ACCT2019 Chap.5 Activity Based Costing and Management
Activity Based Costing and Management
Activity-based costing traces indirect resources through activities to products, services or customers using drivers that reflect consumption. It is designed for settings where broad averages hide diversity and create cross-subsidies. Activity-based management uses the resulting visibility to redesign processes, service levels, prices or products.
The calculation has three clean stages: define pools, calculate rates and assign costs. The decision still requires a separate test of avoidability and customer value. Driver quality matters more than the number of pools: orders, setups, inspections or support hours should explain how resources are consumed.
Unit, batch, product-sustaining and customer-sustaining work can create very different profitability patterns from a single volume rate. After assignment, managers should investigate the process behind the amount. Reducing an activity may release capacity without immediately saving cash, and dropping a customer may leave the supporting resource in place.
The management response therefore distinguishes assigned consumption, available capacity and avoidable cost. Unused capacity should be visible rather than hidden in inflated activity rates, because charging it to current work can make products appear more expensive without explaining the resource decision that created the idle amount.
The final report should point to a driver that can be changed, the capacity consequence of that change and the customer outcome that must be protected.
What this chapter covers
- 01
Resource and activity pools
- 02
Cost-driver selection
- 03
Activity-rate calculation
- 04
Product and customer assignment
- 05
Cross-subsidisation
- 06
Activity-based management action
Worked example · free
Assigning order and support activities
- +1AskSia revision weighting for this invented case. Order rate is $126,000 / 2,100 = $60 per order.
- +1Support rate is $198,000 / 900 = $220 per hour.
- +1Order cost assigned is 35 x $60 = $2,100.
- +1Support cost assigned is 40 x $220 = $8,800.
- +1Total assigned activity cost is $10,900, with support hours as the dominant driver.
Key terms
- Activity Pool
- A grouping of indirect resource costs associated with a defined activity.
- Activity Driver
- A measure used to assign activity cost according to consumption.
- Cross-subsidisation
- Cost distortion in which one cost object receives too much cost and another too little.
- Customer Profitability
- Revenue less the direct and activity costs associated with serving a customer.
- Value-added Activity
- Work that contributes to attributes a customer needs or is willing to support.
Activity Based Costing and Management FAQ
When is ABC worth the effort?
ABC is most useful when overhead is material, products or customers consume activities differently, and broad averages affect decisions. Its benefit must exceed the cost of collecting driver data, maintaining pools and helping managers use the results.
Does assigned cost equal avoidable cost?
No. Assignment measures resource consumption under the model. A decision requires identifying capacity and cash flow that will actually disappear or be redeployed. Dropping a product does not save a pool automatically if the resources remain.
How does activity-based management use the numbers?
It investigates the activity behind the cost and changes process design, order policy, service level, product design or pricing. The strongest response targets a driver and preserves customer value instead of applying a broad percentage reduction.
Exam move
Draw the resource-to-activity-to-cost-object flow before calculating. For each pool, write the total cost, total driver quantity and resulting rate, then list the driver units consumed by the product or customer. Compare an ABC assignment with one broad volume-based rate and explain which item was subsidising another.
After the numbers, write two distinct paragraphs: one on why the driver causes resource use, and another on whether capacity is avoidable for the proposed decision. Practise turning a high support assignment into a management response such as fixing a process, changing an order policy or renegotiating service.
Avoid jumping straight to customer exit, because an accounting margin can omit relationship benefits and overstate savings. Build one unit-level, batch-level and customer-sustaining pool and choose a different driver for each. Challenge every choice with a rival driver and explain which has the stronger cause-and-effect story.
Then calculate unused capacity by comparing supplied driver capacity with activity used; do not spread that idle amount automatically across current products. Use a customer example to separate product margin from order, delivery and support costs, and identify which activity creates the difference.
Finish with a benefit-cost review of the system itself: data collection, staff understanding, stability of drivers and materiality of distortion. ABC is justified when the improved decisions exceed those design and maintenance costs, not simply when it produces more detailed tables.
Working through Activity Based Costing and Management in ACCT2019? Sia is AskSia’s AI Accounting tutor — ask any ACCT2019 Activity Based Costing and Management question and get a clear, step-by-step explanation grounded in how ACCT2019 is taught and assessed. Read this chapter free, then take your hardest questions to Sia.