Managerial Accounting and Cost Accounting
Managerial Accounting and Cost Accounting
This domain tests internal decision-support techniques: cost behaviour, cost-volume-profit analysis, relevant costing, activity-based costing, budgeting and variance analysis. Questions often require separating relevant from irrelevant costs and interpreting variances correctly.
Core rules
- Contribution margin equals sales less variable costs; it funds fixed costs and profit.
- Break-even units = fixed costs ÷ contribution margin per unit. Target-profit units = (fixed costs + target profit) ÷ contribution margin per unit.
- Relevant costs are future, incremental and differ between alternatives. Sunk costs and allocated common fixed costs are generally irrelevant.
- Activity-based costing assigns overhead using activities and cost drivers, reducing cross-subsidisation between products.
- Variances must be analysed by cause: a favourable price variance may reflect lower quality, not efficiency.
Worked example
Fixed costs are KD 120,000; selling price is KD 50; variable cost is KD 20, so contribution margin is KD 30 per unit. Break-even is KD 120,000 ÷ KD 30 = 4,000 units. To earn target profit of KD 60,000, required units are (KD 120,000 + KD 60,000) ÷ KD 30 = 6,000 units. If budgeted sales are 7,000 units, the margin of safety is 1,000 units, or 14.3% of budgeted sales.
Traps that cost marks
- Treating fixed cost per unit as constant when volume changes.
- Including sunk costs or allocated head-office overhead in a special-order decision.
- Assuming a favourable variance is always good.
- Using absorption costing for a short-term relevant-cost decision without adjusting for fixed overhead.