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9609 · 9.3.1

Operational decisions — practice questions

Practice and worked examples for 9609 Operational decisions. Short previews only — attempt the full question in MarkScheme against the official scheme.

Worked example 1

Food processor faces 30% demand spike for Q4. Factory at 95% capacity utilisation. Outline operational decisions available.

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Capacity: Overtime shifts, temporary staff (2.1.3), subcontract bulk blending to approved partner.

Stock: Build finished goods buffer in Q3 if perishable allows — or increase raw material orders with JIT supplier agreement.

Maintenance: Defer non-critical maintenance risky at 95% utilisation — prioritise line reliability.

Outsource: Non-core packaging to free line capacity for high-margin SKUs.

Evaluation: Subcontract + overtime likely cheapest vs new capital (10.3) for one-season spike.

Worked example 2

AeroComponents Ltd needs 50,000 units of a specific aircraft-grade bolt annually. They can purchase it from an external supplier for $12 per unit. Alternatively, they can produce it in-house. The in-house production would incur variable costs of $8 per unit and additional fixed costs of $250,000 per year. Using quantitative analysis, advise AeroComponents on whether to make or buy the bolts.

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Step 1: Calculate the total annual cost of buying (outsourcing). This is the cost if all 50,000 units are purchased from the supplier.

  • Formula: Cost to Buy = Annual Demand × Price per unit
  • Calculation: 50,000 units × $12/unit = $600,000

Step 2: Calculate the total annual cost of making in-house. This is the sum of the variable and fixed costs for producing 50,000 units internally.

  • Formula: Cost to Make = (Variable Cost per unit × Annual Demand) + Fixed Costs
  • Calculation: ($8/unit × 50,000 units) + $250,000
  • Calculation: 400,000+400,000 + 250,000 = **650,000650,000**

Step 3: Compare costs and provide a quantitative recommendation.

  • Total Cost to Buy: 600,000600,000
  • Total Cost to Make: 650,000650,000
  • Comparison: The cost to buy is $50,000 less than the cost to make for an annual demand of 50,000 units.
  • Recommendation: Based purely on financial grounds, AeroComponents should buy the bolts from the external supplier.

Step 4: Further Analysis (Break-Even Point). To find the output level where the decision changes, we calculate the break-even quantity.

  • Formula: Break-Even Quantity = Fixed Costs / (Price to Buy - Variable Cost to Make)
  • Calculation: 250,000/(250,000 / (12 - 8)=8) = 250,000 / $4 = 62,500 units.
  • Interpretation: If annual demand were to rise above 62,500 units, making the bolts in-house would become the cheaper option. Since current demand (50,000) is below this break-even point, buying remains the more cost-effective choice.

Step 5: Qualitative Evaluation. While buying is cheaper, AeroComponents must also consider qualitative factors. For aircraft-grade bolts, quality and reliability are paramount. In-house production offers greater control over quality assurance and production schedules. The final decision involves a trade-off between the lower cost of outsourcing and the greater control offered by in-house production.