Imagine Rajesh & Co. Pvt. Ltd. manufactures ready-made garments. They need fabric — too little and the factory stops; too much and money is locked up in a dusty warehouse. Inventory management is the art of finding that sweet spot: holding just enough stock to keep operations running without bleeding cash.
At the heart of inventory management is the Economic Order Quantity (EOQ) — the order size that minimises the total of two costs that pull in opposite directions. Carrying costs (also called holding costs) rise as you hold more stock: think storage rent, insurance, spoilage, and the opportunity cost of money locked in inventory. Ordering costs fall as you order in bigger, less frequent batches: think paperwork, freight, and inspection charges per order. EOQ is the quantity where these two costs are exactly equal, and the formula is: EOQ = √(2 × Annual Demand × Ordering Cost per Order ÷ Carrying Cost per Unit per Year). This is a guaranteed numerical in the exam — practise it until it's muscle memory.
Beyond EOQ, you need to know the stock level formulas. Reorder Level = Maximum Consumption × Maximum Lead Time — this tells you when to place the next order. Minimum (Safety) Stock = Reorder Level − (Normal Consumption × Normal Lead Time) — your buffer against supply delays. Maximum Stock Level = Reorder Level + EOQ − (Minimum Consumption × Minimum Lead Time). Danger Level = Minimum Consumption × Emergency Lead Time — below this, the factory may stop. The exam loves asking you to compute these in sequence, so always solve them top-down: Reorder → Minimum → Maximum.
Two broader tools round out this topic. ABC Analysis classifies inventory: 'A' items are high-value, low-volume (tight control, frequent review); 'B' items are moderate; 'C' items are low-value, high-volume (loose control, bulk ordering). Just-in-Time (JIT) is the philosophy of ordering stock only when needed, eliminating carrying costs entirely — great in theory, but it requires reliable suppliers and is a common 2-mark theory question. This entire topic typically appears as a 5–8 mark numerical or a mix of a short numerical plus a theory part on ABC/JIT.