# Engineering Change Impact on Open Orders

> Source: https://netray.co/erp-help/eng-engineering-change-impact-open-orders
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: ERP Help

## Short answer

Before releasing an engineering change, run a where-used on each changed part, then list open work orders, purchase orders, stock, WIP and customer orders that reference it, and set a disposition (use up, rework, scrap, return, or cut over). Record the decision per quantity so planners act on it instead of guessing.

## Kind

how-to

## System

it-leadership

## Erp

ERP (open orders and engineering change)

## Module

Engineering change impact analysis

## Query

engineering change impact on open work orders and purchase orders

## Alternate Queries

- what happens to open work orders when BOM changes
- ECO impact analysis open POs inventory
- where used before engineering change
- how to handle WIP when engineering change released

## Applies To

Discrete manufacturing ERPs with BOM, work order and purchasing modules; the exact screens and tables differ by product

## Steps

### How to assess the impact of an engineering change

**Items:**

- List the changed items at the new revision and run a multi-level where-used to find every parent assembly and finished good affected.
- Pull open manufacturing work orders for those parents, with their status, released quantity, completed quantity and the BOM revision they were released with.
- Pull open purchase orders and scheduled receipts for changed components, with supplier, quantity, due date and cancellation terms.
- Pull stock on hand by location and status (available, quarantine, in inspection) and any WIP that already consumed the old part.
- List customer orders and forecast demand for the affected finished goods, with promise dates inside the transition window.
- Choose an effectivity: a date, a work order number, a serial or lot break, or a quantity cutover, depending on the stock position.
- Assign a disposition per item and quantity and record cost impact: scrap value, rework labor, supplier cancellation charges.
- Hand the plan to planners and buyers as part of the ECN, and verify in MRP that the right actions appear after release.

## Sections

### Why a where-used is not enough

**Body:**

A where-used tells you which assemblies contain a part. It does not tell you whether any of them are actually being built, bought or sold in the next ninety days. Impact analysis connects structure to live demand and supply, and that is where the money is.

A multi-level where-used matters because a change to a sub-component can touch dozens of finished goods through phantom and intermediate levels. Single-level where-used reports miss these. Use the ERP's indented where-used or run a recursive query on the BOM table.

Pay attention to alternates and substitutes. A part used as a substitute in another BOM is invisible in a primary where-used and can surprise you in production when the old part has been scrapped.

**Code:**

-- Generic recursive where-used (adapt table and column names to your ERP)
WITH wu AS (
  SELECT parent_item, component_item, 1 AS lvl
  FROM bom_line
  WHERE component_item = 'CHANGED-PART'
  UNION ALL
  SELECT b.parent_item, b.component_item, wu.lvl + 1
  FROM bom_line b
  JOIN wu ON b.component_item = wu.parent_item
)
SELECT DISTINCT parent_item, lvl FROM wu ORDER BY lvl;

### Work orders: what usually happens to the BOM snapshot

**Body:**

Most ERPs copy the BOM into the work order at release, so a later BOM change does not alter an order that is already released. This protects the floor from sudden changes but means old revisions keep being built unless someone intervenes. Some systems let you refresh the work order BOM, with warnings about material already issued.

Decide per order. For a work order not yet started, cancel and reissue with the new BOM. For one in progress with partial issues, finish at the old revision if the change is not safety critical, or rework. For a safety or compliance change, stop, quarantine and rework regardless of cost, and record the reason.

Check the product record after a mixed build. If some units shipped on revision A and others on B, the as-built record should reflect which units used which revision. That matters for serialized products and for recalls.

### Purchasing and stock

**Body:**

Open purchase orders for the old part are a common source of cost. Check cancellation windows and supplier minimums early, because a supplier will often accept a change on an unshipped order but charge for finished goods. Buyers should be in the ECO review for this reason.

Stock disposition is the central decision. If the new revision is form, fit and function compatible, the old part can often be used up and the change made effective when stock runs out. If it is not interchangeable, you scrap, rework, return to vendor or sell. Record the book value at risk so finance sees the cost.

Be careful with quarantine and inspection stock. It is counted in on-hand totals but is not available, and it is easy to forget in a cutover plan.

### Customer orders and promise dates

**Body:**

A change that delays a build also delays shipment. Check customer orders and contract commitments for the affected finished goods, especially in the transition window. For defense and aerospace contracts, a change may also require customer notification or approval before it takes effect.

Communicate through the ECN to sales and customer service with the effective date and any expected delay, so they hear it from engineering rather than from a customer asking where an order is.

## Pitfalls

- Running a single-level where-used and missing assemblies that use the part through sub-assemblies or as a substitute.
- Assuming a BOM change updates open work orders, when most ERPs keep the released snapshot.
- Forgetting stock in quarantine, inspection or consigned locations when planning the cutover.
- Leaving buyers out of the ECO review, then discovering supplier cancellation charges after release.
- Releasing without a recorded disposition, so planners each interpret the change differently.
- Not recording which serials or lots were built to which revision on a mixed-revision build.

## Ai Angle

This is where a grounded assistant (ERPray, or SyteRay on SyteLine) saves the most manual effort. Asked about a part number, it can assemble the multi-level where-used, open work orders, open purchase orders, stock by location and affected customer orders in one answer, and show the queries behind it. It reads under the user's ERP permissions and does not change orders; releasing, cancelling or reissuing remains an approved action by a person.

## Faq

### Does changing a BOM change open work orders?

**Answer:** Usually not. Most ERPs snapshot the BOM into the work order when it is released, so existing orders keep the old structure. You must decide whether to finish, rework, or cancel and reissue them. Check your ERP's documentation, since some products offer a refresh option.

### What does use-up effectivity mean?

**Answer:** It means the old revision stays in use until existing stock is consumed, and the new revision takes over when that stock is gone. It suits interchangeable changes with low risk. It needs a stock check, a trigger that cuts over, and clear communication so the floor does not mix revisions.

### Who pays for scrap caused by an engineering change?

**Answer:** That depends on the cause and your contracts. Internal design changes usually fall on the company. Changes requested by a customer may be recoverable under the contract. Record the cost on the ECO at the time of decision so the impact is visible and can be claimed if it applies.

### How early should impact analysis be done?

**Answer:** Before the ECO is approved, as part of the review, not after release. Approvers can only weigh a change fairly when they see the cost of open orders, stock and delays. Doing it after release turns it into cleanup rather than a decision.

## Search terms

engineering change impact analysis, ECO impact open work orders, where used analysis BOM, engineering change WIP disposition, change effectivity use up stock, open purchase orders engineering change, BOM change open work orders, ECO cost of change, multi-level where used, engineering change supply chain impact

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