Methods of Inventory Management
Just-in-Case (JIC), also known as the buffer stock approach, involves holding extra inventory to protect against unexpected surges in demand or delays in the supply chain. This extra stock is known as buffer inventory.
This method provides a competitive advantage by ensuring the business can always meet customer needs, even during supply disruptions. It also allows the business to benefit from economies of scale through bulk purchasing.
The primary drawback is the high opportunity cost, as money spent on excess stock could have been invested elsewhere, alongside the risk of obsolescence, where stock becomes unsellable before it is used.
The Reorder Level is the specific inventory quantity at which a new order must be placed. It is calculated based on the expected usage during the lead time plus any required buffer stock.
Lead Time is the duration between placing an order and receiving the goods. Accurate lead time estimation is critical; if underestimated, the business will run out of stock before the new delivery arrives.
The Reorder Quantity is the fixed amount of stock ordered each time the reorder level is reached. This is often optimized to balance ordering costs with holding costs.
The Minimum Stock Level (Buffer) acts as a safety net, while the Maximum Stock Level represents the upper limit of storage capacity or the point beyond which holding costs become prohibitive.
| Feature | Just-in-Time (JIT) | Just-in-Case (JIC) |
|---|---|---|
| Stock Levels | Minimal/Zero | High (includes buffer) |
| Primary Goal | Efficiency & Waste Reduction | Reliability & Customer Service |
| Supplier Role | Few, highly integrated partners | Multiple, competitive suppliers |
| Risk | Production halts if supply fails | High holding costs & obsolescence |
| Cash Flow | High (low capital tied up) | Low (high capital tied up) |
Analyze the Trade-offs: When asked to evaluate an inventory method, always discuss the balance between cost and risk. A JIT system is only as strong as its weakest supplier link.
Interpret the Chart: Be prepared to identify the 'Reorder Quantity' on a graph. It is the vertical distance the stock level 'jumps' when a delivery arrives, not the distance from the x-axis.
Context Matters: JIT is often unsuitable for businesses with unpredictable demand or those relying on global shipping where lead times are long and volatile.
Common Error: Do not confuse 'Reorder Level' with 'Reorder Quantity'. The level is a trigger point (when to order), while the quantity is the volume (how much to order).