In most small factories the goods receipt is the moment material enters the system, and the stock figure moves the instant the challan is signed. That feels efficient. It is efficient — right up to the day it is not, when three weeks of production have been planned against material that was never fit to use.
This article is about the gap between those two moments: what it costs to leave it empty, why the vendor stops cooperating when you do, and how to fill it without turning your stores into a quality lab.
Received and usable are two different events
When a consignment arrives, two separate things need to be true before it can go to the shop floor. It has to be here — the right quantity, against the right purchase order. And it has to be good — the right material, within tolerance, undamaged, with the paperwork that proves it.
The goods receipt confirms the first. Nothing in a normal gate process confirms the second. So the stock figure records something that is true (the material arrived) as though it were something else (the material is usable), and every downstream decision — the production plan, the reorder trigger, the promise to the customer — inherits the assumption.
Not a quality department, not a lab, not a certification. A defined step that sits between “it arrived” and “it can be issued”, owned by a named person, ending in a recorded decision. In a twenty-person shop that person is often the storekeeper with a vernier, a checklist and the authority to say no.
One consignment, two outcomes
Take the item from our safety stock article: an SG iron pump body from a local foundry at ₹1,450 landed. A consignment of 600 arrives — ₹8.7 lakh of castings. 4% are defective: short machining allowance on the bore and blowholes on the flange face. That is 24 pieces, worth ₹34,800.
The defect rate is identical in both versions below. The only thing that changes is where you find it.
| Caught at the gate | Found on the machine, 3 weeks later | |
|---|---|---|
| How it is found | Sample check flags the lot; all 600 are sorted | One bad casting at a time, as each bore is opened up |
| Sorting / inspection effort | ₹2,600 | — |
| Machining already spent on bad pieces | — | ₹8,784 |
| Debit note on ₹34,800 of rejects | Raised same day, undisputed | Disputed, settled at half — ₹17,400 lost |
| Shortfall on the production plan | None — the plan was never built on them | Emergency rebuy at 15% premium — ₹5,220 |
| Cost to the factory | ₹2,600 | ₹31,404 |
The machining line assumes each bad body absorbs about 0.6 hours before the defect reveals itself, at the combined labour-and-overhead rate of ₹610 an hour we worked out in the job costing article. The sorting line assumes two minutes a piece for a helper at ₹130 an hour.
₹31,404 ÷ ₹2,600 ≈ 12×
Same lot, same 24 castings. The cost of a defect is not fixed — it grows with every step of work you put into the part before you find it.
And the table flatters the machine scenario, because it leaves out the harder-to-price costs: the line standing while someone finds replacement bodies, the overtime to catch up, and the risk that one bad casting was not found at all and went out inside a finished pump.
Why the vendor stops listening
The single biggest line in that table is the debit note settled at half. Every factory owner has lived it. The foundry says the castings were fine when they left, that your machining caused the problem, that you should have complained earlier. It feels like bad faith. Usually it is not — usually the vendor has the stronger legal position, and knows it.
Indian sale-of-goods law gives a buyer the right to a reasonable opportunity to examine goods before accepting them. It also treats a buyer as having accepted goods in broadly three situations: when he tells the seller he accepts them; when he does something with them that is inconsistent with the seller still owning them; or when he keeps them beyond a reasonable time without saying he is rejecting them.
Cutting metal off a part is about as clear an example as exists of doing something inconsistent with the seller’s ownership. So is three weeks of silence. By the time you find the blowhole, you have — on paper — accepted the lot twice over. A rejection issued in writing at the gate, before anything is processed, is a different conversation entirely. This is general information, not legal advice; talk to your lawyer about any specific dispute.
That is the real reason incoming inspection pays for itself. Not because it catches every defect — it will not — but because it moves the moment of rejection to before the moment of acceptance. Everything after that point is negotiation from a weak position.
What it does to your stock figure and your plan
The rupee cost is the visible part. The quieter damage is to three numbers the rest of the factory runs on.
The stock figure
The system says 600. The usable number is 576. Every plan built on that figure is built on 24 castings that do not exist in any useful sense — and because nobody knows which 24, the error surfaces one piece at a time over three weeks, as a slow drip of shortages rather than a single visible problem. MRP will plan faithfully against whatever stock figure you give it; it cannot plan against a defect nobody recorded.
The reorder trigger
Because the stock figure is high, the reorder level is reached late. The purchase order for the next lot goes out after it should have, which is exactly the moment the current lot is running short of good pieces. Two separate problems arrive in the same week and look like one.
The supplier’s lead time
This one does the most damage because it compounds. If the clock stops when the truck reaches the gate, a lot that arrived on day 12 and failed is recorded as a 12-day delivery. The replacement that arrived on day 24 was the real one. As the safety stock article argued, lead time runs from the purchase order to the date material cleared inspection — and a factory that measures it to the gate systematically underestimates it on precisely the vendors who are least reliable, which is where the cushion needs to be biggest.
What to check at the gate
Inspection does not mean checking everything. It means checking the five things that decide whether the material is usable, and writing down which apply to which item.
Count or weigh against the invoice and the purchase order. Short supply is the most common incoming discrepancy and the easiest to catch — and the most annoying to argue about once the material has been mixed into the store.
Is it the right material? For steel, the mill test certificate and heat number are the evidence; for castings, the grade and the foundry’s test report. An EN8 bar that is actually mild steel will pass every dimensional check you give it.
Not every dimension on the drawing — the three or four that actually decide whether the part works or can be machined. For the pump body, that is bore stock and flange thickness. Write those down per item so the check does not depend on who is on shift.
Cracks, blowholes, rust, dents, damage in transit. Cheap to check, quick to record, and a photograph at the gate settles more disputes than any clause in a purchase order.
Invoice matches the PO on item, quantity and rate; GST details are right; the test certificate is attached where one is required. A document problem is not a quality problem, but it will block the payment and the input tax credit just as effectively.
How much to inspect
Checking every piece of everything is how inspection gets abandoned within a month. Effort should follow risk — the same logic as the ABC split for reorder levels, applied to quality instead of quantity.
| Level | When to use it | What it means in practice |
|---|---|---|
| Full inspection | Safety-critical parts; any new vendor for their first three lots | Every piece, every critical dimension |
| Sample inspection | Established vendors on stable items | A defined sample per lot; if it fails, sort the whole lot |
| Certificate-based | Proven vendors on certified material | Verify the test certificate every lot; physically check one lot in five |
| No formal inspection | Cheap consumables — washers, cable ties, cotton waste | Count and accept. A rejected box costs less than the paperwork to reject it. |
The level is not permanent. A vendor earns their way down the table with clean lots and falls back up it with a single bad one. That record is also the fairest basis there is for a supplier conversation — it is the vendor’s own history, not your impression of them.
When a lot fails
A failed inspection needs a decision, and it needs one person with the authority to make it. There are only three options:
- Reject the lot. Everything goes back. Right when the defect rate is high or the defect is in something you cannot sort for.
- Sort it. Check every piece, keep the good, return the bad. Right when the line needs the material and the defect rate is low — which is what happened with the pump bodies. Agree up front who pays for the sorting.
- Accept on deviation. The defect is real but does not affect function. Accept it deliberately, in writing, usually against a price reduction or a corrective-action commitment — never silently.
Whichever it is, tell the vendor in writing the same day, before anything is processed. That is the step that preserves your position.
Getting the rejects out of the building
Rejected material has a way of never leaving. It sits in a corner of the store marked “return” for three months, gets counted in the annual stock check, occasionally gets issued by someone who did not read the tag, and the debit note ages alongside it.
The fix is a returnable gate pass: the rejected quantity leaves on a document that records how much went, when, on which vehicle, with which driver and transporter. That is the physical trail behind the debit note. It turns “we sent them back” from an assertion into a record, and it gets the material out of your stock figure and your building at the same time.
Six ways this goes wrong
1 · Stock goes up the moment the challan is signed
Received and usable are recorded as one event, so everything downstream plans against material nobody has confirmed.
Cost: 600 on the screen, 576 on the shelf, and nobody knows which 24. Fix: keep received and usable as separate quantities. Nothing is issued until it is cleared.2 · Rejection happens on the shop floor
The defect is discovered by the operator, after machining, weeks after arrival — the most expensive possible time and the weakest possible legal position.
Cost: roughly twelve times the gate cost in the worked example, most of it a disputed debit note. Fix: a gate check before issue, and a written rejection before any processing.3 · Everything is inspected the same way
Either everything gets full inspection and the process is abandoned within a month, or nothing does and the critical castings go through with the cable ties.
Fix: four levels by risk, with vendors moving between them on their own record.4 · The checks live in one person’s head
The senior storekeeper knows which dimensions matter on the pump body. When he is on leave, nobody checks them.
Fix: write the critical dimensions and checks against each item, so the inspection is a property of the item rather than of the person.5 · Rejected material never leaves
It sits in a corner tagged “return”, gets counted, occasionally gets issued, and the debit note ages with it.
Cost: phantom stock, a stuck debit note, and the occasional reject in a finished product. Fix: rejected quantity leaves on a returnable gate pass, with the debit note raised against it.6 · Lead time stops at the gate
A failed lot is recorded as delivered on the day it arrived, so the vendor’s delivery record looks better than it is.
Cost: safety stock sized too small on exactly the vendors who most need a bigger cushion. Fix: measure lead time to the date material cleared inspection. A rejected lot has not been received.The routine
Goods receipt against the PO on arrival; usable only after inspection. Two quantities, never one.
The five checks, and which critical dimensions apply. Start with your top twenty purchased items by value.
Full, sample, certificate-based or none — and let vendors move between levels on their record.
Reject, sort or accept on deviation, by a named person, with a reason, communicated to the vendor before any processing.
Quantity, vehicle, driver and transporter recorded; debit note raised against it; material out of the building.
Where this lives in OEMup
Everything above can run on a register and a vernier. What a system adds is that the gap between received and usable gets its own recorded step, and that the rejection leaves a paper trail.
Receipt against the purchase order
The purchase invoice (GRN) is booked against its purchase order — delivered quantity, discounts, IGST and grand total in real time — so the quantity check against the PO happens at the point of receipt rather than at month-end reconciliation. Payment status sits in the same invoice register. It is the receipt step of the indent-to-payment flow.
The QC gate itself
OEMup’s quality inspection of incoming goods is built as exactly the step this article describes: the QC gate between goods received and usable stock. Inspections are raised from the PO invoice, and each one records approved and rejected quantities and a pass or fail with reasons — the written decision that protects your position with the vendor.
Lots that carry their inspection with them
Every stock receipt creates a lot, with traceability from receipt through inspection to dispatch. Stock is held with live on-hand and available quantities. And because the lot follows the material through to dispatch, a defect found later can be traced back to the receipt and the inspection it came from — which is what turns a rejection from an argument into evidence.
Getting rejects out: the returnable gate pass
Rejected material leaves on a Returnable Gate Pass: return quantity, driver, transporter and vehicle, a branded gate-pass PDF, and challan tracking on the way back. That is the physical trail behind the debit note — it shows what left, when and how — and it gets the rejects physically out of the store corner.
No ERP knows that bore stock and flange thickness are the two dimensions that matter on this casting, or that this foundry’s blowholes always show up on the flange face. Deciding what to check, and how hard, is engineering judgement that stays with the people who know the part. What the system does is give the inspection its own place between receipt and stock, record the decision with its reasons, and keep the gate-pass trail for everything you send back.
See one consignment go through the gate
Book a 30-minute demo and bring a real purchase order — we’ll book the receipt against it, raise the inspection, record a partial rejection with reasons, and send the rejected quantity back on a returnable gate pass, so you can see the whole path from truck to usable stock.
Book a Demo →The bottom line
Incoming inspection is not really about quality. It is about timing. The defect is in the casting whether or not you look for it; the only question is whether you find it before you have accepted the lot, or after.
Find it at the gate and it costs you a helper’s afternoon and a debit note nobody argues with. Find it on the machine and it costs you the machining, the rebuy, half the debit note, and three weeks of plans built on stock that was never there. On the worked example that is ₹2,600 against ₹31,404 — for the same 24 pieces.
If you do one thing this week, take your top ten purchased items by value and write down, for each, the two or three dimensions that decide whether the part is usable. That list is most of an inspection plan, and on most shop floors it exists only in the head of the one person who has been there longest.
Related reading: Safety Stock vs Reorder Level for why lead time has to be measured to inspection clearance, Procurement Management for the indent-to-payment flow this step sits inside, Vendor Portal Software for keeping the supplier conversation off WhatsApp, and How to Cost a Job for the machining rate behind the worked example.
FAQ
What is incoming inspection in a factory?
The check between goods arriving at the gate and those goods becoming usable stock. It confirms quantity, identity and grade, critical dimensions, visual condition and documents, and ends in a recorded decision — accept, reject, sort, or accept on deviation. Received and usable are two different events; a factory that records only the first is carrying stock it has never confirmed it can use.
How much does it cost to skip incoming inspection?
On 600 SG iron pump bodies at ₹1,450 with 4% defective — 24 pieces, ₹34,800 — catching them at the gate costs about ₹2,600 in sorting and ends in a clean debit note. Finding them on the machine costs ₹8,784 in wasted machining, ₹17,400 lost on a debit note settled at half, and ₹5,220 for an emergency rebuy: ₹31,404, about twelve times as much.
Why does the supplier dispute the debit note for defective material?
Because under Indian sale-of-goods law a buyer is generally treated as having accepted goods when he does something with them inconsistent with the seller still owning them, or keeps them beyond a reasonable time without rejecting them. Machining a casting is exactly that kind of act. Rejecting in writing at the gate, before processing, puts you in a much stronger position. This is general information, not legal advice.
What should be checked during incoming inspection?
Five things: quantity against invoice and PO; identity and grade, with mill test certificate and heat number for steel; the critical dimensions that decide whether the part works; visual condition; and documents — invoice matches PO, GST details right, test certificates attached.
Should every incoming item be inspected?
No — follow risk. Full inspection for safety-critical parts and new vendors’ first lots; sampling for established vendors on stable items; certificate-based acceptance for proven vendors on certified material; and no formal inspection for cheap consumables, where rejecting costs more than the item.
What should happen when an incoming lot fails inspection?
A named person decides: reject the lot, sort it and return only the bad pieces, or accept on deviation in writing where the defect does not affect function. Tell the vendor in writing the same day, and send the rejected quantity back on a returnable gate pass so the debit note has a physical trail.
How does incoming inspection affect supplier lead time?
Honest lead time runs from the purchase order to the date material cleared inspection, not to the date the truck reached the gate. A lot arriving on day 12 that fails has not been received; the replacement on day 24 is the real delivery. Measuring to the gate underestimates lead time on the least reliable vendors, which is where safety stock most needs to be bigger.
What is a returnable gate pass?
The document that lets material leave the factory to go back to a vendor — rejects, or items sent for repair — with quantity, driver, transporter and vehicle recorded. For rejected incoming material it is the physical trail behind the debit note, proving what left, when and how.
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