ISA 520 · Manufacturing

Analytical Review Tool for Manufacturing

Pre-configured with manufacturing-specific thresholds, inventory and WIP ratio monitoring, and gross margin trend analysis for production environments.

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Trial Balance Data

Tip: paste tab-separated data from Excel
Account NameCategoryCY BalancePY Balance

The Auditor's Guide to Analytical Procedures Under ISA 520

Complete guide: ISA 520 requirements quick reference, decision flowchart for when to use analytical procedures vs. tests of details, industry-specific ratio checklists for 12 sectors, threshold-setting guide by risk level, sample completed working paper, common quality-review findings, and documentation checklist.

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ISA 520 Analytical Review for Manufacturing Entities

Manufacturing audits demand particular attention to the relationship between production inputs and outputs. Under ISA 520, the auditor must develop expectations that reflect the operational realities of the production environment. For manufacturing entities, this means understanding how raw material procurement, labour deployment, and overhead absorption translate into cost of goods sold and inventory movements. The gross margin percentage is the single most important analytical indicator — any shift signals changes in pricing, product mix, input costs, or production efficiency that require investigation. A manufacturing entity reporting a 2% gross margin decline on €50M revenue represents a €1M shift that almost certainly exceeds materiality and demands explanation.

Key Ratios and Metrics for Manufacturing Audits

Inventory turnover is the second critical metric. Manufacturing entities hold three distinct inventory categories — raw materials, work-in-progress (WIP), and finished goods — and each tells a different story. Increasing raw materials with stable production may signal procurement timing changes or speculative buying. Growing WIP balances could indicate production bottlenecks or changes in product complexity. Finished goods accumulation might signal demand weakness or quality issues preventing dispatch. The auditor should calculate turnover days for each category separately and compare to prior periods. Fixed asset turnover (revenue divided by net PP&E) measures capital efficiency and should remain relatively stable unless the entity has made significant capital investments or experienced capacity changes. Production overhead absorption rates should be analysed against actual production volumes — under-absorption in periods of reduced output increases COGS and reduces margins, which the auditor should verify against management's explanations.

What Drives Account Fluctuations in Manufacturing

Manufacturing revenue fluctuations are driven by volume, price, and product mix. The auditor should disaggregate revenue analysis where possible: has revenue increased because of volume growth, price increases, or a shift to higher-value products? Each driver has different implications for other financial statement lines. Volume increases should correlate with proportional increases in raw materials and direct labour. Price increases should improve gross margin without corresponding cost increases. Product mix changes affect both revenue composition and gross margin percentages. On the cost side, raw material costs are subject to commodity price volatility — steel, polymers, electronic components, and agricultural inputs can fluctuate significantly between periods. The auditor should consider whether input cost changes have been passed through to customers (maintaining margins) or absorbed (reducing margins). Energy costs are increasingly significant for manufacturing entities and may warrant separate analysis, particularly for energy-intensive processes such as smelting, kiln operations, or chemical processing.

Key Ratios to Monitor for Manufacturing

  • Gross margin
  • Inventory turnover
  • WIP ratio
  • Fixed asset turnover
  • Days inventory outstanding
  • Production overhead ratio

What Drives Account Fluctuations

Production volume changes driving raw material and labour cost fluctuations

Input cost volatility (raw materials, energy) affecting COGS composition

Product mix shifts altering gross margin percentages

Capital expenditure cycles impacting depreciation charges

Seasonal production patterns creating working capital swings

Seasonal Considerations

Manufacturing entities often show seasonal production cycles — pre-season stock build-ups cause inventory peaks, while post-season drawdowns affect COGS timing. Compare like-for-like periods and consider order book timing when evaluating revenue fluctuations.

Recommended Investigation Thresholds for Manufacturing

Account Category Threshold %
Revenue5%
Cost of Goods Sold5%
Operating Expenses10%
Current Assets10%
Equity5%

Regulatory note: Manufacturing entities with government contracts may have specific reporting requirements. Entities subject to environmental regulations should be assessed for potential provisions (IAS 37) that could affect analytical review expectations.

Worked Example: Manufacturing Analytical Review

A mid-size automotive parts manufacturer with overall materiality of €500,000 and performance materiality of €325,000. The 10% investigation threshold combined with the €325,000 absolute threshold creates the dual-flag system.

Overall materiality: €500,000 | Performance materiality: €325,000 | Threshold: 10%

Account PY CY Change %
Revenue — Finished Goods €23,500,000 €25,000,000 €1,500,000 +6.4%
Raw Materials Consumed FLAG €11,500,000 €12,800,000 €1,300,000 +11.3%
Direct Labour €4,050,000 €4,200,000 €150,000 +3.7%
Production Overheads €2,900,000 €3,100,000 €200,000 +6.9%
Depreciation — Plant €1,650,000 €1,800,000 €150,000 +9.1%
Admin Expenses €1,350,000 €1,400,000 €50,000 +3.7%
Inventory — Raw Materials FLAG €2,100,000 €2,800,000 €700,000 +33.3%
Inventory — Finished Goods €2,200,000 €1,900,000 €-300,000 -13.6%
Trade Receivables €3,800,000 €4,100,000 €300,000 +7.9%
PP&E Net FLAG €11,200,000 €12,500,000 €1,300,000 +11.6%
Trade Payables FLAG €2,700,000 €3,200,000 €500,000 +18.5%
Flagged Item Explanations:
Raw Materials Consumed: Increase of €1.3M (11.3%) exceeds both thresholds. Driven by 6.4% revenue growth plus 4.8% increase in steel input prices confirmed by supplier price index — consistent with management explanation.
Inventory — Raw Materials: Increase of €700K (33.3%) — flagged. Management pre-purchased raw materials ahead of announced Q1 tariff increases. Verified purchase orders and supplier communications.

Frequently Asked Questions — Manufacturing

What are the most important analytical procedures for manufacturing audits?
For manufacturing entities, the most critical analytical procedures focus on gross margin analysis (CY vs PY, by product line if available), inventory turnover by category (raw materials, WIP, finished goods), fixed asset turnover, and the correlation between revenue growth and corresponding cost movements. Any disconnect between revenue and cost trends requires investigation under ISA 520.7.
How should I set investigation thresholds for manufacturing companies?
Revenue and COGS typically warrant tighter thresholds (5%) because small percentage changes represent large absolute amounts and directly impact the core profitability metric. Operating expenses can use 10-15% thresholds. Inventory balances should use 10% given their susceptibility to valuation errors and obsolescence.
What drives gross margin fluctuations in manufacturing?
Gross margin changes in manufacturing are driven by four main factors: input cost changes (raw materials, energy), selling price changes, product mix shifts (higher vs. lower margin products), and production efficiency variations (overhead absorption, scrap rates, labour productivity). The auditor should seek disaggregated data to isolate which factor is responsible.
How do I handle seasonal production patterns in analytical review?
Seasonal manufacturers (e.g., agricultural equipment, heating systems) show predictable patterns in inventory build-up and drawdown. Compare CY to PY for the same period rather than sequential quarters. Set expectations based on historical seasonal patterns and investigate deviations from the expected seasonal profile.
Should I perform separate analytical procedures on inventory categories?
Yes. Raw materials, WIP, and finished goods each have different risk profiles and drivers. Analysing them as a single 'inventory' line masks important signals. WIP movements should correlate with production activity, finished goods with sales patterns, and raw materials with procurement cycles. An increase in one category offset by a decrease in another may net to zero but signals significant operational changes.