Dents and Scratches from Stacking: What Customer Returns Are Really Costing You (₹)
What do dents and scratches from stacking really cost when the customer finds them? As of 17 Oct 2026, on our illustrative assumptions, 0.3% handling damage on 50,000 parts a month means 150 damaged parts worth ₹22,500. One complaint about them costs about ₹94,000 in sorting, rework, scrap, freight and fees.
Last checked: 20 Oct 2026
By the Mama Editorial Team. For owners of machining, die-casting, plating and pressing units supplying auto Tier-1s and OEMs from Manesar, Pune-Chakan, Hosur and Sanand. Our earlier pieces priced a steady in-house rejection rate and one PPM escalation from a process failure. This one is about good parts that arrive dented because of how they were dropped, stacked, lifted and shipped.
Key takeaways
- The parts are the small line. In the worked example, the 150 damaged parts are worth ₹22,500; the complaint costs about ₹93,600, roughly four times that.
- Handling damage has no suspect window. A broken tool starts and stops at known times. A bin without separators damages every lot packed in it, so the customer treats all stock packed the same way as suspect.
- Published manuals make packaging the supplier's job. IMS-CS's supplier guideline says "Parts may not be damaged or scratched by the handling", and MANN+HUMMEL's manual raises a complaint for packaging and labelling issues too.
- You cannot quietly change the packaging. TI Fluid Systems' PPAP instruction makes tested, approved packaging part of the part approval, and MANN+HUMMEL holds a supplier liable for "all associated costs" of an unauthorised change.
- Separators can cost less than one complaint. In our assumptions, partitions for the whole bin fleet cost about ₹75,000 once.
- Cameras do not see dents. Video may show where parts are tossed, stacked or forked roughly; Mama treats rough-handling detection as a capability still being tested, with no promise.
Why handling damage is a different kind of defect
A process defect has a start and an end. A tap breaks at 3 pm and a first-off check catches it at 7 am; if you can prove those two times, the customer sorts one shift's output. That is the argument of our PPM escalation piece.
Handling damage does not work like that. The cause is a method: metal parts dropped onto metal parts at the machine, bins filled without layer pads, an overfilled bin whose lid presses the top layer, a forklift that sets pallets down hard, a truck where crates rub for 300 km. The method was the same yesterday and last month, so the honest answer to "which lots are affected?" is "all lots packed this way": the customer's store, stock in transit and your finished-goods area.
The second difference is the fix. Handling damage often needs a packaging change, and packaging is usually part of the approved product, so the fix itself needs the customer's approval.
What published supplier manuals say about packaging and damage
The published manuals we read (checked 20 Oct 2026) put the burden on the supplier.
TI Fluid Systems makes packaging part of the part approval. Its PPAP submission review and approval work instruction requires, under logistics, packaging and labels, "Verification that the packaging was tested and approved" and the same for contingency packaging (TI Fluid Systems PPAP work instruction).
MANN+HUMMEL (Global Supplier Manual MHG-PU-M-0008, Rev. 2, July 2025) makes containment within 24 hours mandatory on a complaint: identify all affected batches and shipments, sort or replace suspect parts, and put 100% inspection and special labelling on further shipments (MANN+HUMMEL Global Supplier Manual). A packaging or labelling issue raises a complaint, though only the non-conforming packaging units count toward PPM.
Its charge-back clause makes the supplier pay for sorting, rework and scrap, additional freight charges and "customer charges"; the rest of that list is covered in our PPM escalation piece. Changes need approval before they are made, and a supplier whose unauthorised change hurts MANN+HUMMEL or its customers is responsible for "all associated costs".
IMS-CS, a connector maker, publishes a handling and packaging guideline for its suppliers (RL-CS-03b, version 06). It says "Parts may not be damaged or scratched by the handling", and that the number of parts per packaging unit must be set so they "cannot be deformed or otherwise damaged during packing and transport" (IMS-CS guideline).
No public packaging or handling guideline from ACMA, the Indian auto-component association, was found on acma.in or in a web search (checked 17 Oct 2026). The document that binds you is the one in your own supply agreement.
Where parts get dented between machine and customer
Handling damage clusters at a few points.
| Point in the flow | What typically happens | What usually stops it |
|---|---|---|
| Machine unloading | Operator drops the finished part into a steel bin onto other parts | Chute, padded tray or placing by hand into a fixed position |
| WIP between operations | Parts heaped on the floor or in crates without layers, waiting for the next machine | Layer pads, quantity limit per crate, fixed WIP racks |
| Inspection and packing | Parts re-tipped from crate to crate; bins overfilled so lids press the top layer | Standard pack quantity, partitions, a fill line on the bin |
| Internal transport | Hand trolleys on broken floor; forklift tines touching crates; hard set-downs | Smooth aisles, pallet bases, a set-down rule |
| Stacking in FG store | Crates stacked above the rated height; uneven stacks lean and shift | Stack-height marking, racks for heavy crates |
| Loading and transit | Crates loose in the truck body; rubbing over long routes | Strapping, dunnage, full-load blocking |
| Returnable bins coming back | Chips, broken partitions and grit left inside | Clean-and-check step before reuse |
The common thread is metal touching metal under weight or vibration. Forklift handling is also a people-safety topic; our forklift and pedestrian safety piece covers that side.
Worked example: one handling-damage complaint, priced
Every figure below is an assumption for illustration unless a source is named. Replace each with your own numbers.
The supplier and the part. Assume a Manesar unit machines an aluminium cover with a sealing face, ₹150 a piece, 50,000 pieces a month (₹75 lakh of sales). Assume 0.3% of parts get handling damage between the machine and the customer's line: 150 parts a month.
The complaint. Assume the customer's line finds dented sealing faces in week three, rejects the lot and asks for containment. Because the cause is the packing method, it treats all stock as suspect: 20,000 pieces in its store, 5,000 in transit and 8,000 in your FG area.
Wage rate. Assume ₹650 a day for a semi-skilled worker (₹16,900 a month over 26 days; illustrative). Take the current notification for your trade from your state labour department (Haryana Labour Department). Over 8 hours that is ₹81.25 an hour; assume about 35% more for employer contributions, bonus and leave, so about ₹110 an hour.
Other rates (assumed). Third-party sorting agency at ₹300 per sorter-hour all-in. Visual sorting at 400 pieces per sorter-hour. Re-facing a scratched sealing face: 3 minutes on a VMC at an assumed ₹900 machine-hour rate, plus 1 minute of re-inspection.
| Cost line | Working (assumed unless sourced) | ₹ |
|---|---|---|
| Third-party sorting at the customer (store + transit) | 25,000 pcs ÷ 400/h = 62.5 h × ₹300, plus ₹8,000 mobilisation | 26,750 |
| Own sorting of FG stock | 8,000 pcs ÷ 400/h = 20 h × ₹110 | 2,200 |
| Rework: re-face 90 scratched parts | 90 × (3 min at ₹900/h + 1 min at ₹110/h) ≈ 90 × ₹47 | 4,230 |
| Scrap: 60 dented parts | 60 × (₹150 − ₹10 scrap value) | 8,400 |
| Return freight and express replacement lot | one trip each way | 12,000 |
| Customer incident/administration fee | flat fee per complaint | 25,000 |
| Your quality engineer at the customer, 1 day | travel and stay | 6,000 |
| 8D and packaging trial team time | 20 h × ₹450 blended | 9,000 |
| Total for one complaint | ≈ 93,580 | |
| Value of the 150 damaged parts | 150 × ₹150 | 22,500 |
One complaint costs about ₹93,600, or 1.25% of that part's monthly sales, about four times the value of the damaged parts. The incident fee line is an assumption; MANN+HUMMEL's published manual lists costs to be charged back but prints no fixed fee.
If it repeats. Assume the old packing carries on for three months while the new one is approved: about ₹2.8 lakh. A complaint every month for a year: about ₹11.2 lakh, plus escalation costs: in MANN+HUMMEL's manual a repeated complaint can trigger an escalation level, at the supplier's expense.
The fix, priced. Assume 300 bins in rotation and a reusable plastic partition set at ₹250 per bin: ₹75,000 once, plus a chute and a fill-line rule that cost little. On these assumptions the fix pays for itself before the second complaint.
Left out: the scorecard hit, any customer line stoppage and lost business at the next sourcing round. Use the PPM escalation cost calculator for the escalation side and the rework cost calculator for the in-house side.
How a returned lot hits your PPM
PPM is rejected parts per million delivered, counted by the customer's rules. If the customer counts only the 150 damaged parts against 50,000 delivered, that is 3,000 PPM for the month.
Tenneco India's published rules show how much worse it can get. If the plant returns a defective batch, "100% of returned batch" counts, adjustable to the real defective count "if supplier responds with good results, within a reasonable time". If the supplier replaces 100% of the defective batch within 24 hours, the count is 1% of the replaced batch; after 24 hours, 10% of the returned quantity (Tenneco India manual, section C 3.2).
Under rules like these, one returned lot of 5,000 counts as 100,000 PPM in a month of 50,000 deliveries. A replacement within 24 hours brings it to 50 parts, or 1,000 PPM. Fast containment beats arguing about whose truck did it.
What to change this month
- Set a standard pack quantity for each part and draw a fill line inside the bin.
- Add separators or layer pads where parts touch each other, starting with sealing faces, plated and painted parts.
- Put a chute or padded tray at machine unloading, so finished parts are placed, not dropped.
- Write to the customer before changing packaging. Most manuals treat packaging as part of the approved product; a quiet change can itself be a non-conformance.
- Log handling damage separately from process defects in your rejection ledger.
What cameras can show, and what they cannot
Limits first. A shop-floor camera does not detect a dent or a scratch on a part. Whether a scratch is within the drawing's limits is a question for inspection under proper lighting, or a dedicated vision station, not for CCTV.
| Question | Can general-purpose video answer it? |
|---|---|
| Is this part dented or scratched? | No |
| Are finished parts dropped into bins at the machine, or placed? | Sometimes, if the unloading point is in view; being tested, not promised |
| Do crates sit stacked above the marked height, or in aisles for hours? | Often, if the store and aisles are in view |
| When did a lot leave the gate, on which vehicle? | Yes, if dispatch is covered and clocks are right |
| Did the damage happen in our plant or in transit? | Not on its own; it can only show the condition at loading |
Keep output at station level, never ranking operators. Footage of recognisable workers is personal data under s.2(t) of the DPDP Act, 2023; tell workers in writing what is recorded and why (see the worker CCTV notice under DPDP).
Where Mama fits
Mama reads the cameras a plant already has over RTSP/ONVIF, or a few added ones, and every morning sends the owner a short plain-language note on where hours and money leaked yesterday: machines stopped, stations unstaffed, stock waiting in aisles or at dispatch. It watches machines and flows, counts people only in aggregate, and never inspects parts or ranks operators. Spotting rough handling of parts is still being tested, not promised. Mama can draw a camera plan for the unloading, store and dispatch points. Leave an email or phone in the form below.
FAQ
How much does a handling-damage complaint cost an Indian auto-component supplier? Usually several times the parts' value. In our illustrative example, 150 damaged parts worth ₹22,500 lead to a complaint costing about ₹93,600.
Who pays when parts arrive at the customer dented? Your supply agreement decides. IMS-CS's published guideline says parts may not be damaged or scratched by handling, and MANN+HUMMEL's manual charges sorting to the supplier.
Why does the customer sort all my stock for a few dented parts? Because a packing method damages every lot packed that way. Unlike a tool breakage, there is no start and end time that would limit the suspect quantity.
Can I change to better packaging without telling the customer? Check your manual first. TI Fluid Systems' published PPAP instruction makes tested, approved packaging part of the part approval, and MANN+HUMMEL's manual makes a supplier pay "all associated costs" of an unauthorised change.
Can cameras find dented parts? No. Ordinary factory cameras cannot see a dent or a scratch on a part. At best they show how parts are handled, stacked and dispatched, and Mama treats even that as still being tested.