruals at the same cut-off. Resolve material missing, duplicated or miscoded cost before adding remaining-work estimates.

4. Confirm the current authorised baseline and approved changes. Identify the base control budget, current authorised total, approved change, contingency/reserve and funding position. Keep these control values separate from the forecast itself.

5. Define the remaining authorised scope. Reconcile the latest WBS, quantities, deliverables, schedule and completion criteria. Identify scope that is complete, remaining, deleted, transferred or still awaiting formal change decision.

6. Reconcile all material commitments. For each purchase order or contract, identify value incurred to date, valid remaining commitment, cancelled/optional amounts, approved change and the scope still expected to be delivered.

7. Identify the commercial model that drives each remaining cost. Determine whether the work is fixed-price, remeasurable, reimbursable, target-cost, framework/call-off or uncommitted, and apply the forecast logic appropriate to that form.

8. Forecast the remaining committed scope. Estimate what the already-contracted work will finally cost using realistic remaining quantities, milestones, rates, productivity, price-adjustment rules, schedule and known change — not merely the open purchase-order balance.

9. Forecast uncommitted remaining scope. Use quotations, estimate build-ups, current market information, resource plans or other proportionate methods to estimate work that is authorised but not yet placed commercially.

10. Reassess productivity, resource mix and schedule-dependent cost. Use current demonstrated performance and the latest credible schedule. Include or remove overtime, premium resources, extended supervision, hire, logistics and indirect costs when the delivery strategy changes.

11. Apply escalation, indexation and currency assumptions consistently. Time-phase exposed future cost, document rate/index sources and effective dates, and distinguish hedged/fixed exposure from variable exposure.

12. Assess pending change, claims and commercial exposure. Review instructed but unapproved work, supplier submissions, disputed entitlement, remeasurement, provisional sums, incentive mechanisms and final-account items. Forecast a defensible exposure under governance without implying contractual acceptance.

13. Incorporate risks and opportunities without double counting. Identify which future uncertainties are already embedded in quantities, rates, productivity or commercial allowances; add only the governed residual exposure and show material opportunities separately until sufficiently credible.

14. Build the bottom-up ETC. Assemble remaining committed cost, uncommitted scope, commercial exposure, schedule/productivity effects, risk/opportunity treatment and close-out/final-account allowances. Reconcile every material component to an owner and evidence source.

15. Calculate EAC and time-phase the remaining forecast. Add incurred cost to ETC, then phase the remaining cost using the current schedule and commercial/payment logic. Maintain a separate cash view where payment timing differs from cost recognition.

16. Test scenarios, sensitivities and forecast confidence. Identify the assumptions most capable of moving the EAC and construct consistent alternatives — for example working, improvement and downside cases — without changing unrelated assumptions between scenarios.

17. Reconcile forecast movement and define management response. Bridge prior EAC to current EAC, distinguish approved change from performance/commercial movement, identify decisions and actions, and set triggers that will cause the forecast to be reassessed.

18. Review, challenge, approve and preserve the forecast. Perform independent checks, reconcile to cost/commercial/schedule/risk sources, record judgement, obtain required approval, issue concise management commentary and retain the period snapshot for future trend and assurance.

4. Worked Reference Project example — Community & Learning Centre

Continue the M3.4 Month-12 variance scenario for WBS 1.4. The 3.711m CU base control budget plus 0.089m CU package contingency gives 3.800m CU authorisation. Applying the M3.3 reconciliation method to that scenario produces 1.790m CU incurred cost; it does not carry forward the separate 1.834m CU dataset used in the M3.3 worked case. M3.4 shows adverse cost of accomplished scope and an EAC of 3.920m CU.

M3.5 now asks whether 3.920m CU is a credible forward forecast, what assumptions create the 2.130m CU ETC, what commercial exposure sits behind it, and what could move the final outcome.

Step A — start from a clean forecast equation

The team does not start by subtracting actual cost from the 3.800m CU authorised total and calling the remainder the ETC. That would force the forecast back to budget. Instead it begins with the reliable incurred cost of 1.790m CU and independently estimates what the remaining work is now expected to cost.

Current incurred cost = 1.790m CU. Bottom-up ETC = 2.130m CU. Working EAC = 1.790 + 2.130 = 3.920m CU. The forecast is therefore 0.209m CU above the 3.711m CU base control budget and 0.120m CU above the 3.800m CU authorised package total. Those comparisons remain visible; the forecast is not reduced simply because package contingency exists.

Step B — rebuild the ETC from the remaining work

The team decomposes the 2.130m CU ETC into the remaining physical and commercial work rather than relying on a single top-down adjustment. The control-account forecast is:

The table is not enough on its own. Each ETC value is supported by quantity, rate, productivity, contract and schedule assumptions held in the forecast working papers. If an assumption changes, the team can identify which part of ETC should move rather than applying a generic management adjustment.

Step C — reconcile commitments without treating them as the answer

Across the package, 1.355m CU of the 2.130m CU ETC relates to valid remaining committed scope. This amount is not copied blindly from open purchase-order balances. The commercial team has removed cancelled options, checked which milestones have already been accrued, updated measured quantities and allowed for the expected final value of remaining contracted work.

A specialist supplier has also submitted a 0.180m CU disruption/acceleration claim. The project has not accepted the claim. Based on current records, entitlement analysis and negotiation position, the commercial manager assesses 0.075m CU as the present forecast exposure. A further 0.040m CU is expected from remeasurement of authorised quantities. The forecast therefore includes 0.115m CU of pending commercial exposure while the commercial register continues to show the supplier submission, project assessment and approved amount separately.

This treatment avoids two poor extremes: assuming the claim is zero until settlement, or forecasting the full 0.180m CU as if submission equals entitlement. It also avoids contaminating the baseline; the 0.115m CU is a forecast judgement, not an automatic authorised budget change.

Step D — forecast uncommitted scope, uncertainty and opportunity explicitly

The package still has 0.415m CU of authorised but uncommitted remaining scope, principally late testing support, training, minor equipment and close-out services. Current quotations and resource build-ups support this forecast. In addition, the team carries 0.155m CU of identified remaining uncertainty within the working ETC under the organisation’s forecast convention: 0.070m CU for possible fire-interface acceleration/support, 0.055m CU for residual productivity exposure and 0.030m CU for price/currency movement on unplaced specialist items.

Two evidenced opportunities are also being pursued: removal of premium logistics and a lower-cost trained resource mix. Only 0.050m CU of opportunity is credited because that amount is supported by specific actions and current supplier/resource evidence; more ambitious savings remain management targets rather than forecast reductions. A separate 0.140m CU allowance covers defects, commissioning support, documentation and final-account close-out not fully represented in the open commitment balances.

The ETC can therefore be reconciled conceptually as: 1.355m CU remaining committed scope + 0.415m CU uncommitted authorised scope + 0.115m CU pending commercial exposure + 0.155m CU remaining uncertainty - 0.050m CU evidenced opportunities + 0.140m CU close-out/final-account allowance = 2.130m CU.

Step E — test schedule and productivity assumptions

The installation forecast no longer assumes the original 20 technology points per crew-day simply because that rate was used in the estimate. Recent stable production after the rework controls is 18 points per crew-day, with evidence that 19 may be achievable once room-readiness improves. The working ETC uses the demonstrated/reasonably achievable profile rather than the recovery target. If two consecutive reporting periods demonstrate the higher sustainable rate, the ETC can then be reduced with evidence.

The current schedule also shows that fire-system interface slippage could require specialist technology support to remain mobilised longer and could trigger premium working to protect integrated testing. Those costs are reflected in the 0.070m CU interface allowance rather than being ignored because the technology team itself is not causing the interface delay.

Step F — distinguish cost timing from cash timing

The 2.130m CU ETC is time-phased against the latest installation, configuration, testing and handover schedule. However, supplier milestone terms, 30-day payment terms and retention mean the cash profile is later than part of the cost-incurrence profile. The project therefore maintains a cost forecast for performance and an aligned but separate cash forecast for treasury/funding decisions. Moving an invoice into Month 16 does not move the underlying cost if the work is incurred in Month 15.

Step G — test scenarios without replacing the working forecast

Management wants to know whether the 3.920m CU outcome can improve and what downside remains. The team constructs three internally consistent scenarios. These are decision aids, not three different baselines.

The range between 3.820m and 4.080m CU is not presented as a probabilistic confidence interval. It is a scenario range that makes the principal assumptions visible. Quantitative risk analysis, if required, is handled through M4.3 using a controlled probabilistic method.

Step H — explain the movement from the prior forecast

The Month-11 EAC was 3.760m CU. The Month-12 working EAC is 3.920m CU, a 0.160m CU adverse forecast movement. Consistent with the M3.4 root-cause analysis, the bridge is explained by 0.065m CU of newly recognised rework, 0.045m CU of premium logistics and 0.050m CU from revised productivity/resource assumptions. The team does not bury this movement inside a new ETC total; it shows management exactly what changed in the evidence.

The pending commercial exposure and other remaining-work assumptions were already substantially reflected in the prior forecast, so they do not appear as new Month-12 movement merely because M3.5 analyses them in more detail. This distinction prevents double counting the explanation of forecast movement.

Step I — define decisions, actions and triggers

The team retains 3.920m CU as the working EAC and 3.820m CU as an improvement case. It agrees explicit triggers: sustained installation productivity at or above 19 points per crew-day; settlement of the specialist claim at or below the current 0.075m CU assessment; confirmation of the fire-interface date; elimination of premium freight for the next two lots; and award of remaining testing/training scope within the 0.415m CU allowance.

If the triggers are achieved, the next forecast can reduce using evidence. If productivity stays at 18 or below, the fire interface moves again, or commercial exposure increases, the downside case becomes more relevant and management may need to approve additional contingency/funding, change the delivery strategy or accept a higher final cost. The forecast therefore becomes a live decision model rather than a monthly number.

Step J — produce a decision-useful forecast statement

“At Month 12, WBS 1.4 has incurred 1.790m CU and has a bottom-up ETC of 2.130m CU, giving a working EAC of 3.920m CU. This is 0.120m CU above the 3.800m authorised package total and 0.160m CU worse than the Month-11 forecast. The ETC is based on 1.355m CU remaining committed scope, 0.415m CU uncommitted authorised scope, 0.115m CU current commercial exposure, 0.155m CU remaining uncertainty, 0.050m CU evidenced opportunities and 0.140m CU close-out/final-account allowance. The principal Month-12 forecast deterioration is rework, premium logistics and revised productivity/resource assumptions. A 3.820m CU improvement case remains achievable if productivity reaches a sustained 19 points per crew-day, premium logistics is removed and current commercial assumptions hold. A 4.080m CU downside case is retained for further interface delay and commercial/productivity deterioration. The 0.089m package contingency has not been netted automatically against EAC; any drawdown remains subject to the approved governance rules.”

This statement tells management the forecast, the build-up, the movement, the commercial basis, the opportunity, the downside and the governance boundary. “Forecast remains under review; team targeting budget” would not provide enough information to control the outcome.

5. Interpretation and professional judgement

Forecast what you believe, then manage toward what you want

The working forecast should represent the most credible current outcome. Recovery targets and management challenges are valuable, but they should sit alongside the forecast until the actions supporting them become credible. This protects trust in management information and makes the recovery gap visible.

Ask what must be true for the forecast to hold

Every material ETC has assumptions. For a supplier package they may include final quantity, delivery dates, claim settlement and indexation. For labour they may include remaining hours, productivity, crew mix and overtime. A strong forecast review asks which assumptions are evidence, which are judgement and which are management ambition — and what trigger would make each assumption change.

Do not mistake contractual position for economic expectation

Commercial teams may correctly maintain a robust contractual position while the project forecast recognises a non-zero exposure. Forecasting an expected settlement is not the same as conceding entitlement. Equally, recording zero merely because a claim is disputed can create a known understatement. The two disciplines should share evidence while preserving their different purposes.

Fixed price is not the same as fixed project cost

A lump-sum contract transfers some price/productivity risk, but the project can still face cost through scope change, relief/compensation events, indexation, delay, client risk, provisional items, insolvency/reprocurement or interface failure. The forecast should reflect the actual risk allocation and current facts rather than the contract label.

Uncommitted scope must not disappear from the forecast

Projects sometimes report attractive forecasts because major future packages have not yet been ordered. If the scope remains authorised and necessary, it needs an ETC even before procurement. Current market evidence or a proportionate estimate is better than zero.

Do not double count commitment, accrual and ETC

A common forecasting error is to add total commitments to actuals when part of those commitments has already been accrued or invoiced. Another is to include a supplier claim in both the commercial-exposure allowance and a generic risk allowance. Reconciliation should show where every material amount sits once — incurred, remaining commitment, uncommitted ETC, commercial exposure, risk/opportunity or governed reserve.

A favourable opportunity should earn its way into the forecast

Management ideas such as “negotiate 10% off”, “improve productivity” or “remove overtime” are not forecast savings until the delivery/commercial evidence makes them credible. The project may track them in an opportunity or recovery register and reduce ETC progressively as actions are agreed, implemented and demonstrated.

Avoid mechanical burn-rate extrapolation

Historical burn can be a useful challenge, especially for indirects or repetitive work, but it is not a substitute for understanding remaining scope. The final stages of a project often contain testing, defects, documentation, demobilisation and settlement costs that behave differently from earlier delivery. Conversely, mobilisation or early learning effects may not continue.

Forecast uncertainty should shrink as evidence improves — but not always monotonically

As scope is completed and commercial positions settle, forecast confidence should normally improve. However, new defects, interface delays, claims or market events can legitimately widen uncertainty late in a project. A widening range is not necessarily poor forecasting; hiding the new uncertainty is.

Schedule recovery may increase cost while improving project value

An acceleration option can increase package EAC yet protect the fixed public opening date and avoid larger project-wide consequences. The cost engineer should show the incremental cost and expected benefit rather than treating any increase in forecast as automatically undesirable. The decision belongs to integrated project management, informed by cost, schedule, risk and commercial evidence.

Separate cost forecast from funding sufficiency

A project can have a credible EAC but insufficient authorised funding, or enough funding but a forecast under the baseline. The forecast should not be altered to match available funding. Instead, the gap should trigger the appropriate governance decision: recovery, scope decision, contingency/reserve use, additional authority or another approved response.

Commercial settlement strategy can affect forecast timing and confidence

An unresolved final account may not change expected cost every month, but it can reduce confidence and consume management attention. The project should distinguish forecast value from settlement status and define when commercial uncertainty needs senior intervention. A long-running disputed item should not disappear merely because its forecast value has remained unchanged.

Use scenario analysis to expose assumptions, not to shop for a preferred answer

Scenarios are useful when they change a small number of defined drivers and show the resulting outcome. They become misleading when the “good case” assumes every favourable event simultaneously while the “bad case” assumes every adverse event without regard to correlation or plausibility. Scenario assumptions should be internally consistent and decision-relevant.

Forecast commentary should explain the forward story

Good commentary answers: what is the current EAC; what changed since last period; what remains to be spent; which commercial or delivery assumptions matter most; what uncertainty remains; what actions could improve the outcome; and what decision is required. It should not simply repeat the cost-to-date variance already explained in M3.4.

6. Practice diagnostic

Use this table to challenge the quality of the approach or deliverable. The rows consolidate the most important recurring red flags and checks; they are prompts for professional judgement rather than a substitute for the method above.

Evidence to retain

·       current and prior approved cost baselines and change history;

·       current and prior period ETC/EAC snapshots and movement bridges;

·       reconciled incurred cost, accrual and commitment extracts;

·       remaining-scope/quantity records and WBS/control-account mapping;

·       productivity, resource and schedule assumptions used in ETC;

·       purchase orders, contracts, amendments, rate schedules and relevant commercial terms;

·       commercial register showing supplier submissions, project assessments, approved values and forecast exposure;

·       quotation/market evidence for uncommitted work;

·       escalation, index and currency assumptions with source/effective date;

·       risk/opportunity assumptions and evidence of double-counting checks;

·       scenario/sensitivity assumptions and outputs;

·       forecast approvals, management actions, triggers and decision records.

7. Try-it-yourself practical exercise

Using the Community & Learning Centre Reference Project, develop a complete Month-12 cost forecast for WBS 1.4 Digital & Technology Systems. The exercise should demonstrate that you can move from reliable current cost to a transparent ETC/EAC, integrate commercial evidence and explain uncertainty without forcing the answer to the authorised budget.

1. Start with a 3.711m CU base control budget, 0.089m CU separately governed package contingency and 3.800m CU authorised total. State why these values are not automatically the forecast.

2. Use 1.790m CU as reliable incurred cost at Month 12. Explain why open commitments cannot simply be added to this amount.

3. Build ETC by cost element using the five worked-example categories: hardware/equipment, cabling/installation, configuration/integration, testing/training/handover, and package indirects/logistics. Make the total ETC equal 2.130m CU and document the basis of each element.

4. Reconcile 1.355m CU of remaining committed scope. Identify which amounts are fixed, remeasurable, subject to indexation or otherwise capable of changing before final account.

5. Include 0.415m CU of authorised but uncommitted scope and identify what procurement/market evidence would support the value.

6. Assess a supplier claim submitted at 0.180m CU. Create an evidence-based project forecast assessment and explain why forecast recognition does not equal contractual acceptance.

7. Include a further remeasurement or pending commercial item so total current commercial exposure is 0.115m CU. Show the supplier position, project assessment, approved amount and forecast exposure separately.

8. Create 0.155m CU of remaining uncertainty and 0.050m CU of evidenced opportunities. Demonstrate that none is double counted inside quantities, rates, commitments or contingency.

9. Include a 0.140m CU close-out/final-account allowance and explain which late-project costs it covers.

10. Calculate EAC and compare it with both the 3.711m CU base budget and 3.800m CU authorised total. Explain why both comparisons matter.

11. Use the current schedule to identify at least two ways that a delay or acceleration decision could change ETC, including one time-dependent indirect cost.

12. Produce separate cost and cash phasing for one supplier item with milestone payment terms or retention and explain the difference.

13. Create three scenarios: an improvement case around 3.820m CU, the 3.920m CU working forecast and a downside case around 4.080m CU. Change only explicit assumptions and explain the triggers between cases.

14. Bridge the Month-11 EAC of 3.760m CU to the Month-12 EAC of 3.920m CU using rework, premium logistics and revised productivity/resource assumptions. Ensure the bridge reconciles exactly.

15. Write a one-page management forecast narrative that states the EAC, forecast movement, ETC basis, material commercial exposures, key assumptions, uncertainty, actions, triggers and any governance decision required.

What good performance looks like

The exercise is successful when the learner can demonstrate that ETC is built from the remaining work rather than the remaining budget; commitments are reconciled without double counting; contract form changes forecast logic appropriately; pending commercial exposure is assessed objectively; risk, opportunity and contingency boundaries remain clear; cost and cash timing are distinguished; forecast movement is explained; scenarios expose assumptions rather than manipulate the answer; and the working EAC remains an evidence-based prediction even when management is pursuing a lower target.

8. Bridge to capability

The How-to teaches how remaining scope and delivery evidence become a cost forecast. At APPLIED and above, capability assessment should test whether the practitioner can build and defend a realistic ETC and EAC despite incomplete information, commercial exposure and optimistic targets. A reconciled forecast bridge, stated assumptions and scenario evidence should support the advice. Supporting work products are illustrative and should be assessed with the practitioner’s reasoning. Sample learning questions illustrate the judgement at each recognition level; they are discussion prompts rather than validated assessment items.

Learning question: Do you understand how remaining work and commercial evidence support a cost forecast?

Capability question for APPLIED and above: Can you demonstrate a credible EAC, defend its assumptions and advise honestly when expected cost differs from the target or authority?