Uses and Limitations of ABC costing

1. More accurate product costs — by charging overheads through the activities that cause them, ABC avoids the distortion of a single volume-based rate, so complex low-volume products are no longer under-costed. 2. Better pricing and decisions — knowing each product's true cost allows prices to be set that genuinely cover costs, and supports sound decisions on which products to make, promote or drop. (Cost control via managing activities is also valid.)

1. Costly and time-consuming — identifying activities and drivers, collecting data and maintaining the system requires time, expertise and resources. 2. Difficulty/subjectivity in choosing cost drivers — selecting the right driver involves judgement, and some overheads have no clear single driver, so a poor choice gives no more accuracy than absorption costing. (Some facility-level costs still need arbitrary apportionment is also valid.)

Under traditional absorption costing, a single volume-based rate can distort product costs: complex, low-volume products are under-costed and simple, high-volume products over-costed. ABC charges overheads through the activities each product causes, revealing its true cost.

With accurate costs, the business can price each product correctly: it can raise the price of a product that was being under-costed (and possibly sold at a loss) so the price covers its true cost and margin; and it can reduce the price of an over-costed product to be more competitive while still covering cost. This reduces the risk of mispricing — selling products too cheaply (eroding profit) or too dearly (losing sales) — leading to better, more profitable pricing decisions.

ABC analyses overheads by activity and identifies the cost driver behind each. This shows managers which activities (such as machine set-ups, ordering or inspections) cause the most overhead. Managers can then control overheads by managing those activities — for example, scheduling fewer, larger production runs to reduce the number of set-ups, or cutting non-value-adding activities altogether. By focusing on the causes of overheads rather than just the totals, ABC gives managers a practical means of reducing them.

ABC improves accuracy only for overheads that have a clear cost driver — an activity that causes them. However, some overheads are facility-level costs, such as factory rent, rates or the managing director's salary, which are not caused by any specific product activity and have no meaningful cost driver. These must still be apportioned on an arbitrary basis (e.g. floor area or output), just as under absorption costing. So ABC reduces, but does not eliminate, the arbitrary element in overhead allocation.

For ABC: the manufacturer makes a wide range of products with high and varied overheads — exactly the situation where a single volume-based absorption rate distorts product costs, under-costing complex products and over-costing simple ones. ABC would charge overheads through the activities (set-ups, orders, inspections) each product causes, giving much more accurate product costs. This would improve pricing, support sound product decisions (which to make, promote or drop) and aid cost control by highlighting the activities driving overheads.

Against ABC: it is costly and time-consuming to set up and run — identifying activities and drivers, collecting data and maintaining the system; it is complex; choosing drivers involves judgement; and some facility-level overheads still have to be apportioned arbitrarily.

Recommendation: because this manufacturer has a diverse product range and high, activity-driven overheads, the accuracy benefits are likely to be substantial and to outweigh the cost and complexity, improving pricing and profitability. ABC is therefore recommended, provided the implementation cost is manageable. (A simpler, low-overhead business should instead retain absorption costing.)

A business would benefit from ABC where it makes a wide range of products with different complexities and volumes, where overheads are a large proportion of total cost, and where those overheads are driven by activities (set-ups, orders, inspections) rather than just volume — especially in a competitive market where accurate pricing matters. In these conditions absorption costing distorts product costs, and ABC's greater accuracy is valuable.

A business would not benefit where it makes one product or a few similar products, where overheads are small relative to direct costs, or where overheads are mainly volume-driven (so absorption costing is already accurate enough). Here the cost and complexity of ABC would exceed the small benefit, so it is not worthwhile. The decisive factor is whether the benefit of more accurate costs justifies the cost of running ABC.

Under absorption costing, overheads are spread using a single volume-based rate, so a high-volume, simple product absorbs a large share of overhead while a low-volume, complex product absorbs relatively little — even though the complex product may cause many set-ups, orders and inspections.

For example, a low-volume specialist product might appear profitable under absorption costing. After adopting ABC, the company might find this product actually causes a disproportionate number of activities, so its true cost is much higher — possibly exceeding its selling price, making it loss-making. Conversely, a high-volume standard product previously thought barely profitable might be shown to be very profitable once it stops bearing other products' activity costs.

As a result, ABC could change the company's product decisions: it might raise the price of the specialist product, redesign it to need fewer activities, promote the genuinely profitable standard products, or discontinue products that ABC reveals to be unprofitable. So more accurate costs can reshape the product range to improve overall profitability.

Implementing and running ABC has a real cost — the time and expertise to identify activities and drivers, collect data, and maintain a more complex system. Its benefit is more accurate product costs, leading to better pricing, decisions and cost control. ABC is only worthwhile if the value of these improved decisions exceeds the cost of operating the system. For a diverse, overhead-heavy business the benefit is likely to exceed the cost; for a simple, low-overhead business it is not. So a cost–benefit analysis ensures ABC is adopted only where it is genuinely cost-effective.

For a single-product business, all overheads relate to that one product, so there is no need to share overheads between different products and no distortion to correct. Traditional absorption costing already charges the overheads to the single product accurately. Adopting ABC would add cost and complexity with no improvement in accuracy, so it is not worthwhile.