How to price engineering change orders

The customer changes a motor, material, control philosophy or delivery date after engineering and supply have started. The obvious cost sits in the revised parts list. The expensive part often sits elsewhere: drawings that must change twice, a supplier order that cannot be cancelled, completed fabrication that needs rework, another factory test, overtime to recover the date and project time spent controlling the change.

Many OEMs find those costs after the customer has accepted the change price. The estimator priced the final design as if the company had known it on day one. That answers the wrong question. The price must cover the difference between finishing the current order and finishing the revised one from its present state.

This guide builds that difference in a form engineering, operations, finance and the customer can audit. It also separates three numbers that teams often mix together: incremental cost, selling price and the amount the contract lets the OEM recover.

Freeze the estimate at one point in time

Set a cutoff date before the team calculates anything. Record the current design revision, supplier commitments, production status, actual cost, open purchase orders, remaining estimate and schedule. The same request can cost $40,000 before release and $240,000 after material arrives. A price without an execution-state date will become false while people review it.

Link the estimate to the exact customer request and order baseline. State what the customer wants, which accepted requirement changes and which units or serial numbers it affects. If the request remains unclear, price the defined interpretation and list the unanswered points as exclusions or risk items.

Use a before-and-after cost bridge

Calculate the remaining cost of the current order from the cutoff, then calculate the remaining cost of the revised order from the same cutoff. The difference captures future work. Add sunk cost that the change makes useless, cancellation charges, rework and change-specific execution costs. Subtract salvage, supplier refunds and work the OEM no longer needs to perform.

This bridge prevents two common errors. First, it does not charge the customer again for unchanged work already sold. Second, it does not pretend that the company can erase completed work simply because the revised product no longer needs it.

Official change-accounting guidance follows the same logic. FAR 43.203 separates nonrecurring engineering and obsolete or reperformed work, distinct new work, and recurring labor and material. The clause applies to specific government contracts, but its cost categories form a useful check for any complex OEM change.

Create a separate cost object for the change

Give the change its own project task, job, work breakdown element or cost code as soon as analysis starts. Charge engineering review, supplier cancellation, rework, extra material, retest and project hours to it. Unchanged work stays on the original order code.

Without a separate object, actual cost disappears into the base job. The estimator cannot compare the estimate with the outcome, finance cannot support the customer price and the next change uses another guess. Time booked before customer approval still belongs in the record, even if the company later chooses not to recover it.

FAR 52.243-6 requires separate accounts for direct costs of certain changed work, less applicable credits. The practical lesson is simple: estimate and collect the change through the same cost structure. A polished proposal has little value if the accounting system cannot show what the change consumed.

Price engineering by deliverable and iteration

Ask each discipline which released and in-progress objects must change. Count calculations, requirements, models, drawings, BOMs, software modules, interface documents, test procedures, manuals and customer submittals. Estimate review and release effort alongside authoring.

Do not price only the final edit. Engineers must inspect the current state, find dependencies, decide what remains valid, update the object, review it and answer downstream questions. A change received during customer drawing approval may also create another customer review cycle.

Use current labor rates and real capacity

Apply the rate that matches the cost method and period of performance. Separate direct pay, labor burden, engineering overhead and selling or general expense according to the company’s normal accounting policy. Do not add the same overhead once in the labor rate and again as a percentage of total cost.

Capacity changes the execution plan. Forty engineering hours during a slack month may use normal time. The same work during a release peak may delay another package or require contract labor. Price the action the team will actually take. If management chooses to absorb an opportunity cost, show it as a commercial decision instead of burying it in a padded hourly rate.

The FAR cost principles draw a firm line between direct and indirect treatment: a company should apply the same treatment to like costs in like circumstances. Private contracts may use different rules, but consistent treatment prevents double counting and makes the estimate easier to defend.

Build the material delta from disposition

For each changed item, record original quantity and cost, revised quantity and cost, current commitment, work completed and final disposition. The disposition matters as much as the price difference. An old component may return to stock, move to another project, incur a restocking fee or become scrap.

Use supplier confirmation for custom and long-lead items. A purchase-order value does not reveal cancellation exposure. Ask what material the supplier bought, which operations it completed, what it can reuse and when the revised part can arrive. Attach the answer to the estimate.

Apply credits explicitly. The current FAR Part 31 deviation guide tells contractors to reduce material cost by discounts, refunds, rebates, scrap, salvage and returned-material credits. Any fair internal method should do the same. Pricing gross added cost while ignoring a real recovery weakens the proposal and distorts margin.

Include rework, scrap and lost learning

Rework includes touch labor, disassembly, movement, cleaning, inspection, new setup, tooling changes, repair material, supervision and repeat quality records. If the work interrupts a production sequence, include the documented loss of efficiency or repeat setup caused by that interruption.

Treat scrap at its net cost. Start with the cost already incurred, add disposal and handling, then subtract salvage or reusable material. Do not price a new replacement and the full original material twice when some value remains.

If the change breaks a planned production run, calculate the effect from the actual routing and state. A broad “10% disruption” line will invite a challenge. Show which crew stops, which operation repeats and which quantity loses the expected learning or batch efficiency.

Price supplier changes from written responses

Send every affected supplier the same defined change and cutoff. Ask for added price, credit for removed work, cancellation or amendment charge, tooling effect, new lead time, validity and assumptions. If the supplier cannot quote before the customer deadline, include a named allowance and risk range.

Separate the supplier’s cost from the OEM’s work. The buyer must issue and track the amendment. Engineering may need to review a new drawing. Quality may need another source inspection. Logistics may change. The supplier price covers none of that unless its quote says so.

Calculate test, certification and documentation again

A design change can invalidate calculations, qualification evidence, inspection results and certificates even when the physical edit looks small. Ask quality and compliance which evidence remains valid. Price new test plans, customer witness time, laboratory fees, certification-body review, sample destruction and updated data books.

Documentation changes can reach manuals, nameplates, spare-parts lists, software records, training and translations. Include the number of affected documents and their approval cycle. A revised operating voltage on the machine without the same revision in the manual creates a field problem the change price should prevent.

Model schedule cost from a recovery plan

A later delivery date can add project supervision, storage, financing, rented equipment, site remobilization and extended supplier support. An earlier date can add overtime, split shipments, premium freight, parallel work and expedited supplier charges. Price the dated plan, not a generic acceleration percentage.

Build at least two cases when the customer has a choice. One case shows the natural date at normal execution cost. Another shows the requested date and each recovery action. The price difference gives the customer a real schedule decision.

Separate disruption from the changed work

Changed work has a direct scope. Disruption is the effect on otherwise unchanged work: crews wait, sequences break, engineers switch context, a line stops or a test slot disappears. Estimate disruption only when the team can explain the cause, affected work, duration and calculation.

Use records available at the cutoff: schedule logic, time bookings, production transactions, hold notices, queue changes and resource plans. Compare the planned and revised method. If the company has no evidence, present the exposure as a risk range instead of a false exact amount.

Apply overhead once and consistently

Use the company’s normal costing structure. Direct engineering may carry engineering burden. Shop labor may carry factory overhead. Material may carry purchasing or handling burden. General and administrative expense may apply to an accepted base. Write the rate, base and period beside each calculation.

Check every rate for double counting. A fully burdened shop rate should not receive the same factory overhead again. A supplier quote may already include freight. An expedite fee may already include overtime. Reconcile the estimate from raw cost to total cost so finance can see every layer.

Do not remove overhead from deleted work while leaving the same fixed expense spread over less production without thought. Credits should follow the contract and pricing method, while internal margin analysis should show the real cost behavior. The customer price and the internal economic effect can differ.

Credit deleted work on the same logic

A deletion credit is not automatically the original selling price of the removed item. The OEM may have completed design, ordered material or incurred setup before deletion. Calculate which future costs the company truly avoids, which committed costs remain and which recoveries it receives. Then apply the agreed pricing rule.

Use the same structure for adds and deletes. If added subcontract work receives material handling, overhead and margin, decide how the contract treats those elements on deleted subcontract work. Inconsistent treatment creates a one-way price formula that customers will challenge.

A longstanding GAO review of credit change orders identified exactly this asymmetry: overhead and profit appeared on added work while deletions received no corresponding adjustment. The report concerned GSA construction contracts, but the warning applies to OEM pricing. Show additions and credits through one visible bridge.

Add contingency by named risk

List uncertain quantities, supplier responses, engineering hours, test outcomes and schedule assumptions. Give each risk a range and basis. Use expected value or another approved method. A flat contingency percentage hides which uncertainty the customer can remove with a quick decision.

Do not use contingency to cover missing scope the team could define. Ask the question, get the supplier quote or complete the impact review. Retain contingency for uncertainty that remains after reasonable analysis. State whether unused contingency stays in the fixed change price or reconciles later.

Set price from the revised commercial exposure

Once the team has incremental cost, set the selling price. Apply the margin target for the product, customer and risk. A change that consumes scarce engineering capacity, weakens performance confidence or creates a compressed date may deserve a higher return than the original order. A strategic concession should appear as a visible discount with named approval.

Check the contract before presenting the price. It may define labor rates, markups, notice periods, audit rights, fee limits or time-and-material treatment. Those terms govern the recoverable amount. The internal cost estimate still needs the full economic effect so management can see any gap it chooses or must absorb.

Reconcile the customer price to the estimate

The proposal total should reconcile to a controlled estimate version. Every line should have a basis: quantity, hours, rate, supplier response, routing, historical case or explicit allowance. Keep internal margin and sensitive supplier detail in the approval view while giving the customer enough structure to understand the price.

If negotiation changes the price, record the concession against the same estimate. Do not edit cost down to make the agreed margin look better. The final record should show target price, concession, agreed price and remaining exposure.

Worked example: change a conveyor drive after fabrication starts

An OEM has a $4.8 million order for a bulk-material conveyor system. The customer asks for regenerative drives and a higher hazardous-area classification after electrical drawings have been approved. Panel fabrication is 35% complete. The drive supplier has started the original units. The customer still wants the accepted shipment date.

The team sets Tuesday at 4 p.m. as the cutoff. It creates one change cost code and freezes the current configuration, WIP and commitments. Engineering identifies 312 hours across controls, electrical, mechanical interfaces, software, checking and manuals. At current rates and burdens, engineering adds $48,600.

The new drives cost $74,000 more. The supplier charges $21,500 for work already completed on the old units and credits $8,000 for reusable components. Panel rework adds $32,700. Repeat certification and FAT add $18,400. Project control, procurement and quality add $11,800. Premium freight, overtime and a second test shift add $39,000 to hold the date. The OEM removes $6,500 of unperformed original work.

Incremental cost equals $232,500. Three named risks add $17,500 of expected cost, bringing the priced cost to $250,000. At the approved margin, the target customer price is $322,600. Commercial management approves a $12,600 concession for the account, so the proposal is $310,000 with a seven-day validity and a customer decision deadline tied to the supplier slot.

The customer asks why the drive price delta is only $74,000 while the change costs $310,000. The proposal shows the answer without exposing internal margin: engineering release, supplier settlement, panel rework, certification, schedule recovery and changed documentation. The customer accepts the price. Actual cost closes at $244,800, 2.1% below the priced cost.

Review actual cost when the change closes

Compare estimated and actual hours, material, supplier charges, rework, schedule recovery and credits. Explain the variance by cause. Do not stop at total favorable or unfavorable cost. A favorable supplier outcome can hide an engineering overrun that will repeat on the next change.

Feed the result into standards and future bids. If panel rework repeatedly takes twice the estimate, update the routing or model. If customer decisions routinely expire supplier validity, shorten the proposal window or price the exposure. If many changes originate in unclear product options, repair configuration and proposal rules upstream.

SAP’s preliminary manufacturing order costing compares planned cost with later production variance and recalculates planned cost when an order changes, depending on setup. That same planned-versus-actual discipline should exist for each material engineering change.

How Bourne builds the change price

Bourne starts from the accepted order, current configuration and execution state. It collects engineering impact, supplier responses, purchase commitments, WIP, actual cost, remaining work, schedule options and contract rules. The result is one before-and-after price bridge with a source behind every material number.

The application can draft requests to suppliers and internal owners, assemble the change estimate, identify missing credits and flag rates or cost categories that appear twice. Estimators and commercial leaders approve the cost basis, risk, margin and customer presentation.

After agreement, Bourne writes the approved value and scope to CRM, ERP and project records, then tracks actual cost against the estimate. The next engineering change starts with measured rework, supplier and schedule history from comparable work.

Use a live change to test the method

Pick a current change with released engineering, at least one supplier commitment and a schedule question. Rebuild the estimate with the bridge in this guide. Require written dispositions for affected material and WIP. Ask every discipline to name its deliverables and hours. Build a normal-date and recovery-date option.

The test passes when the cost reconciles, deleted work receives a supportable credit, no overhead appears twice, each risk has a basis and the proposed price ties to the approved estimate. Continue charging actual work to the same cost object until closure.

Then compare the result with the company’s original shortcut. The difference is usually where margin has been leaking: stranded commitments, engineering iteration, repeat verification, schedule recovery and work performed before the customer signs.

Arda Bulut

Arda Bulut is the co-founder and CTO of Bourne and HockeyStack. He leads engineering at Bourne, building the platform people use to create AI products, agents and automations.