How ERPNext scrap management affects finished goods cost
A manufacturer's finished goods cost drifts when scrap is not recorded the same way on every production run. Scrap that is written off informally, left unposted, or booked against the wrong warehouse leaves the costing of finished goods unreliable, even when the bill of materials looks correct on paper. In ERPNext, the controls that matter sit in three places: scrap items defined on the BOM, the scrap warehouse that receives them, and the scrap quantities entered on the manufacture stock entry when a work order is completed. Together these decide how much of the raw material cost lands on good units and how much is written off as loss.
Teams usually need this setup once production runs regularly enough that yield varies between batches or shifts, or once finance needs finished goods valuation to match what the shop floor actually consumed. Process plants, cutting and forming operations, and any line where a known share of input never becomes a sellable unit are typical cases. The valuation question is simple to state and hard to answer by hand: when a unit is finished, which share of the input cost belongs to it, and which share belongs to material that was lost. Your team should confirm in its own ERPNext version how scrap items on a BOM are calculated and how the manufacture entry values them, using the ERPNext repository and its documentation as the starting point, and test the result with one representative item before rolling it out.
Which scrap approach fits your production
Discrete assembly plants build countable units from defined components, and scrap usually shows up as a predictable share of a few part numbers, such as cut-offs from a stamping step or rejected welds. In ERPNext, this is the case where scrap items can be modelled in the BOM so that expected scrap is planned, costed and visible at the time the work order is created. The scrap quantity is then recorded against the manufacture entry so that the actual loss is compared with the expectation.
- Scrap items in the BOM: Add the recurring scrap material to the BOM as a scrap item so planned scrap is shown in material requirements and costing.
- Scrap warehouse: Point scrap to a dedicated scrap warehouse so scrapped stock is kept apart from saleable finished goods.
- Scrap at manufacture: Record actual scrap quantities on each manufacture entry so variance against the BOM is visible per work order.
- Stable part numbers: The approach works best when scrap rates for each operation are reasonably steady across runs.
- Costing effect: Confirm how scrap cost flows into the finished goods valuation in your version, since it depends on your valuation method and BOM costing settings.
Before committing, check with your production engineers whether scrap for each part is stable enough to plan in the BOM, and confirm the exact scrap and valuation behaviour in your ERPNext version.
Process plants lose material through yield loss, evaporation, off-spec batches and by-products, so the amount lost often depends on batch conditions rather than a fixed component list. Modelling every loss as a BOM scrap line can become misleading, because the loss varies with batch size, grade and equipment state. Process operations usually need the actual quantities recorded per batch, with the finished output reflecting what was really produced, and the difference treated as process loss.
- Batch-level recording: Record actual input and output quantities per batch so loss reflects the real run rather than a standard percentage.
- Different finished grades: When QC finds a lower grade than planned, the output may need to be recorded differently from the original plan, which affects how loss is reported.
- Scrap kept out of the BOM: Keep variable losses out of the BOM when they depend on batch conditions, and record them at manufacture instead.
- By-products: Where a process yields secondary products, decide whether they are tracked as items or treated as loss, since this changes valuation.
- Quality gates: Link loss recording to inspection outcomes so that rejected output is accounted for consistently.
Ask your process engineers and quality team how loss is measured in practice, and confirm with the implementation team how batch, grade and by-product records should be set up in the version you run.
Many sites run both discrete lines and process steps, or assemble products that include a process-made sub-assembly. The common mistake is to apply one scrap method everywhere, either planning every loss in the BOM or recording everything ad hoc. A mixed site usually needs a rule for each product family, so that stable scrap is planned and variable loss is recorded at the point it occurs.
- Product family rules: Decide per product family whether scrap is a planned BOM line or a recorded variance.
- Sub-assemblies: Scrap from a process-made sub-assembly may need to be handled in that sub-assembly's manufacture, not in the parent BOM.
- Warehouse design: Use scrap warehouses consistently across lines so reports can compare losses between sites.
- Reporting consistency: Agree on the same definition of scrap and process loss across both kinds of production so costing and variance reports stay comparable.
- Multi-level BOMs: Plan scrap at each BOM level, since losses in one level affect the quantities required at every level above it.
Check with your planners and cost accountants which rule applies to each product family, and document it before the BOMs are built, so the setup is consistent from the start.
Scrap configuration options and when each fits
This table compares the four ways ERPNext records scrap in manufacturing, from planned scrap set on the BOM to manual entries for loss found outside a production run. Read each row for when the option fits, how it moves quantity and value between stock and the finished goods line, and what to check in the version you run. The main takeaway is that predictable scrap should be set up once in the BOM, while unplanned loss needs a documented entry and an account that keeps the cost visible.
| Option | When it fits | What it changes in stock and valuation | What to confirm in your ERPNext version |
|---|---|---|---|
| Scrap items on the BOM | Predictable scrap per unit produced, such as trim, offcuts or setup waste that recurs on every run | Generates scrap lines on the manufacture entry in proportion to output, so scrap leaves the consumed stock and its value shifts to scrap rather than the finished good | How the scrap quantity is calculated for a work order quantity, and how the scrap item's valuation rate is set |
| Scrap warehouse designation | Scrap must be held apart from saleable stock for counting, sale to a recycler or disposal | Directs scrap quantities into a dedicated warehouse so they stay out of available stock for sales and planning | Which document or setting carries the scrap warehouse, and whether reports and reorder logic exclude that warehouse |
| Scrap quantities entered on the manufacture entry | Loss varies by run and the operator knows the actual scrap after production | Adjusts the consumed and produced quantities on the entry, so the finished goods receipt reflects actual output | Whether scrap lines can be edited on the entry, and whether the change needs a reason, approval or a later correction entry |
| Manual stock entries for scrap | Scrap is found after inspection, sorting or stock counting, outside a normal production run | Issues the scrap out of stock through a stock entry, so its value leaves the stock line and is booked to the account you select | The entry type to use, the expense or adjustment account to post to, and whether your approval controls require sign-off |
Setting up scrap in ERPNext step by step
This sequence turns scrap from an informal write-off into a tracked, valued stock movement inside ERPNext. Each step builds on the one before, so the finished setup shows scrap quantities and cost in the stock ledger and in finished goods valuation.
Define scrap warehouses and item groups
Create one or more warehouses dedicated to scrap or rejected material, nested under your company's warehouse tree so they appear in stock reports as their own locations. Then create or confirm an item group for scrap and by-product items, so that scrap goods can be filtered and reported separately from saleable stock. Your controller or inventory lead should approve the warehouse names and account mapping before anything is posted. The step is done when the warehouses and item group are saved, each warehouse is linked to a company, and a test search by item group returns the expected items.
Create scrap items and set their valuation
Create a stock item for each type of scrap you recover, such as metal offcuts or reusable packaging, and set its stock UOM and valuation method in line with how your finance team values waste. Decide whether scrap has a recovery value and, if so, how that value is set, because this determines the cost left on finished goods. Confirm the expense or income account with your accountant before the first posting. The step is complete when each scrap item saves without errors and a sample valuation rate can be traced to a stated source.
Add scrap items to the BOM
Open the BOM for a test finished good, add the scrap item in the scrap items table with the expected scrap quantity per unit produced, and confirm the BOM is submitted and set as default for that item. Production planning and costing both read this table, so an incomplete entry affects later reports. Ask the production engineer to confirm the expected scrap rate for the test product. The check is that the BOM shows the scrap row and the BOM cost report reflects the scrap line without changing the main component quantities.
Run a test work order to completion
Create a work order from the test BOM for a small quantity, then issue materials to the work order through a material transfer for manufacture. Complete the production by creating a manufacture entry, entering the finished quantity and the actual scrap quantity recorded on the shop floor. Use a test company or a sandbox site where possible, because the entry posts stock and accounting. The step is done when the manufacture entry is submitted and the work order status updates to completed or the expected partial status.
Reconcile scrap against material consumed
Before accepting the manufacture entry, reconcile the quantities. Starting with raw materials consumed, subtract the finished goods produced and the scrap recorded in the scrap warehouse, then compare the remainder with the process loss your production team expects. Any gap points to a missing scrap line, a wrong unit of measure, or a sub-assembly that was not transferred. The check passes when the balance is zero or the difference is an explained loss that the production lead has signed off.
Verify the stock ledger and valuation impact
Open the stock ledger for the scrap item and the finished good, then confirm that scrap quantities arrive in the scrap warehouse and that raw material outflows match the work order. Check the stock balance report and the valuation of the finished good, making sure scrap cost is not spread onto saleable units in a way your policy does not allow. Ask your accountant to review the general ledger postings generated by the entry. The step is complete when the stock ledger, stock balance and general ledger entries match the reconciliation from the previous step.
Document the approved setup and test edge cases
Write down the warehouse names, item codes, BOM versions and posting rules that were confirmed, and record who approved each one. Repeat a short test with an edge case, such as a partial completion or a cancelled manufacture entry, to confirm that reversing it restores stock and valuation correctly. Keep the test evidence with the change record so that auditors and finance reviewers can trace how scrap is accounted for. The step is complete when the procedure is signed off and the edge case results are attached to the setup record.
Where scrap accounting goes wrong
Scrap errors rarely show up on the day they happen. They surface later as finished goods valued too high or too low, stock that does not reconcile, or quality reports that disagree with the books. The five risks below are where teams should look first when reviewing a scrap setup in ERPNext.
Scrap recorded inconsistently across shifts
When one shift posts scrap as a manufacture entry and another adjusts stock by hand, the same kind of loss ends up in different places. Scrap posted to the wrong work order or left unrecorded also skews yield and cost per unit. Check that every shift follows the same entry method, that scrap quantities are entered against the work order they came from, and that a supervisor reviews unusual totals before the period closes.
Scrap items missing from BOMs
If a BOM does not list the scrap items a process produces, the system has no expected scrap to compare against actual output. Planned material use and costing then understate what the process really consumes. Review each BOM against the process, confirm which scrap items and expected quantities belong in it, and confirm that the item master for each scrap item carries the right unit and valuation settings.
Scrap warehouses mixed with saleable stock
When scrap is received into the same warehouse as saleable finished goods, available stock counts include material that cannot be sold, and reorder and planning figures become unreliable. Keep a dedicated scrap warehouse in the warehouse tree, make sure sales and planning look only at saleable warehouses, and review periodically whether scrap has been moved out, sold or written off.
Valuation distortion in costing
Scrap that carries no value, or carries a value copied from the good product, shifts cost between finished goods and waste. Finished goods can look more or less expensive than they are, and margin reports follow the error. Decide with finance how each scrap item is valued, test a sample work order through to its valuation, and confirm that the valuation method for scrap matches the one your accounting policy describes.
Reconciling scrap with quality records
Quality inspections often record rejected units or grades that never reach the scrap entry in ERPNext, so the quality log and the stock ledger describe different losses. A regular reconciliation between rejected quantities in quality records and scrap quantities in stock entries exposes gaps early. Agree which system is the source for rejected quantities, and document how a difference is investigated and corrected.
Controlling who records and approves scrap
The control question is simple to state: who may record scrap against a production run, and who may change the scrap quantities built into a BOM. In most plants these should be different people. Shop floor operators or supervisors usually record what was lost during a work order or job card. Production planners or costing staff are the ones who should adjust the scrap percentage or scrap item on a BOM, because that change moves planned material cost for every future order that uses it. Decide this split before go-live, then map it to ERPNext roles and permissions. Confirm the exact role names, and which document types each role can create, submit and cancel, in the roles and permissions area of your own ERPNext version, since names and defaults can change between releases.
Permissions alone do not show who did what. Every submitted document in ERPNext carries version history and a timeline of changes, and the Activity log records logins and certain actions. Check whether your version and configuration capture the fields you need for review, such as the user who submitted a stock entry, the time of the change, and the previous BOM values. Test this in a staging site: submit a scrap entry as an operator, edit a BOM as a planner, then confirm that both actions and their before and after values are visible to an auditor who has read-only access. Also decide who may cancel a submitted entry, because a cancellation followed by a corrected entry is a common way to hide a loss.
Plan the approval step for changes that matter to the books. ERPNext supports approval workflows, but whether a scrap entry or BOM change needs a second person to approve before it affects stock valuation is a process decision you must design and configure yourself. Write down the thresholds that trigger review, such as any change to a scrap percentage on a high-value item, and the person who signs off. Then confirm with your auditors how they want this evidence retained. Ask your implementation partner to document the role matrix, the approval rules and the audit test steps together, so the control can be shown to an external reviewer as one design rather than as scattered settings.
Security and operational considerations
Scrap percentages and scrap warehouses sit inside BOMs and stock entries, so the controls on those documents decide whether scrap figures can be trusted. The cards below cover who can change them, how to protect data before bulk edits, and how scrap postings reach valuation and reports.
Restrict who edits BOMs
A BOM's scrap percentage and scrap items drive the material consumed and the cost of every work order that uses it. Limit BOM create and submit rights to a small group, and separate those rights from the people who post manufacture entries. Confirm in your own test site which DocTypes and fields the standard role permissions expose before you assign roles to production staff.
Control stock entry permissions
Manufacture and material transfer entries are where scrap quantities enter the ledger, and a wrong warehouse or quantity there changes finished goods valuation. Decide which roles can submit, amend or cancel stock entries, and who may write to scrap warehouses. Ask your implementer to demonstrate the cancellation and amendment path so reviewers can see how a posted scrap quantity is reversed.
Back up before bulk BOM updates
Updating BOMs in bulk can change scrap percentages across many products at once, and the change is hard to unwind by hand. Take a verified database backup and export the affected BOMs before the run, then compare costing before and after on a copy of the site. Confirm the restore procedure with your operations team, because a backup that has never been restored is not yet a recovery plan.
Change control for scrap percentages
A scrap percentage is an engineering assumption that feeds purchasing, costing and planning, so changes should follow a documented approval. Record who proposed the new percentage, the trial data behind it, and the effective date, and keep the previous BOM version for audit. Where the BOM is customized through scripts, confirm that server-side changes are tracked in version control and not made only in production.
Scrap data in reports
Scrap quantities recorded on manufacture entries flow into stock ledgers, valuation and the production variances that management reviews. Define which warehouse holds scrap, how scrap is valued, and which reports will show process loss by product and workstation. Ask the implementer to produce a sample variance report from test data so finance and operations agree on what each figure means before go-live.
Confirm scripts and custom logic
Custom scripts that calculate scrap or block postings add behavior that auditors and administrators must understand. From version 15, Server Scripts are disabled by default and must be enabled with the server_script_enabled setting, and public shared Frappe Cloud benches do not allow them. Confirm where scripts will run, who may author them, and how they are reviewed before they touch scrap calculations.
Scrap management questions buyers ask before hiring help
What drives the cost of setting up scrap management in ERPNext?
The main cost driver is how many items, BOMs, operations and warehouses carry scrap rules, because each one needs configuration, testing and sign-off. Cost is mostly consultant or engineer time, paid once for the setup and then as needed for changes. The number of sites or companies, whether scrap must post to the general ledger differently by plant, and whether any custom logic is required all add effort. Ask any partner for a quote that lists each BOM family, operation, warehouse and valuation rule in scope, and separates one-time build work from ongoing support.
How long does a scoped scrap management setup take?
Duration depends on scope, not on a fixed template. A single plant with a few BOMs and one scrap warehouse is a much smaller job than several plants with multi-level BOMs, operation-level scrap and custom reporting. Ask for a timeline in the written scope that names the phases: process review, configuration, test entries on sample work orders, valuation check against your accounting period, and user training. No duration is stated here because the supplied facts do not give one for this work.
What must our team provide before the work starts?
Your team needs to provide the material that defines how scrap is created and valued. That usually includes:
- Current BOMs with scrap percentages or scrap items, and which operations produce them
- Costing rules and the valuation method used for finished goods and scrap
- Warehouse structure, including where scrap is held and who approves its release
- Your accounting policy for scrap write-offs, gains and process loss
- Examples of recent work orders and stock entries so the setup can be tested against real behavior
Missing valuation policy is the most common reason setup stalls.
Can an internal ERP team set up scrap management alone?
Often yes, if the team already runs ERPNext manufacturing and has an accountant who can sign off valuation. The configuration itself is not unusually complex, but the accounting treatment of scrap and the effect on finished goods valuation need careful review, and mistakes appear only after period close. Internal teams usually struggle with testing across many BOMs and with keeping the process consistent across sites. A partner is most useful for an independent review of the design, for test scripts and for training. Confirm what your own team can cover before deciding.
What goes wrong most often with scrap in ERPNext?
The most common failures are scrap items missing from BOMs, scrap warehouses that are not linked to the right accounts, and scrap entered in manufacture entries without matching stock movements. These errors shift cost between scrap and finished goods, so the valuation looks correct until a reconciliation is run. Engineers should test a full cycle: create a work order, record consumption and scrap, complete production, then check the stock ledger and general ledger for the expected balances before go-live.
Do we need custom code to handle scrap properly?
Usually not. Standard BOM scrap settings, scrap warehouses and manufacture entries cover most plants. Custom logic becomes a question when you need scrap rules that depend on product grade, shift or customer, or reports that ERPNext does not produce out of the box. If custom scripts are needed, check your environment first: Server Scripts in Frappe version 15 and later are disabled by default and must be enabled with the server_script_enabled setting, and Frappe Cloud public shared benches do not allow them. Plan for that in the scope.
What does ongoing support for scrap management involve?
Ongoing work is mainly review after each change to BOMs, operations or warehouses, plus upgrades. ERPNext releases minor versions frequently, and each major version has a support end date, so the setup should be retested after upgrades. Support can be handled internally or through a retainer, which is recurring work agreed in writing. Ask what is covered for testing, regression checks and change requests, and how fast a change is handled, since response times should be confirmed in the contract, not assumed.
How DeployOpen scopes scrap work
DeployOpen starts scrap work with a written scope agreed before any configuration begins. The scope names the BOM structure that will carry scrap, the warehouses that will receive it, the manufacture cycles that will be run as test builds, and the validation evidence that will show the accounting behaves as intended. Because most engagements are fixed-scope, the deliverables and timeline are fixed in writing too, so the client knows what is included and what would be a change request. The first decisions to settle are which items are scrap and which are by-products, whether scrap sits as a scrap item on the BOM or is recorded at manufacture, and who in finance will sign off the valuation outcome.
The scope then defines the test manufacture cycles. DeployOpen plans a small number of work orders in a non-production copy of the site, covering a normal run, a run with scrap recorded in the manufacture entry, and a run where the finished quantity is short. For each cycle, the reader should expect a stock ledger and general ledger check showing where the scrap value went, whether the scrap warehouse balance moved as planned, and whether the finished goods valuation matches the costing the finance team agreed. Validation results are recorded as part of the deliverables. Confirm with DeployOpen which accounts, cost centers and warehouse permissions the test cycles need and who in your organization will review the results.
After delivery, ongoing support is optional and sold as a separate retainer. A retainer can cover changes to BOMs as products are revised, review of scrap entries after a process change, and help with period-end reconciliation between stock and accounts. It does not promise any particular scrap rate or cost outcome, since those depend on your process, your quality data and your operators. Ask for the scope document to list the handover items, the named contacts on each side, and the conditions under which a change would move to a new written scope.
How DeployOpen delivers ERPNext manufacturing work
DeployOpen plans, implements, customizes, documents and supports self-hosted open-source platforms inside your own infrastructure, including ERPNext. For scrap management, we start by agreeing in writing how scrap items, scrap warehouses and valuation rules will work with your BOMs and manufacture entries, then build and test that design before go-live.
How we scope
- Written scope lists which BOMs, scrap items and scrap warehouses are covered and who maintains them.
- We agree how scrap in manufacture entries will be recorded, approved and reviewed before any configuration starts.
- Engagements are fixed-scope, and ongoing support is available as a retainer once the scope is delivered.
How we build
- We configure scrap items in BOMs and test that expected scrap quantities post to the intended warehouse.
- We test finished goods valuation with scrap in sample work orders, including cases with partial completion and rework.
- Where your process needs custom fields or scripts, we build them without forking ERPNext and review them against your change process.
How we hand over
- You receive documentation of BOM scrap settings, warehouse structure, posting steps and valuation effects.
- We walk your production, stores and finance teams through month-end checks for scrap and process loss.
- Handover includes a record of configuration, test cases and open items, so your team can confirm each decision.
How we support
- Support covers ERPNext upgrades, patches and changes to BOMs or scrap rules as your products and processes change.
- Retainers can include periodic review of scrap postings and valuation reports with your finance and production leads.
- Before any version change, we review release notes and test scrap postings in a staging copy of your system.
