Strategic Cost Management · Activity Based Cost Management

Steps in Implementing ABC and the Cost Hierarchy

Updated 11 October 2026 · Fact-checked

Implementing ABC means identifying activities, assigning resource costs to activity cost pools, choosing a cost driver for each pool, computing a rate per driver unit, and charging products by driver usage. The cost hierarchy classifies activities as unit, batch, product-sustaining or facility-sustaining, which shows which costs a driver can fairly trace to products.

Understand Steps in Implementing ABC and Cost Hierarchy

Traditional costing spreads overheads over products using one base, such as direct labour hours. This over-costs high-volume simple products and under-costs low-volume complex ones. Activity Based Costing (ABC) fixes this by tracing overheads to the activities that cause them, and then to products according to how much of each activity a product uses.

Building an ABC system follows a logical chain. You list the main activities (for example, machine setups, material handling, inspection, order processing). You group the costs of resources (salaries, power, depreciation, rent) into activity cost pools. For each pool you select a cost driver, the factor that causes the cost to rise or fall. You divide the pool cost by the total driver volume to get a cost driver rate. Finally you charge each product with rate × driver units it consumes.

A good cost driver has a clear cause-and-effect link with the cost, is easy to measure, and data for it is available at reasonable cost. Drivers are of two kinds. A transaction driver counts how many times an activity happens (number of setups, number of orders). A duration driver measures the time taken (setup hours, inspection hours). Use a duration driver when the same activity takes very different time for different products.

The cost hierarchy sorts activities by the level at which they occur. Unit-level activities are done for every unit made (machine hours, power for running machines). Batch-level activities are done for each batch, whatever its size (setups, batch inspection, material movement per batch). Product-level (product-sustaining) activities support a product line as a whole (design, engineering changes, product testing). Facility-level (business-sustaining) activities support the whole plant (building rent, plant management, security).

The hierarchy matters because unit, batch and product-level costs can be traced to products with suitable drivers. Facility-level costs have no real driver. They are either left unallocated, or spread arbitrarily, for example on a unit-level base. Say so in your answer. ABC benefits include more accurate product costs, better pricing and mix decisions, and visibility of non-value-adding activities. Typical problems are the cost and time of data collection, resistance to change, subjectivity in choosing activities and drivers, and the arbitrary treatment of facility-level costs.

Key rules to remember

Cost driver rate: Cost driver rate = Total cost of activity pool ÷ Total volume of cost driver; Use the practical or budgeted driver volume the question gives. Calculate one rate per pool.
Overhead assigned to a product: Overhead charged = Σ (Driver rate of pool × Driver units used by the product); Add across all pools. Divide by units produced to get overhead per unit.
Cost per batch-level driver: Cost per setup = Total setup cost ÷ Total number of setups; Batch costs depend on the number of batches, not on units per batch.
Cost hierarchy: Unit-level → Batch-level → Product-level → Facility-level; Only the first three are normally traced to products by drivers. Facility-level costs have no causal driver.
Driver types: Transaction driver = count of events; Duration driver = time taken; Choose a duration driver when activity time differs widely between products.

How to solve Steps in Implementing ABC and Cost Hierarchy questions

Use this sequence for both theory and numerical questions on ABC implementation and hierarchy.

1Read the data and list the activities and the cost given for each. If costs are given by resource, group them into activity cost pools first.
2Classify each activity as unit, batch, product or facility level. Write the level next to each pool.
3Choose a cost driver for each pool. Give a one-line reason that shows cause and effect.
4Compute the driver rate for each pool as pool cost ÷ total driver volume.
5Multiply each rate by the driver units used by each product, and total the overheads per product.
6Add direct costs, then divide by units to get cost per unit. Compare with the traditional figure if asked.
7State what the comparison shows (cross-subsidy, over-costing or under-costing) and give a clear recommendation.
8For theory parts, add benefits, limitations and the treatment of facility-level costs.

Quickest way: Table-and-rate shortcut

When to use it: Use this for numerical questions with 3-4 activities and 2-3 products in limited time.

Draw a small table with pools as rows and products as columns.
Write the rate beside each pool before touching products.
Fill driver units for each product, multiply by the rate, and total each column.
Check that the column totals add up to the total overhead being absorbed. If facility costs are left out, the total will fall short by that amount.
Write the level (U, B, P or F) beside each pool in one word, which usually earns the hierarchy marks.

Common mistakes in Steps in Implementing ABC and Cost Hierarchy

Treating setup cost as a unit-level cost and driving it by machine hours.
Students stay in the traditional habit of using one volume base.
Fix: Setups happen per batch. Use number of setups or setup hours, and classify them as batch-level.
Dividing pool cost by units produced instead of total driver volume.
The word 'rate' is confused with a per-unit cost.
Fix: Always divide by the total quantity of the driver, such as total orders or total inspection hours. Convert to per unit only at the end.
Allocating facility-level costs to products using a causal-sounding driver.
Students want every rupee absorbed.
Fix: State that facility-level costs have no cause-and-effect driver. Leave them out or spread them arbitrarily and say so, as the question directs.
Mixing up product-level and batch-level activities.
Both are not tied to units made, so they look alike.
Fix: Ask what triggers the activity. A batch triggers batch-level costs. Existence of the product line triggers product-level costs, such as design.
Writing the steps of implementation in the wrong order, for example choosing drivers before identifying activities.
Memorising points without the logic.
Fix: Remember the chain: activities, cost pools, drivers, rates, product costing.
Listing only benefits and ignoring problems when asked to evaluate ABC.
ABC is presented as the better method.
Fix: Give both sides: accuracy and decision usefulness against cost of data collection, complexity and arbitrary facility cost treatment.

Worked examples

Example 1

Classify each of the following activities of a plant under the ABC cost hierarchy and suggest a suitable cost driver: (a) machine power consumption, (b) machine setups for each production run, (c) engineering design of Product X, (d) factory building rent.

Show the solution

Power consumed varies with every unit's machine running time, so it is unit-level. Driver: machine hours.
Setups occur once per production run whatever its size, so they are batch-level. Driver: number of setups (or setup hours if durations differ).
Design of Product X supports the product line irrespective of units or batches, so it is product-level. Driver: number of engineering change orders or design hours for the product.
Building rent supports the whole plant and does not vary with any product, so it is facility-level. No true driver exists. Leave it unallocated or spread it arbitrarily.

Answer: (a) Unit-level, machine hours; (b) Batch-level, number of setups; (c) Product-level, design hours or change orders; (d) Facility-level, no causal driver.

Example 2

Sharma Components Ltd makes two products. Overheads: setup cost ₹2,40,000 and inspection cost ₹1,60,000. Product A: 4,000 units, 20 setups, 100 inspection hours. Product B: 1,000 units, 60 setups, 300 inspection hours. Compute overhead per unit for each product under ABC, and compare with absorption on units produced.

Show the solution

Total setups = 20 + 60 = 80. Setup rate = ₹2,40,000 ÷ 80 = ₹3,000 per setup.
Total inspection hours = 100 + 300 = 400. Inspection rate = ₹1,60,000 ÷ 400 = ₹400 per hour.
Product A: setups 20 × 3,000 = ₹60,000; inspection 100 × 400 = ₹40,000. Total ₹1,00,000. Per unit = ₹1,00,000 ÷ 4,000 = ₹25.
Product B: setups 60 × 3,000 = ₹1,80,000; inspection 300 × 400 = ₹1,20,000. Total ₹3,00,000. Per unit = ₹3,00,000 ÷ 1,000 = ₹300.
Check: ₹1,00,000 + ₹3,00,000 = ₹4,00,000, which equals ₹2,40,000 + ₹1,60,000.
Traditional: total overhead ₹4,00,000 ÷ 5,000 units = ₹80 per unit for both products.
Comparison: the traditional method under-costs Product B (₹80 against ₹300) and over-costs Product A (₹80 against ₹25).

Answer: ABC overhead per unit: Product A ₹25, Product B ₹300. Traditional method gives ₹80 for both, so Product A subsidises Product B. Review B's price and mix.

Exam tips

In theory questions, give the implementation steps in order and add one line of explanation for each. A bare list loses marks.
For the hierarchy, always give an example activity and a driver for each of the four levels.
In numerical questions, show the driver rate for each pool separately and check that the total absorbed equals the total overhead.
Close with a decision comment, such as repricing a product or dropping a non-value-adding activity. This is what the examiner wants in a strategic cost management answer.
In MCQs on drivers, ask whether the activity is triggered per unit, per batch or per product. That decides the answer.

Practice questions from Activity Based Cost Management

Steps in Implementing ABC and Cost Hierarchy in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Steps in Implementing ABC and Cost Hierarchy: frequently asked questions

What are the steps in implementing ABC?

Identify the activities, assign resource costs to activity cost pools, select a cost driver for each pool, calculate the driver rate, and charge products based on their driver usage. Many answers also add a first step of getting management support and a final step of reviewing the results.

What is the difference between batch-level and product-level activities?

Batch-level activities occur each time a batch is processed, so their cost depends on the number of batches. Product-level activities support a product line as a whole, such as design or testing, and do not depend on units or batches.

How do I choose a cost driver in ABC?

Pick the factor that causes the activity cost to change, that can be measured easily, and for which data is available at reasonable cost. Use a transaction driver when each event consumes similar resources, and a duration driver when the time taken varies widely.

How should facility-level costs be treated in ABC?

They support the whole plant and have no cause-and-effect driver. They are usually not traced to products, or are spread on an arbitrary base such as direct labour hours. State the choice clearly in your answer.