Activity-based costing

In a business organization, Activity-Based Costing (ABC) is a method of assigning the organization's resource costs through activities to the products and services provided to its customers. It is generally used as a tool for understanding product and customer cost and profitability. As such, ABC has predominantly been used to support strategic decisions such as pricing, outsourcing and identification and measurement of process improvement initiatives.

Historical development

Traditionally cost accountants had arbitrarily added a broad percentage of expenses onto the direct costs to allow for the indirect costs.

However as the percentages of indirect or overhead costs had risen, this technique became increasingly inaccurate because the indirect costs were not caused equally by all the products. For example, one product might take more time in one expensive machine than another product, but since the amount of direct labor and materials might be the same, the additional cost for the use of the machine would not be recognised when the same broad 'on-cost' percentage is added to all products. Consequently, when multiple products share common costs, there is a danger of one product subsidizing another.

The concepts of ABC were developed in the manufacturing sector of the United States during the 1970s and 1980s. During this time, the Consortium for Advanced Manufacturing-International, now known simply as CAM-I, provided a formative role for studying and formalizing the principles that have become more formally known as Activity-Based Costing.

Robin Cooper and Robert S. Kaplan, proponent of the Balanced Scorecard, brought notice to these concepts in a number of articles published in Harvard Business Review beginning in 1988. Cooper and Kaplan described ABC as an approach to solve the problems of traditional cost management systems. These traditional costing systems are often unable to determine accurately the actual costs of production and of the costs of related services. Consequently managers were making decisions based on inaccurate data especially where there are multiple products.

Instead of using broad arbitrary percentages to allocate costs, ABC seeks to identify cause and effect relationships to objectively assign costs. Once costs of the activities have been identified, the cost of each activity is attributed to each product to the extent that the product uses the activity. In this way ABC often identifies areas of high overhead costs per unit and so directs attention to finding ways to reduce the costs or to charge more for costly products.

Activity-based costing was first clearly defined in 1987 by Robert S. Kaplan and W. Bruns as a chapter in their book Accounting and Management: A Field Study Perspective. They initially focused on manufacturing industry where increasing technology and productivity improvements have reduced the relative proportion of the direct costs of labor and materials, but have increased relative proportion of indirect costs. For example, increased automation has reduced labor, which is a direct cost, but has increased depreciation, which is an indirect cost.

Like manufacturing industries, financial institutions also have diverse products and customers which can cause cross-product cross-customer subsidies. Since personnel expenses represent the largest single component of non-interest expense in financial institutions, these costs must also be attributed more accurately to products and customers. Activity based costing, even though originally developed for manufacturing, may even be a more useful tool for doing this.

Methodology
1. Cost centres
Cost centres are divisions that add to the cost of the organization, but only indirectly add to the profit of the company. Typical examples include Research and Development, Marketing and Customer service.

Companies may choose to classify business units as cost centres, profit centres, or investment centres. There are some significant advantages to classifying simple, straightforward divisions as cost centres, since cost is easy to measure. However, cost centres create incentives for managers to underfund their units in order to benefit themselves, and this underfunding may result in adverse consequences for the company as a whole (reduced sales because of bad customer service experiences, for example).

Because the cost centre has a negative impact on profit (at least on the surface) it is a likely target for rollbacks and layoffs when budgets are cut. Operational decisions in a contact centre, for example, are typically driven by cost considerations. Financial investments in new equipment, technology and staff are often difficult to justify to management because indirect profitability is hard to translate to bottom-line figures.

Business metrics are sometimes employed to quantify the benefits of a cost centre and relate costs and benefits to those of the organization as a whole. In a contact centre, for example, metrics such as average handle time, service level and cost per call are used in conjunction with other calculations to justify current or improved funding.


2. Fixed cost

In cost accounting, a part of management accounting, fixed costs are expenses that do not change in proportion to the activity of a business, within the relevant period or scale of production. For example, a retailer must pay rent and utility bills irrespective of sales. Unit fixed costs, called average fixed costs (AFC), decline with volume, following a rectangular hyperbola as the inverse of the volume of production: AFC = FC/N.

Variable costs by contrast change in relation to the activity of a business such as sales or production volume. In the example of the retailer, variable costs may primarily be composed of inventory (goods purchased for sale), and the cost of goods is therefore almost entirely variable. In manufacturing, direct material costs are an example of a variable cost. An example of variable costs are the prices of the supplies needed to produce a product.

Along with variable costs, fixed costs make up one of the two components of total cost. In the most simple production function, total cost is equal to fixed costs plus variable costs.

In microeconomics and business, the difference between fixed costs and variable costs (and the related terms average cost and marginal cost) is crucial, as each will influence production decisions for profit maximization differently. In the most simple cases, fixed costs do not affect production decisions, because they cannot be changed, and management will choose to produce if sales prices are above the cost of each additional unit (marginal cost).

Fixed costs should not be confused with sunk costs. From a pure economics perspective, fixed costs may not be fixed in the sense of invariate; they may change, but are fixed in relation to the quantity of production for the relevant period. For example, a company may have unexpected and unpredictable expenses unrelated to production, and these would not be considered part of variable costs.

It is important to understand that fixed costs are "fixed" only within a certain range of activity or over a certain period of time. If enough time passes, all costs become variable. Similarly, not all indirect costs are fixed costs; for example, advertising expenses or labour costs are indirect costs that are variable over a slightly longer time frame, as they may not be subject to change in the short term, but may be easily adjustable over a longer time frame. For example, a firm may not be able to vary the number of employees (and hence labour costs) in the short term due to contract obligations, but be able to lay employees off or otherwise change these costs.

In accounting terminology, fixed costs will broadly include all costs (expenses) which are not included in cost of goods sold, and variable costs are those captured in costs of goods sold. The implicit assumption required to make the equivalence between the accounting and economics terminology is that the accounting period is equal to the period in which fixed costs do not vary in relation to production. In practice, this equivalence does not always hold, and depending on the period under consideration by management, some overhead expenses (such as sales, general and administrative expenses) can be adjusted by management, and the specific allocation of each expense to each category will be decided under cost accounting.

In business planning and management accounting, usage of the terms fixed costs, variable costs and others will often differ from usage in economics, and may depend on the intended use. For example, costs may be segregated into per unit costs (costs of goods sold), fixed costs per period, and variable costs as a proportion of revenue. Capital expenditures will usually be allocated separately, and depending on the purpose, a portion may be regularly allocated to expenses as depreciation and amortization and seen as a fixed cost per period, or the entire amount may be considered upfront fixed costs.

3. Variable cost

Variable costs are expenses that change in proportion to the activity of a business. In other words, variable cost is the sum of marginal costs. It can also be considered normal costs. Along with fixed costs, variable costs make up the two components of total cost. Direct Costs, however, are costs that can be associated with a particular cost object. Not all variable costs are direct costs, however; for example, variable manufacturing overhead costs are variable costs that are not a direct costs, but indirect costs.Variable costs are sometimes called unit-level costs as they vary with the number of units produced.

For example, a manufacturing firm pays for raw materials. When activity is decreased, less raw material is used, and so the spending for raw materials falls. When activity is increased, more raw material is used and spending therefore rises. Note that the changes in expenses happen with little or no need for managerial intervention.

A company will pay for line rental and maintenance fees each period regardless of how much power gets used. And some electrical equipment (air conditioning or lighting) may be kept running even in periods of low activity. These expenses can be regarded as fixed. But beyond this, the company will use electricity to run plant and machinery as required. The busier the company, the more the plant will be run, and so the more electricity gets used. This extra spending can therefore be regarded as variable.

In retail the cost of goods is almost entirely a variable cost; this is not true of manufacturing where many fixed costs, such as depreciation, are included in the cost of goods.

Although taxation usually varies with profit, which in turn varies with sales volume, it is not normally considered a variable cost.

In most of the concerns, salary is paid on monthly rates. Though there may exist a labour work norm based on which the direct cost (labour) can be absorbed in to cost of the product, salary cannot be termed as variable in this case.

4. Cost driver

A Cost Driver is any activity that causes a cost to be incurred. The Activity Based Costing (ABC) approach relates indirect cost to the activities that drive them to be incurred. In traditional costing the cost driver to allocate indirect cost to cost objects was volume of output. With the change in business structures, technology and thereby cost structures it was found that the volume of output was not the only cost driver. Some examples of indirect costs and their drivers are: maintenance costs are indirect costs and the possible driver of this cost may be the number of machine hours; or, handling raw-material cost is another indirect cost that may be driven by the number of orders received; or, inspection costs that are driven by the number of inspections or the hours of inspection or production runs. Generally, the cost driver for short term indirect variable costs may be the volume of output/ activity; but for long term indirect variable costs, the cost drivers will not be related to volume of output/ activity. John Shank and Vijay Govindarajan list cost drivers into two categories: Structural cost drivers that are derived from the business strategic choices about its underlying economic structure such as scale and scope of operations, complexity of products, use of technology, etc and Executional cost drivers that are derived from the execution of the business activities such as capacity utilization, plant layout, work-force involvement, etc. To carry out a value chain analysis, ABC is a necessary tool. To carry out ABC, it is necessary that cost drivers are established for different cost pools.

Direct labour and materials are relatively easy to trace directly to products, but it is more difficult to directly allocate indirect costs to products. Where products use common resources differently, some sort of weighting is needed in the cost allocation process. The measure of the use of a shared activity by each of the products is known as the cost driver. For example, the cost of the activity of bank tellers can be ascribed to each product by measuring how long each product's transactions takes at the counter and then by measuring the number of each type of transaction.

Limitations

Even in activity-based costing, some overhead costs are difficult to assign to products and customers, for example the chief executive's salary. These costs are termed 'business sustaining' and are not assigned to products and customers because there is no meaningful method. This lump of unallocated overhead costs must nevertheless be met by contributions from each of the products, but it is not as large as the overhead costs before ABC is employed.

Although some may argue that costs untraceable to activities should be "arbitrarily allocated" to products, it is important to realize that the only purpose of ABC is to provide information to management. Therefore, there is no reason to assign any cost in an arbitrary manner.