Inventory & warehouse module
Inventory and warehouse management tracks stock quantities, values, and movements across locations. It ensures product availability, optimises storage, and integrates with procurement, sales, and manufacturing. Advanced modules include lot traceability, bin locations, and cycle counting.
1. Inventory fundamentals
The module maintains a real‑time record of all stock items: raw materials, work‑in‑progress, finished goods, and MRO (maintenance, repair, operations). Key data: item master (SKU), unit of measure, storage conditions, and ABC classification.
2. Stock valuation methods
ERP supports multiple costing methods that affect the general ledger and profit calculations:
- FIFO First In, First Out – oldest stock used first.
- LIFO Last In, First Out – newest stock used first (less common, restricted in some IFRS).
- Weighted average Average cost after each receipt.
- Standard cost Predetermined cost; variances analysed.
The chosen method automatically posts inventory transactions to the general ledger (e.g., cost of goods sold).
3. Warehouse structure & putaway
Modern ERPs include warehouse management system (WMS) features:
- Locations / bins: Aisle, rack, shelf – enables precise putaway and picking.
- Putaway rules: Based on size, velocity (e.g., fast‑movers near shipping).
- Barcode / RFID integration for mobile scanning.
4. Stock movements & transactions
Every inventory change is recorded as a transaction with audit trail:
| Transaction | Description |
|---|---|
| Goods receipt (GRN) | Stock increase from purchase order |
| Goods issue | Stock decrease (sales, production consumption) |
| Transfer | Move between warehouses or bins |
| Adjustment | Corrections (damage, loss, cycle count) |
5. Cycle counting & physical inventory
Instead of annual shutdowns, cycle counting audits a subset of items continuously. ERP generates count sheets by location or SKU, and variances are automatically posted after approval. Common methods: ABC counting (A items counted more frequently).
6. Traceability (lot/batch & serial numbers)
Essential for pharmaceuticals, food, and electronics. ERP tracks:
- Lot/batch: For expiry management and recalls.
- Serial number: Individual unit tracking for warranty and service.
Traceability works both forward (which customers received a specific lot) and backward (which suppliers provided components).
7. Replenishment & reorder points
The module calculates when to reorder based on:
- Min / max levels
- Reorder point = (daily usage × lead time) + safety stock
- Demand forecasting (integrated with analytics)
Purchase requisitions can be generated automatically.
8. Integration with other modules
| Module | Integration point |
|---|---|
| Procurement | Goods receipt updates inventory and triggers AP invoice matching. |
| Sales / CRM | Inventory commits stock to sales orders; shipment reduces stock. |
| Manufacturing | Raw materials consumed; finished goods received. |
| Finance | Inventory value posts to GL; COGS calculated. |
Key Takeaways
- Inventory module provides real‑time stock visibility across locations.
- Supports multiple valuation methods (FIFO, average, standard).
- Warehouse management features (bin locations, putaway) improve efficiency.
- Lot/serial traceability is critical for compliance and recalls.
- Integration with procurement, sales, and manufacturing automates workflows.
What is a stockout and how does ERP help? Stockout occurs when demand exceeds supply. ERP sets reorder points and provides demand forecasts to prevent it.
Can I manage multiple warehouses? Yes, modern ERPs support multi‑warehouse, multi‑location with transfer orders.
What is ABC analysis? Classification of inventory by value/importance: A (high value, low volume), B (moderate), C (low value, high volume). Used to focus control efforts.
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