Incremental Analysis Examples
Work through scenario-based incremental analysis examples that compare decision alternatives, identify relevant costs and benefits, show the calculations, and explain the management decision.
Formula Reference
| Decision type | Formula | Management interpretation |
|---|---|---|
| Relevant cost test | Relevant cost or benefit = future amount that differs between alternatives | Use the amount only when it changes the decision comparison. |
| Special order | Incremental profit = special-order revenue − incremental costs − opportunity cost | Accept when the result is positive and qualitative concerns are acceptable. |
| Make or buy | Cost advantage = cost to buy − avoidable cost to make | Positive advantage favors making; negative advantage favors buying. |
| Keep or drop | Effect of dropping = avoidable fixed costs + contribution margin from alternatives − lost segment contribution margin | Drop only when the net effect improves total profit. |
| Sell or process further | Incremental profit = additional revenue from processing further − additional processing costs | Use only costs and revenues after the decision point. |
| Constrained resource | CM per constrained resource unit = unit CM ÷ constrained resource required per unit | Prioritize the highest ratio first, within demand limits. |
Relevant = Future + Different
Irrelevant = Sunk OR same under all alternatives
Opportunity Cost = Benefit given up by choosing one alternative and anotherLive Scenario Dashboard
Live Scenario Values
The dashboard values below drive the worked examples in the LO sections. Generate a new set of values to recalculate every sample problem.
| Decision area | Scenario values | Computed result |
|---|---|---|
| IA LO 3: Special order | ||
| IA LO 4: Make or buy | ||
| IA LO 5: Keep or drop | ||
| IA LO 6: Sell or process further | ||
| IA LO 7: Constrained resource |
Core rule: A relevant cost or benefit must occur in the future and differ between alternatives. The dashboard applies that rule across several short-term decision types.
IA LO 1 Examples: Describe the Five Steps in the Decision-Making Process
The five-step decision process is a structured comparison among alternatives. Incremental analysis is both a calculation and a way to decide which alternative creates the best future result.
Worked sample problem using the live scenario
Decision question: A company has a one-time order opportunity. Which alternative should management choose?
| Decision step | Alternative A | Alternative B | Alternative C |
|---|---|---|---|
| 1. Identify the decision problem | Should the company reject the order, accept the smaller order, or accept the larger order with extra cost? | ||
| 2. Determine the alternatives | Reject the order. | Accept units. | Accept units with an incremental setup cost. |
| 3. Evaluate costs and benefits | Build the incremental comparison below. Only amounts that differ between alternatives belong in the table. | ||
| 4. Make the decision | |||
| 5. Review results | Compare actual revenue, actual variable costs, capacity effects, and customer impact against the expected result. | ||
Show the work: incremental comparison
The analysis below shows how the decision is calculated. Rejecting the order is the baseline, so Alternative A has no incremental revenue or incremental cost.
| Line item | Formula | A: Reject | B: Smaller order | C: Larger order |
|---|---|---|---|---|
| Incremental revenue | Units × special-order price | |||
| Incremental variable cost | Units × unit variable cost | |||
| Opportunity cost | Units × lost regular contribution margin, if capacity is full | |||
| Incremental setup cost | Additional fixed cost caused only by this alternative | |||
| Incremental profit | Revenue − variable cost − opportunity cost − setup cost |
Calculation detail
Decisioning:
Procedure note: Treating the process as a checklist and a comparison. Step 3 is the heart of the analysis because it shows what changes across alternatives.
IA LO 2 Examples: Define and Identify Relevant Costs and Benefits
A relevant cost or benefit must occur in the future and differ between alternatives. Differential costs, incremental costs, useable costs, and opportunity costs are relevant when they meet those tests. Sunk costs and common fixed costs that remain unchanged are usually irrelevant.
Worked sample problem using the live scenario
Decision question: Which costs and benefits are relevant when comparing the three order alternatives?
| Item | Alternative A: Reject | Alternative B: Smaller order | Alternative C: Larger order | Relevant? |
|---|---|---|---|---|
| Incremental revenue | Relevant because it differs. | |||
| Variable manufacturing cost | Relevant because it changes with units accepted. | |||
| Opportunity cost | ||||
| Unuseable fixed overhead | Same | Same | Same | Irrelevant because it does not differ. |
| Incremental setup cost | Relevant when it occurs only for one alternative. |
Decisioning:
Procedure note: Labeling a whole cost type as relevant or irrelevant. Relevance depends on whether the amount changes between the specific alternatives being considered.
IA LO 3 Examples: Analyze a Special-Order Decision
A special-order decision evaluates whether a one-time order increases short-term profit. With idle capacity, the relevant costs are usually variable costs and any incremental fixed costs. With full capacity, opportunity cost must also be included.
Special-order effect = Incremental revenue - Incremental variable costs - Opportunity cost - Incremental fixed costsWorked sample problem using the live scenario
Decision question: Which special-order alternative creates the best short-term financial result?
| Line item | A: Reject order | B: Accept smaller order | C: Accept larger order |
|---|---|---|---|
| Incremental revenue | |||
| Variable manufacturing cost | |||
| Opportunity cost | |||
| Incremental setup or delivery cost | |||
| Incremental profit |
Decisioning:
Procedure note: Comparing the special-order price to full product cost. The decision depends on incremental revenue, incremental costs, and opportunity cost.
IA LO 4 Examples: Analyze a Make-or-Buy Decision
A make-or-buy decision compares useable internal production costs with outside purchase costs. Fixed costs are relevant only if useable. Released capacity can create an opportunity benefit if it can be used elsewhere.
Worked sample problem using the live scenario
Decision question: Should the company make the component internally or buy it from an outside supplier?
| Line item | A: Make internally | B: Buy from supplier | C: Buy and use freed capacity |
|---|---|---|---|
| Relevant production or purchase cost | |||
| Opportunity benefit from freed capacity | |||
| Net relevant cost |
Decisioning:
Procedure note: Including unuseable fixed costs in the make alternative or ignoring a profitable use of capacity freed by buying.
IA LO 5 Examples: Analyze a Keep-or-Drop Decision
Keep-or-drop decisions compare the effect of continuing, dropping, or restructuring a segment. Segment margin matters more than net income after common fixed cost allocations.
Segment Margin = Sales - Variable Costs - Direct Fixed CostsWorked sample problem using the live scenario
Decision question: Should management keep, drop, or restructure the segment?
| Line item | A: Keep segment | B: Drop segment | C: Restructure segment |
|---|---|---|---|
| Segment margin retained or lost | |||
| Related product contribution effect | |||
| Direct fixed cost savings | |||
| Incremental effect versus keeping |
Decisioning:
Procedure note: Dropping a segment because allocated common fixed costs create a reported loss. Common fixed costs usually remain after the segment is dropped.
IA LO 6 Examples: Analyze a Sell-or-Process-Further Decision
Sell-or-process-further decisions compare additional revenue from further processing with additional processing costs. Costs incurred before the decision point are sunk and irrelevant.
Process further if additional revenue exceeds additional processing costs.Worked sample problem using the live scenario
Decision question: Should the company sell now, process all units further, or process only part of the output?
| Line item | A: Sell now | B: Process all units | C: Process selected units |
|---|---|---|---|
| Additional revenue | |||
| Additional variable processing cost | |||
| Additional development cost | |||
| Incremental profit |
Decisioning:
Procedure note: Including prior manufacturing costs or joint costs. Only costs and revenues that occur after the decision point belong in the comparison.
IA LO 7 Examples: Prioritize Products with Constrained Resources
When a resource is constrained, managers should rank products by contribution margin per unit of the constrained resource, not by sales price or unit contribution margin alone.
CM per constrained resource unit = Unit CM / Resource units required per product unitWorked sample problem using the live scenario
Decision question: Which ranking rule should management use when machine minutes are limited?
| Product | Unit CM | Minutes per unit | CM per minute | Units if ranked correctly |
|---|
| Alternative ranking rule | Decision logic | Why it wins or fails |
|---|---|---|
| A: Rank by sales price | Prioritize the product with the highest selling price. | Fails because sales price ignores variable cost and resource usage. |
| B: Rank by unit CM | Prioritize the product with the highest contribution per unit. | Can fail because it ignores bottleneck minutes required per unit. |
| C: Rank by CM per machine minute | Prioritize the product that earns the most per constrained resource unit. | Wins because machine minutes are the bottleneck. |
Decisioning:
Procedure note: Ranking products by unit contribution margin and contribution margin per constrained resource unit.
References
Datar, S. M., & Rajan, M. V. (2026). Horngren's cost accounting: A managerial emphasis. Pearson. https://www.pearson.com/en-us/subject-catalog/p/horngrens-cost-accounting/P200000012609
Garrison, R. H., Noreen, E. W., Brewer, P. C., & Montague, N. R. (2026). Managerial accounting. McGraw Hill. https://www.mheducation.com/highered/product/managerial-accounting-garrison.html
OpenStax. (2022). Principles of Accounting, Volume 2: Managerial Accounting. Rice University. https://openstax.org/details/books/principles-managerial-accounting
Whitecotton, S., Libby, R., & Phillips, F. (2025). Managerial accounting (2025 Release). McGraw Hill.