Cambridge A Level Business 9609
Inventory management
Inventory management is the balance between holding too much stock — money tied up, storage, waste — and too little, which stops production and loses sales; Just in Time and Just in Case are the two ends of that balance.
The topic is examined through definitions (buffer inventory, re-order level, lead time), reading an inventory control chart, and judging whether JIT suits a particular business — which almost always comes down to how reliable its suppliers are and how predictable its demand is.
Updated 1 October 2026
How much it is worth
Inventory management: 83 marks across 36 real Cambridge 9609 AS papers — 4.6% of the total, on 16 of the 36. How that ranks against every other 9609 topic →
Why businesses hold inventory
Inventory comes in three forms:
- Raw materials and components — waiting to be used in production.
- Work in progress — partly finished products in the production process.
- Finished products — ready to sell, held to meet orders as they arrive.
Holding it lets production run continuously, meets sudden increases in demand, protects against late deliveries, and can win bulk-buying discounts.
The costs and benefits of holding it
The costs of holding inventory are the ones questions ask you to explain:
- Opportunity cost — cash tied up in stock cannot be used elsewhere, which squeezes working capital.
- Storage — warehouse space, rent, heating or refrigeration.
- Security and insurance against theft and damage.
- Wastage and obsolescence — perishable goods spoil; fashions and technology date.
- Labour to manage, count and move it.
The cost of holding too little is the other side: stock-outs halt production, orders are lost, and customers go to competitors.
Buffer inventory, re-order level and lead time
- Buffer inventory — the minimum stock held as a safety margin against late deliveries or a demand spike.
- Lead time — the time between placing an order and receiving it.
- Re-order level — the stock level that triggers a new order, set so the delivery arrives as stock falls to the buffer.
- Maximum inventory level — the most the business will hold, once a delivery arrives.
re-order level = buffer inventory + (usage per period × lead time)
re-order quantity = maximum level − buffer inventory
Worked example: an inventory control chart
Worked example
A shop holds a buffer of 200 units and a maximum of 1 200. It sells 250 units a week and deliveries take 2 weeks to arrive. Find the re-order level and the re-order quantity, and explain what happens if a delivery takes 3 weeks.
Re-order level = 200 + (250 × 2) = 700 units — order when stock falls to 700, and 500 units will be sold during the two-week wait, leaving the 200 buffer.
Re-order quantity = 1 200 − 200 = 1 000 units — four weeks of sales.
If the delivery takes 3 weeks, 750 units are sold while waiting: stock falls to 700 − 750 = −50, so the buffer is used up and the shop runs out for part of the third week. That is the buffer’s purpose and its limit — it covers ordinary delays, not serious ones. On a chart, the same reading works: the vertical drop between peaks is the usage, the flat line at the bottom is the buffer, and the horizontal gap between the re-order point and the delivery is the lead time.
Just in Time and Just in Case
Just in Time (JIT) holds little or no inventory: materials arrive exactly when needed, and products are made to order. Just in Case (JIC) holds buffer inventory so production and sales can continue whatever happens.
| JIT | JIC | |
|---|---|---|
| Benefits | Low storage costs, cash freed for other uses, less waste and obsolescence | Never runs out, meets demand spikes, survives supply delays, bulk discounts |
| Drawbacks | Any late delivery stops production; needs frequent orders and reliable suppliers; no bulk discounts | Storage, insurance and wastage costs; cash tied up in stock |
| Suits | Reliable local suppliers, predictable demand, products made to order | Uncertain supply, sudden demand peaks, cheap-to-store goods |
Adopting JIT changes more than stock levels: it needs close supplier relationships, a flexible multi-skilled workforce and accurate information. The evaluation an examiner rewards names the specific condition in the case that makes JIT safe or dangerous for this business.
Supply chain management
Supply chain management coordinates the whole flow of materials, products and information from suppliers, through production, to the final customer. Done well it lowers costs, speeds delivery and makes JIT possible; it matters most where supply chains are long and global and a single disruption ripples through every stage.
How Cambridge asks it
On the 36 AS papers Quanta holds, 20 question parts test inventory management, on 16 of the papers (9 on Paper 1, 11 on Paper 2). The command words they open with:
- Explain × 6
- Define × 4
- Identify × 3
- Evaluate × 3
- Analyse × 3
- Calculate × 1
By tariff — each size has its own technique:
- 3 × 1-mark, 4 × 2-mark, 7 × 3-mark, 1 × 5-markShort-answer questions (2, 3 and 5 marks) →
- 2 × 8-mark8-mark 'analyse' questions →
- 3 × 12-mark12-mark 'evaluate' questions →
Terms candidates have been asked to define or explain on this topic:
JIC (Just in Case) · inventory · inventory re-order level · Just in Time (JIT) · supply chain management · buffer inventory
Common mistakes
1.Buffer inventory confused with re-order level
The buffer is the safety minimum; the re-order level is the higher point at which an order is placed.
2.JIT described as “having no stock at all” and left there
Say what it depends on — reliable suppliers and predictable demand — and what it risks if either fails.
3.Costs of holding inventory listed without application
Pick the cost that bites for this business: wastage for a florist, obsolescence for a phone retailer, storage for a furniture maker.
4.Lead time read off the vertical axis of a control chart
Lead time is time — the horizontal gap between placing an order and its arrival.
Common questions
What is buffer inventory?
The minimum stock a business holds as a safety margin against late deliveries or an unexpected rise in demand.
How do you calculate the re-order level?
Buffer inventory plus usage during the lead time. With a 200-unit buffer, sales of 250 a week and a 2-week lead time, the re-order level is 700 units.
What is the difference between JIT and JIC?
JIT holds minimal inventory with materials arriving exactly when needed; JIC holds buffer inventory in case of delays or demand spikes. JIT cuts holding costs, JIC cuts the risk of running out.
What are the costs of holding inventory?
Opportunity cost of the cash tied up, storage, security and insurance, wastage and obsolescence, and the labour to manage it.
Inventory management on real papers
The papers that leaned on it hardest, as a share of the paper. Each one has its own page on Quanta with the full topic breakdown:
Every 9609 past-paper question on inventory management
20 questions across 16 papers, 89 marks in all, newest first. Open a paper to sit it on Quanta and have these questions marked.
| Paper | Question (marks) |
|---|---|
| 9609/11/M/J/26 | Q1(a) (2) |
| 9609/21/M/J/26 | Q2(a)(i) (1) |
| 9609/22/M/J/26 | Q2(a)(i) (1), Q2(d) (12) |
| 9609/12/F/M/26 | Q3(a) (2) |
| 9609/22/F/M/26 | Q2(a)(ii) (3) |
| 9609/12/O/N/25 | Q4 (5) |
| 9609/23/O/N/25 | Q2(c) (8) |
| 9609/12/M/J/25 | Q3(a) (2), Q3(b) (3) |
| 9609/13/M/J/25 | Q3(a) (2), Q3(b) (3) |
| 9609/22/M/J/25 | Q1(a)(ii) (3) |
| 9609/22/F/M/25 | Q2(d) (12) |
| 9609/11/M/J/24 | Q1(b) (3) |
| 9609/13/M/J/24 | Q6(b) (12, choice) |
| 9609/21/M/J/24 | Q1(b)(i) (3), Q1(b)(ii) (3) |
| 9609/22/M/J/24 | Q2(c) (8) |
| 9609/22/F/M/24 | Q1(a)(i) (1) |
“Choice” marks a Paper 1 Section B essay — candidates answer one of two — so the “how much it is worth” figure above counts it at half its marks.
Practise inventory management against real mark schemes
Quanta has real Cambridge A Level Business 9609 past-paper questions, with the case study beside the answer boxes, every answer marked automatically against the published mark scheme objective by objective, and the reasoning shown — and it tracks which skills you’re missing. Free for individual students.
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