Kanban vs MRP-Based Delivery: How the Supply Model Affects Auto-Component Reconciliation

A Tier-1 brake-line supplier in Chennai operates a line-side kanban arrangement at Hyundai Motor India’s Sriperumbudur plant. Daily dispatches run two trucks per day to a dedicated bin location at line 2; an electronic kanban signal from Hyundai’s MES triggers each dispatch; supplier-owned stock sits in the bin until the line consumes it. At the end of October the finance controller closes the month and finds a ₹2.1 crore variance between the dispatch register and what the GST e-invoice for October billed. The dispatch register shows 18,400 units shipped against ₹3.1 crore at agreed price. The invoice billed 17,200 units against ₹2.9 crore. The gap of 1,200 units (₹2.1 crore — including buffer stock at the line) is sitting in consigned stock at Hyundai Sriperumbudur, supplier-owned, awaiting consumption. The dispatch-register entries were never revenue — and would not be until Hyundai’s line consumed them. Six months earlier the team had been raising tax invoices on dispatch and got an Income-Tax notice on output GST that did not match GSTR-2B at the OEM end. This is what happens when kanban MRP delivery reconciliation auto component India logic is collapsed into a single ERP flow without understanding the model.

Quick reference

What kanban actually is — the OEM line view

Kanban (Japanese for “signal card”) originates in the Toyota Production System and is now universal in Indian auto OE supply for high-frequency, low-variation parts. The mechanic on the OEM line:

• A bin of N parts (the standard pack quantity, or SNP — say 50 brake hoses) sits next to the assembly station.
• The line worker pulls hoses out of the bin as vehicles arrive at the station.
• When the bin empties, the worker pushes a kanban card into a collection slot (paper kanban), scans an RFID tag (e-kanban), or triggers a signal from the OEM MES to the supplier (electronic kanban).
• The supplier sees the signal, picks the next bin from its buffer stock and dispatches it to the OEM dock or directly to the line.
• The empty bin returns to the supplier as a returnable packaging unit.

The line never runs out because the cycle time of the kanban loop (supplier-side buffer + transit + OEM-side bin) is sized to be shorter than the bin consumption time. Typical Indian OE kanban loops run 4 to 24 hours.

For finance, two specific characteristics make kanban hard:

• The trigger event (kanban card or e-kanban signal) is owned by the OEM line and the OEM MES. The supplier sees it as an instruction to dispatch, but there is no IDoc, no EDI 862, no portal call-off document the supplier’s ERP can ingest. The signal is operational, not financial.
• The OEM almost never raises a per-bin GRN. The acknowledgement is the monthly consumption report — at month-end the OEM reports “we consumed 18,400 brake hoses in October” — against which the supplier bills.

What MRP actually is — the scheduled release view

MRP (Material Requirements Planning) is push-based. The OEM’s production schedule generates planning quantities (the EDI 830) and firm call-offs (the EDI 862 or portal equivalent) days to weeks ahead. The supplier sees the schedule, ships against it, and the OEM raises a GRN on receipt. Settlement runs on a periodic GST e-invoice against confirmed-received quantity. This is the model covered in detail in the EDI 830/862/856 finance primer and the model most Tier-1 brake-system or engine-component supply runs on.

Under MRP, the financial-event chain is clean: forecast → firm call-off → ASN → GRN → periodic invoice. Ind AS 115 control transfer happens at GRN. Inventory ownership transfers at GRN. The GST event is the periodic invoice against confirmed-received quantity. The Section 393(1)(k) TDS deducted by the OEM is on the conversion portion of that periodic invoice. CUM accounting governs the rolling quantity discipline (see the CUM quantity drift article).

Why kanban breaks MRP-style reconciliation

A finance team that treats kanban supply with MRP logic makes three specific errors that compound at month-end.

Error 1: revenue recognised at dispatch instead of consumption. Under kanban, dispatch moves goods from the supplier dock to the OEM plant but does NOT transfer control — the supplier still owns the inventory in the consigned-stock bin. Control transfers at consumption. A team that treats dispatch as the revenue event over-recognises by the consigned-stock buffer at month-end. Over a year, the cumulative over-recognition rolls forward but the audit shows up at year-end as a stock-at-customer-premises reconciling item.

Error 2: GST e-invoice raised on dispatch quantity. Under kanban, the supply event under GST is consumption from the consigned stock, not the movement from supplier to OEM. The dispatch movement is a Rule 55 delivery challan, not a tax invoice. Raising a tax invoice on dispatch creates output GST on quantity that has not been consumed, breaks GSTR-2B reconciliation at the OEM end (the OEM cannot claim ITC for stock that has not been consumed and is still supplier-owned), and forces a Section 34 credit-note cycle to clean up. Worse, if the consumption never happens (programme changes, model EoL with consigned stock returned), the original output GST has to be reversed entirely.

Error 3: no consigned-stock register. Generic ERP three-way matching does not maintain a daily consigned-stock balance at the OEM premises. The supplier’s inventory register shows the goods as dispatched; the OEM’s stock system does not show them as owned. Without a deliberate consigned-stock register on the supplier’s side, the stock is invisible — which is exactly how Tier-1 suppliers discover ₹2–4 crore of unbilled, unrecognised consigned stock at year-end audit.

The fix is structural, not procedural: the reconciliation engine must distinguish kanban-plus-consignment supply from MRP supply at the part-plant master level and apply the right financial-event chain for each. Cross-link: consignment and VMI reconciliation for auto components for the consigned-stock register mechanics in detail.

The bin-card cycle — kanban operational mechanics in practice

A typical Indian OE kanban loop at Hyundai Sriperumbudur or Maruti Manesar runs roughly as follows. The numbers are illustrative for a high-frequency brake-hose part with SNP 50, daily consumption ~1,500 units, and a 6-hour kanban loop:

The supplier’s reconciliation engine maintains three views simultaneously: dispatch register (signal-driven), consigned-stock register at the OEM (supplier-owned), and consumption register (from OEM monthly report). The periodic GST e-invoice ties to consumption, not dispatch. The month-end consigned-stock balance reconciles supplier inventory register to OEM-confirmed consigned stock — and any drift is a reconciliation exception.

Worked example — brake-line supplier under kanban at Hyundai Sriperumbudur

A Tier-1 supplier ships brake hoses to Hyundai Motor India’s Sriperumbudur plant on a kanban arrangement. SNP 50, daily consumption ~600 units (varies with line takt time), 6-hour kanban loop. Annual programme value ~₹14 crore. Reset 1 April, contract scheduling agreement, but the daily mechanic is e-kanban signal — not 862 firm call-off.

Daily mechanic (representative day, 15 October):

• 12 e-kanban signals from Hyundai MES through the supplier portal.
• Supplier dispatches 12 bins (600 units) under a Rule 55 delivery challan referenced to the scheduling agreement.
• Goods enter consigned-stock register at Hyundai Sriperumbudur: supplier-owned inventory.
• Hyundai line consumes 580 units that day (some buffer in bins remains).
• Daily consumption recorded in Hyundai MES.
• No revenue recognised yet, no GST event. Inventory remains on supplier books.

Monthly mechanic (October close):

• 31 days of daily dispatch and consumption.
• Hyundai issues October consumption report on 2 November: total consumed 18,400 units.
• Supplier raises consolidated GST e-invoice for October: 18,400 units × ₹1,680/unit = ₹3.09 crore + 18% GST = ₹3.65 crore gross. IRN obtained from IRP.
• Ind AS 115 revenue recognised: ₹3.09 crore against consumed quantity for October.
• Consigned-stock register at Hyundai Sriperumbudur balance: dispatched 19,000 in October − consumed 18,400 = 600-unit increase. Plus opening balance of 1,200. Closing 1,800 units. Reconciled to Hyundai consigned-stock confirmation. Inventory of 1,800 units remains on supplier books, valued at cost.

Payment mechanic (November–December):

• Hyundai pays for October consumption invoice on or around 18 November (T+50 from invoice).
• Section 393(1)(k) at 2% (payment code 1012) deducted on the conversion portion of the ₹3.09 crore invoice. Conversion portion is, say, ₹0.92 crore (after steel pass-through). TDS deducted ₹1.84 lakh. Form 26AS reflects.
• Supplier reconciles TDS deducted to invoice register and to Form 26AS. Reconciliation is clean because the invoice ties to consumption, not dispatch.

What would have broken if MRP logic had been applied:

• October output GST would have been raised on 19,000 dispatched units (₹3.19 crore + 18%) instead of 18,400 consumed.
• Hyundai’s GSTR-2B claim would be 18,400 units (consumed), creating a 600-unit ITC mismatch.
• Section 34 credit note would be required for the 600-unit over-billing.
• Section 393(1)(k) TDS deduction would not match the supplier’s TDS receivable register.
• The 1,800-unit consigned stock would be invisible on supplier books — under-stated inventory and under-reported cost.

For the cross-reference on OEM-portal mechanics, the Maruti Suzuki supplier settlement process and the Tata Motors Tier-1 supplier reconciliation guide cover the major OEM portal flows. For the sub-pillar and broader manufacturing context, see the automotive component manufacturing reconciliation sub-pillar and the manufacturing reconciliation pillar. For kanban and VMI deployment guidance across the Indian Tier-1 base, see the Automotive Component Manufacturers Association of India (ACMA).

Tax overlay — GST consumption-event timing and Section 393

GST law is unchanged by the Income Tax Act 2025 — Section 7 (supply), Section 12 (time of supply for goods), Section 17(5), Section 34 (credit notes), Rule 36(4), Rule 37 and Rule 55 (delivery challan for non-supply movement) all govern. For kanban-plus-consignment supply, the time of supply is consumption from the consignment stock at the OEM premises, not dispatch from supplier dock. Rule 55 delivery challan covers the movement from supplier to OEM (movement on approval, job-work, or consignment basis as applicable). The periodic GST e-invoice raised on consumption is the tax-invoice event.

Under the Income Tax Act 2025, the OEM deducts TDS at Section 393(1)(k) — 2%, payment code 1012 on the conversion-charge portion of the periodic consumption-based invoice. Where the kanban arrangement is structured as job-work on free-issue OEM material, Section 393(1)(a) — payment code 1002 applies on the labour conversion. The legacy Section 194C reference survives only for transitional cross-era Form 168, Form 131, Form 141 reconciliations.

For broader cross-references on TDS codes and the new payment-code register, see the TDS payment codes 1001–1092 reference and the Section 393 master guide.

What automated reconciliation changes

A finance team that runs kanban supply through generic three-way matching ends up reconstructing the consigned-stock register manually every month-end and discovering ₹2–4 crore of misclassified revenue at year-end. Purpose-built auto-component reconciliation software India treats the kanban-plus-consignment supply chain as a four-event chain — dispatch via Rule 55 delivery challan, receipt into consigned stock, consumption at the OEM line, periodic GST e-invoice against consumption — and maintains the consigned-stock balance at the OEM premises continuously. TransactIG ships 24+ industry presets including the auto-component kanban-aware preset. Customer outcomes include match-rate improvement from 51% to 88%. Build is two-to-four weeks on AWS Mumbai (ISO 27001:2022). For sub-tier procurement matching, see three-way matching software India.

Continue reading

• Automotive component manufacturing reconciliation in India (sub-pillar)
• EDI 830, 862 and 856 finance primer
• CUM quantity drift: the auto-component reconciliation problem nobody talks about
• Manufacturing reconciliation in India (pillar)