A2CM-L10 — Relevant Costing
Understanding how relevant costs and revenues are identified and used to support effective management decision-making.
Learning Objectives
By the end of this lesson students should be able to:
• understand relevant costing
• distinguish relevant and irrelevant costs
• identify avoidable costs
• identify opportunity costs
• apply relevant costing to decision-making
• answer examination-style questions
Concept Framework
What is Relevant Costing?
Relevant costing is a decision-making technique that considers only costs and revenues that will change as a result of a decision.
Costs that are unaffected by the decision are ignored.
Why Use Relevant Costing?
Management uses relevant costing to:
• evaluate alternatives
• improve decision-making
• avoid misleading information
• focus on future costs and revenues
• maximise profitability
CORE TERMINOLOGY - TERM , MEANING & KEY RULES
| Term | Meaning |
|---|---|
| Relevant Cost | Future cost affected by a decision |
| Irrelevant Cost | Cost unaffected by a decision |
| Opportunity Cost | Benefit sacrificed when choosing an alternative |
| Sunk Cost | Past cost that cannot be changed |
| Incremental Cost | Additional cost resulting from a decision |
| Item | Relevant? |
|---|---|
| Future Variable Costs | Yes |
| Additional Fixed Costs | Yes |
| Opportunity Costs | Yes |
| Sunk Costs | No |
| Historical Costs | No |
| Allocated Costs Unaffected by Decision | No |
DECISION-MAKING LOGIC
Step 1
Identify available alternatives.Step 2
Identify future costs and revenues.Step 3
Exclude sunk and irrelevant costs.Step 4
Include opportunity costs where applicable.Step 5
Select the option with the greatest net benefit.
RELEVANT VS IRRELEVANT COSTS
| Relevant Costs | Irrelevant Costs |
|---|---|
| Future Costs | Past Costs |
| Opportunity Costs | Sunk Costs |
| Incremental Costs | Historical Costs |
| Avoidable Costs | Unavoidable Costs |
📌 Relevant costing is one of the most important management decision-making topics. Students should master: ✓ Relevant Cost Identification ✓ Sunk Cost Elimination ✓ Opportunity Cost Analysis ✓ Decision Evaluation ✓ Examination Presentation 🎥 Full worked examples are available in the YouTube Learning Library. 📩 Students may submit relevant costing doubts through the Student Doubt Support facility.
WORKED EXAMPLES
Example 1 — Sunk CostMachine purchased last year:
£100,000
The purchase cost cannot be recovered.
Therefore:
Sunk Cost
Not Relevant
Example 2 — Opportunity CostFactory Space
Current Rental Income:
£15,000
If used for a new project,
the rental income is lost.
Opportunity Cost:
£15,000
Relevant
Example 3 — Relevant Cost CalculationAdditional Materials:
£8,000
Additional Labour:
£5,000
Opportunity Cost:
£2,000
Relevant Cost:
£15,000
📌 Relevant costing is one of the most important management decision-making topics.
Students should master:
✓ Relevant Cost Identification
✓ Sunk Cost Elimination
✓ Opportunity Cost Analysis
✓ Decision Evaluation
✓ Examination Presentation
🎥 Full worked examples are available in the YouTube Learning Library.
📩 Students may submit relevant costing doubts through the Student Doubt Support facility.
Structured Practice
Level 1 – Concept Check
Define:
a) Relevant Cost
b) Opportunity Cost
Level 2 – Application Practice
Explain why sunk costs should be ignored when making decisions.
Level 3 – Examination Style Question
A business is considering a new project.
Additional Materials:
£12,000Additional Labour:
£6,000Existing Equipment Cost:
£40,000Lost Rental Income:
£3,000Calculate the total relevant cost.
(4 marks)
📌 Additional structured questions are available in the 🎯 Question Papers + YouTube Explanation section.
∗ Additional structured questions are available in the Question Papers and YouTube Explanation section. Students should practise regularly and review video explanations for procedural clarity.
Enrolled students may submit questions from recognised textbooks, past examination papers or other genuine academic material for expert clarification through the Student Doubt Support facility.
Proficiency Check
Learn → Practise → Analyse → Evaluate
1. Can you distinguish relevant and irrelevant costs?
2. Can you identify sunk costs correctly?
3. Can you identify opportunity costs accurately?
4. Can you calculate relevant costs for decisions?
5. Can you evaluate alternative courses of action?
6. Can you explain why only future costs are relevant?
If unsure, revisit:
• Relevant Cost Rules
• Opportunity Cost Examples
• Sunk Cost Concepts
• Worked Examples
Detailed Activity Solutions
Solution to Level 3 question
Relevant Costs:
Materials:
£12,000
Labour:
£6,000
Lost Rental Income:
£3,000
Total Relevant Cost:
£21,000
Existing Equipment Cost:
£40,000
Ignored because it is a sunk cost.
How This Topic Appears in the Examination
Common examination tasks include:
✓ Relevant Cost Identification
✓ Opportunity Cost Calculations
✓ Sunk Cost Analysis
✓ Alternative Decision Evaluation
✓ Project Selection Decisions
✓ Short-Term Management Decisions
Self-Assessment Checklist
□ I understand relevant costing
□ I can distinguish relevant and irrelevant costs
□ I can identify opportunity costs
□ I can identify sunk costs
□ I can calculate relevant costs accurately
□ I can answer examination questions confidently
Continue Your Preparation
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PREMIUM RESOURCES
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GUESS PAPERS
Prepare for the examination with complete Guess Paper packages and Mark Schemes.
VIDEO ON DEMAND
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