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Resources · Manufacturing Internal Audit

Manufacturing internal audit checklist.

Manufacturing internal audit needs more than a generic P2P or inventory checklist. The fieldwork has to connect material purchase, stores issue, production output, WIP, scrap, job work, capex, maintenance, statutory compliance and ERP controls into one RCM.

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RCM map

Eight areas to test areas

Production planning and BOM control

Risk: Production records, bill of material standards or yield assumptions do not reflect actual shop-floor consumption.

Controls
  • Approved BOM and routing master
  • Production order approval
  • Yield and wastage review
  • Exception approval for over-consumption
Tests
  • Compare actual material consumption with BOM standards
  • Review production orders closed without matching output
  • Test yield variance by product line
  • Inspect approval for abnormal consumption or rework
Evidence

BOM master, production orders, batch cards, yield reports, variance analysis and production manager approvals.

Stores, GRN and material issue

Risk: Materials are received, issued or returned without complete gate, GRN, inspection and requisition evidence.

Controls
  • Gate-entry to GRN matching
  • Quality inspection hold/release
  • Stores issue against approved requisition
  • Return-to-store recording
Tests
  • Match gate entry, supplier invoice, GRN and quality release
  • Sample stores issues against approved requisitions
  • Review negative stock or back-dated issue entries
  • Trace material returns to inventory records
Evidence

Gate register, GRN, QC release, stores requisition, issue slip, return note and stock ledger.

Inventory valuation and WIP

Risk: Raw material, WIP, finished goods or stores values are misstated because quantity, stage of completion, NRV or overhead allocation is wrong.

Controls
  • Periodic stock count
  • WIP stage validation
  • Costing review
  • NRV/obsolete stock review
Tests
  • Reconcile physical count to book stock by location
  • Inspect WIP stage evidence for selected batches
  • Review overhead absorption basis
  • Test obsolete, slow-moving and damaged stock provision
Evidence

Stock count sheets, inventory ageing, WIP statement, cost sheet, overhead absorption working and NRV assessment.

Job work and subcontracting

Risk: Goods sent to job workers are not tracked, not returned in time, or are incorrectly billed, consumed or treated for GST.

Controls
  • Challan-wise job-work register
  • Return ageing review
  • Job-worker reconciliation
  • Scrap/loss approval
Tests
  • Reconcile material sent, received back, transferred or supplied directly
  • Age open challans by input/capital-goods category
  • Compare job-work bills with output received
  • Review losses, waste and scrap treatment
Evidence

Job-work challans, ITC-04 support, job-worker ledger, return register, ageing report and reconciliation file.

Scrap, waste and by-products

Risk: Scrap or by-product generation is understated, sold outside books, or not reconciled to production output.

Controls
  • Scrap generation norms
  • Scrap sale approval
  • Weighbridge/gate-pass control
  • Scrap stock reconciliation
Tests
  • Compare scrap generation to production volume and norms
  • Match scrap dispatch to invoice, gate pass and receipt
  • Review cash or manual scrap sales
  • Investigate unusual product-line wastage
Evidence

Scrap register, production report, weighbridge slip, sales invoice, gate pass, receipt proof and variance notes.

Plant maintenance and downtime

Risk: Breakdowns, preventive maintenance gaps or idle capacity affect production, quality, cost absorption and delivery performance.

Controls
  • Preventive maintenance calendar
  • Breakdown log review
  • Critical spares control
  • Downtime analysis
Tests
  • Inspect PM completion against calendar
  • Review repeated breakdowns by machine
  • Compare downtime with production shortfall
  • Check critical spares issue and ageing
Evidence

PM schedule, maintenance log, downtime report, spare-parts ledger, work orders and closure sign-off.

Capex, CWIP and fixed assets

Risk: Capital expenditure is unauthorised, wrongly capitalised, left in CWIP after use, or not physically verified.

Controls
  • Capex approval matrix
  • CWIP ageing review
  • Capitalisation checklist
  • Asset tagging and physical verification
Tests
  • Sample capex against approved budget and PO
  • Review CWIP items ready for use but not capitalised
  • Inspect asset tagging and location
  • Test disposals and impairment indicators
Evidence

Capex note, PO, installation certificate, CWIP ageing, FAR, asset tags, disposal approval and physical verification sheet.

Factory statutory and EHS compliance

Risk: Factory licences, labour-law filings, pollution consents, hazardous-material controls or safety obligations are delayed or unsupported.

Controls
  • Compliance calendar
  • Licence/consent tracker
  • Incident reporting
  • Contract labour and wage compliance review
Tests
  • Review due-date tracker and filing acknowledgements
  • Check licence/consent validity
  • Inspect sample EHS incidents and closure
  • Test contractor compliance documents
Evidence

Compliance calendar, filing acknowledgements, licence copies, consent orders, incident register and contractor records.

Continuous monitoring

Rules worth automating rules

RuleException logic
BOM varianceActual material consumption exceeds standard beyond tolerance for selected SKU/batch.
Negative stockInventory item goes negative or receives back-dated stock adjustments after period close.
Open job-work challansInputs or capital goods sent to job worker remain open beyond review threshold.
Scrap anomalyScrap sale value or quantity is materially below production-linked expectation.
CWIP ageingCWIP item remains open despite installation, commissioning or production evidence.
Downtime spikeMachine downtime crosses threshold without maintenance closure or production-plan adjustment.
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Downloads

Templates and linked tools workpapers

Manufacturing Audit Workbook

Generate an Excel/PDF workbook for production, BOM, stores, inventory, WIP, job work, scrap, capex, compliance and ERP controls.

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Inventory Internal Audit Checklist

Stock movement, physical verification, ageing, write-off and valuation controls.

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Fixed Assets Internal Audit Checklist

Capex, CWIP, FAR, tagging, depreciation, disposal and physical verification controls.

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Treasury and Cash Management Audit

Useful for plant financing, bank limits, guarantees, forex and covenant monitoring.

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Job Work Register

Challan-wise register for goods sent to and received from job workers.

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Internal Audit RCM Builder

Turn this checklist into an editable RCM with test procedure and evidence columns.

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Monitoring Rules Repository

Use recurring exceptions for inventory, P2P, R2R, compliance, treasury and ITGC.

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FAQ

Manufacturing internal audit FAQs questions

What should a manufacturing internal audit cover?

A manufacturing internal audit should cover production planning, BOM and yield controls, stores and GRN, inventory valuation, WIP, job work, scrap, plant maintenance, capex/CWIP, statutory compliance, ITGC and the finance cycles that support them: P2P, O2C, R2R, payroll and treasury.

How is manufacturing internal audit different from trading or services?

Manufacturing has physical conversion risk. The auditor must connect purchase, stores issue, production output, WIP stage, scrap, finished goods, dispatch and costing. A generic purchase or sales checklist misses yield variance, job-work ageing, overhead absorption, CWIP readiness and shop-floor evidence.

Can manufacturing internal audit be monitored continuously?

Yes, selected checks work well as recurring rules: negative stock, BOM variance, open job-work challans, duplicate vendors, stale GRNs, slow-moving inventory, scrap variance, overdue compliance filings, CWIP ageing and privileged ERP access. Exceptions still require auditor review before reporting.

Which evidence is most important in a manufacturing internal audit?

The most useful evidence connects movement to source records: gate entry, GRN, QC release, stores issue, batch card, production report, stock ledger, job-work challan, weighbridge slip, FAR, maintenance log and the ERP audit trail for changes to masters or transactions.