```json { "title": "Scrap and Yield Variance Tracking for Steel Re-Rolling Units in ERPNext", "url": "https://aavatto.com/blog/scrap-tracking-steel-manufacturing-software-erpnext/", "datePublished": "2026-10-21", "dateModified": "2026-10-21", "language": "en-US", "description": "How steel re-rolling units use ERPNext as scrap tracking steel manufacturing software to measure yield variance by heat, shift and loss type.", "author": "Aavatto", "publisher": "Aavatto - Frappe & ERPNext Experts | Custom Development, Implementation & Support" } ``` # Scrap and Yield Variance Tracking for Steel Re-Rolling Units in ERPNext If you run a re-rolling mill, you already know roughly how many tonnes of billets go into the furnace and how many tonnes of TMT bars, angles or channels come out. What most units can't answer is where the difference went, on which shift, from which heat, and how much of it could have been recovered. That's the job scrap tracking software has to do, and ERPNext can do it if it's set up around how a rolling mill actually loses material. What is scrap tracking steel manufacturing software? It's a system that records every input tonne and every output tonne in a steel unit, splits the gap into specific loss types (scale, end cuts, miss-rolls, rejects), values each one, and compares actual yield against a standard yield per product, heat and shift so variances are visible within days, not at month-end. ## Why yield variance hurts re-rolling units more than most Re-rolling runs on thin margins and a single dominant raw material. When input is billets or ingots and output is sold by weight, a small, persistent yield gap flows straight into cost per tonne. Unlike an assembly plant, you can't blame "a few defective units"; the loss is spread across the furnace, the stands and the cooling bed. The other problem is timing. Many units reconcile yield only when the monthly stock count exposes it. By then the shift, the roll set and the billet lot that caused the loss are hard to trace. Yield variance tracking only works if the numbers exist per heat or per production run, not per month. ## Where the tonnes go: loss types in a re-rolling mill Before configuring any software, agree internally on what counts as which kind of loss. Each type has a different cause, a different recovery value and a different owner. Loss typeWhere it happensRecoverable?Usually owned byBurning / scale lossReheating furnace, descalingPartly, sold as mill scale at low valueFurnace teamEnd cuts (crop ends)Shears at head and tail of barYes, sold or sent for re-meltingMill / shear operatorMiss-rolls and cobblesStands, when a bar jams or breaksYes, as heavy scrapMill team, roll shopShort lengthsCooling bed, cut-to-lengthOften sold as seconds at a discountFinishing / dispatchOff-size or rejected barsQuality checkSold as seconds or scrapQualityOverweight rollingWhole mill, if section weight runs above nominalNot recovered, given away in the saleMill team, sales The last row is the one generic scrap tools miss. If you invoice bars on theoretical weight but roll them heavier than nominal, no scrap is created at all, yet you are giving material away on every bundle. A proper steel re-rolling ERP setup should compare actual weighed output against theoretical weight so this shows up as a variance. ## What scrap tracking steel manufacturing software needs to capture Whatever system you use, it has to hold four things together for each production run: **Input weight** by billet lot or heat number, ideally from a weighbridge **Good output weight** by section and size, weighed, plus theoretical weight for comparison **Scrap and loss weight** split by the loss types above **A standard yield** for that product, so actual can be compared against expected If any one of these is missing, the variance you report is really just "unexplained difference", which is what most units already have. ## Setting up yield variance tracking in ERPNext ERPNext's manufacturing module already has the building blocks. The work is in configuring them to match the mill rather than using the defaults. Define scrap as real items Create separate stock items for each recoverable scrap type (end cuts, miss-roll scrap, mill scale, short-length seconds, off-size seconds), each in kg or MT. Give each a realistic valuation rate based on what you actually sell or re-melt it for. This matters because ERPNext deducts the value of scrap from the cost of the finished goods, so a wrong scrap rate quietly distorts your cost per tonne. Build BOMs that carry standard yield For each finished section, create a BOM with the billet as the raw material, the expected scrap items in the BOM's scrap table, and the expected unrecoverable loss (mainly scale) as a process loss percentage. Together these define your standard yield for that product. If different mills or sizes behave differently, use separate BOMs rather than one averaged figure. Run production through Work Orders tied to heats Raise a Work Order per production run and use batches to link input billets to their heat number. When the run closes, the Manufacture stock entry records actual billets consumed, actual finished weight produced and actual scrap weight by type. ERPNext pre-fills scrap from the BOM's standard; operators must overwrite it with weighed actuals, otherwise you're just recording the standard and calling it data. Capture weights at the source Weights are where most setups fail. A weighbridge or platform scale integration is the cleanest route; where that isn't possible, a simple, mandatory entry step on the shop floor (via Job Cards or a lightweight custom form) is the next best thing. Getting this piece right is usually where a [tailored ERPNext implementation](/services/tailored-erpnext-implementation/) earns its keep, because every mill's weighing points are different. Handle kg vs pieces vs bundles Bars are produced in pieces and bundles but costed and sold by weight. Set up UOM conversions per section so dispatch can work in bundles while stock and yield stay in weight. Store theoretical weight per metre on the item so a report can compare it against actual weighed output. If you're not sure how your own mill's loss categories would map into this, that's a useful conversation to have before touching any configuration. ## Reporting: turning entries into yield variance Once the data is clean, a custom report can show, per Work Order, heat, shift or mill: Actual yield vs standard yield (from the BOM) Scrap by type, in weight and value Unexplained loss (input minus good output minus recorded scrap) Actual vs theoretical weight on finished bars The "unexplained loss" line is the most useful number on the report. When it grows, something is going unrecorded: scrap walking out, scales drifting, or entries being copied from the standard. ## Honest limitations ERPNext won't detect a miss-roll or measure scale loss on its own. It records what people and scales tell it. If the mill has no reliable weighing at input and output, software will only formalise guesses. It also isn't a mill-level control system; roll-pass design and real-time stand monitoring sit outside an ERP. What it does well is give you one ledger where billets, finished goods, scrap, cost and sales meet, so the yield conversation moves from opinion to numbers. ## Frequently Asked Questions [How is yield calculated in a steel re-rolling mill?](#collapse-1751) Yield is good finished output weight divided by input billet or ingot weight for the same run. Tracking it per heat or per shift, rather than monthly, is what makes the variance actionable. [Can ERPNext value scrap separately from finished goods?](#collapse-1752) Yes. Scrap items carry their own valuation rate, and ERPNext deducts scrap value from finished-goods cost in the Manufacture entry. The accuracy depends on keeping those rates close to real realisation. [What's the difference between scrap and process loss in ERPNext?](#collapse-1753) Scrap is material that comes out as a stock item you can sell or re-melt, such as end cuts. Process loss is material that disappears, such as scale that isn't collected. Both reduce yield, but only scrap adds stock. [Do we need a weighbridge integration?](#collapse-1754) Not strictly, but manual weight entry needs discipline and checks. Without trustworthy input and output weights, yield variance reports will mostly reflect data-entry habits. [Is a steel-specific ERP better than ERPNext for this?](#collapse-1755) Steel-specific products come with mill concepts built in. ERPNext needs configuration to reach the same point but covers accounting, sales, purchase and HR in one open-source system, which suits many small and mid-sized units. ## Next step Aavatto has been implementing ERPNext for manufacturers across India and the Middle East since 2020, and our [case studies](/case-studies/) show how we've fitted ERPNext to real shop-floor processes in other manufacturing sectors. If you want to see what yield and scrap tracking would look like for your own mill, **book a free ERPNext consultation**. We'll walk through your loss categories and weighing points and tell you plainly what ERPNext can and can't cover.