Activity-Based Costing: Meaning, Process and Benefits

Activity-based costing (ABC) is a costing method that assigns overhead and indirect costs to products or services based on the activities that consume those resources. Instead of spreading all overheads evenly across output, ABC traces each cost to the activity that caused it, giving businesses a much more accurate picture of what each product or service actually costs to produce.

What is activity-based costing?

ABC is a type of costing method that works by identifying the specific activities involved in producing a product or delivering a service, assigning costs to those activities and allocating them to products based on usage.

Traditional costing uses a single rate, often based on machine hours or direct labour, to allocate all overheads. This can distort costs when products consume resources very differently. ABC corrects this by using multiple cost drivers, making it more suitable for businesses with diverse product lines or complex operations.

For example, a manufacturer producing both a simple bolt and a custom-engineered component may spend far more time on quality checks and machine setup for the latter. Under traditional costing, both products absorb the same overhead rate. Under ABC, the custom component bears a higher share of inspection and setup costs, reflecting its actual resource consumption.

The table below sets out the core differences between traditional costing and activity-based costing:

A worked example

Suppose total setup and inspection overhead is ₹2,00,000, spread across 1,000 bolts and 100 custom components. Under traditional costing using a single rate, each unit absorbs the same ₹181.82 (₹2,00,000 ÷ 1,100 units), regardless of actual effort.

Under ABC, the driver is the number of setups. If the custom components require 40 of the 50 total setups, they absorb ₹1,60,000 of the overhead and the bolts only ₹40,000. Each custom component now carries ₹1,600 of setup cost against ₹40 for each bolt. The custom line, which traditional costing made look cheap, is revealed as far more resource-hungry.

What are the key steps in the activity-based costing process?

Implementing ABC requires a structured approach. These are the general steps involved:

1. Identify activities: List every activity that consumes resources in the production or service delivery process. These could include machine setup, quality inspection, order processing or customer support.
2. Assign costs to activity pools: Group costs into activity cost pools. Each pool collects all the costs associated with one specific activity. For instance, all costs related to running the quality inspection process go into a single pool.
3. Determine cost drivers: A cost driver is the factor that causes a cost to be incurred. For machine setup, the cost driver might be the number of setups performed. For order processing, it could be the number of orders received.
4. Calculate activity rates: Divide the total cost in each pool by the total units of the corresponding cost driver. This gives you the cost per unit of activity.
5. Assign costs to products or services: Multiply the activity rate by the number of times each product uses that activity. Summing these across all activities gives the total overhead cost attributable to that product.
6. Analyse and act: Use the results to review pricing, identify loss-making products and find activities where costs can be reduced.

What are the advantages of activity-based costing?

ABC offers several practical advantages over conventional costing methods, particularly for businesses with varied product mixes or high indirect cost ratios.

• Accurate product costing: By tying overhead costs to actual resource consumption, ABC produces a more realistic cost per product. This prevents underpricing profitable items and overpricing others.
• Better pricing decisions: When you know the true cost of producing something, setting a price that covers costs and delivers a margin becomes far more straightforward.
• Identifying non-value-adding activities: ABC forces you to examine every activity in the business. Activities that consume cost without adding value to the customer become visible and can be reduced or eliminated.
• Improved profitability analysis: Management can assess profit margins at the product, customer or channel level rather than relying on blended averages.
• Support for strategic planning: With reliable cost data, businesses can make more confident decisions about product rationalisation, outsourcing and capacity allocation.

What are the disadvantages of activity-based costing?

ABC is not without drawbacks. Understanding these helps businesses decide whether it is the right approach for them.

• Time and cost of implementation: Identifying activities, setting up cost pools and selecting cost drivers requires significant effort. For smaller businesses, the setup cost may outweigh the benefit.
• Ongoing maintenance: Activity costs and drivers need regular review. If the business changes its processes, the cost model must be updated to remain accurate.
• Subjectivity in activity identification: Different analysts may identify different activities or choose different cost drivers for the same process, introducing inconsistency into results.
• Not suitable for every business: ABC is most beneficial when overhead costs are high and diverse. Businesses with simple, homogeneous product lines may find traditional costing adequate.

Conclusion

ABC gives businesses a more honest view of costs than blanket overhead allocation can provide. When pricing decisions are based on what products actually consume, the risk of carrying undercosted lines or walking away from profitable ones is far lower. Maintaining accurate cost data is where the discipline tends to break down over time, particularly as product mixes and processes change.

TallyPrime supports businesses in tracking costs, managing accounts and generating the financial reports that ABC analysis depends on, helping you move from raw data to reliable cost insight faster.