Cost Terms, Concepts, and Classifications
1. Identify and give examples of each of the three basic manufacturing cost categories.
2. Distinguish between product costs and period costs and give examples of each.
3. Prepare an income statement including calculation of the cost of goods sold.
4. Prepare a schedule of cost of goods manufactured.
5. Understand the differences between variable costs and fixed costs.
6. Understand the differences between direct and indirect costs.
7. Define and give examples of cost classifications used in making decisions: differential costs, opportunity costs, and sunk costs.
A. General Theme. Costs can be classified in a number of ways—depending on the purpose of the classification. For example, classification of costs for purposes of determining inventory valuations and cost of goods sold for external reports differs from the classification of costs that would be carried out to aid decision-making. It is important to note that the classifications of costs are not mutually exclusive. That is, a particular cost may be classified in many different ways—depending on the purpose of the classification.
B. Cost Classifications for Preparing External Financial Statements. This section of the chapter focuses on the problem of valuing inventories and determining cost of goods sold for external financial reports. Before beginning this discussion, you may want to explain the difference between a manufacturing and a merchandising company. Manufacturing companies convert raw materials into a product. The company then sells that product either to other companies or, less commonly, directly to individuals. “Manufacturing” includes restaurants, movie studios, and other service-type companies as well as the more obvious examples of manufacturing such as automobile and clothing production. Merchandising companies, by contrast, buy finished products and resell the products to customers. Valuing inventories and determining cost of goods sold is simple in a merchandising company, but is difficult in a manufacturing company. For that reason, we concentrate on manufacturing in this section of the chapter.
1. Manufacturing costs. These costs are incurred to make a product. Manufacturing costs are usually grouped into three main categories: direct materials, direct labor, and manufacturing overhead.
a. Direct materials. Direct materials consist of those raw material inputs that become an integral part of a finished product and can be easily traced into it. Examples include the aircraft engines on a Boeing 777, the Intel processing chip in a personal computer, and the blank video cassette in a pre-recorded video.
b. Direct Labor. Direct labor consists of that portion of labor cost that can be easily traced to a product. Direct labor is sometimes referred to as “touch labor” since it consists of the costs of workers who “touch” the product as it is being made.
c. Manufacturing Overhead. Manufacturing overhead consists of all manufacturing costs other than direct materials and direct labor. These costs cannot be easily and conveniently traced to products. Examples include miscellaneous supplies such as rivets in a Boeing 777, supervisors, janitors, factory facility charges, etc.
d. Prime versus Conversion Costs. Prime cost consists of direct materials plus direct labor. Conversion cost consists of direct labor plus manufacturing overhead.
2. Non-manufacturing costs. A manufacturing company incurs many other costs in addition to manufacturing costs. For financial reporting purposes most of these other costs are typically classified as selling (marketing) costs and administrative costs. Marketing and administrative costs are incurred in both manufacturing and merchandising firms.
a. Marketing Costs. These costs include the costs of making sales, taking customer orders, and delivering the product to customers. These costs are also referred to as order-getting and order-filling costs.
b. Administrative Costs. These costs include all executive, organizational, and clerical costs that are not classified as production or marketing costs.
3. Period vs. product costs. Costs can also be classified as period or product costs.
a. Period Costs. Period costs are expensed in the time period in which they are incurred. All selling and administrative costs are typically considered to be period costs. You should be careful to point out that the usual rules of accrual accounting apply. For example, administrative salary costs are “incurred” when they are earned and not necessarily when they are paid to employees.
b. Product Costs. Product costs are added to units of product (i.e., “inventoried”) as they are incurred and are not treated as expenses until the units are sold. This can result in a delay of one or more periods between the time in which the cost is incurred and when it appears as an expense on the income statement. Product costs are also known as inventoriable costs. The discussion in the chapter follows the usual interpretation of GAAP in which all manufacturing costs are treated as product costs.
4. Inventory valuations and Cost of Goods Sold. In a manufacturing company, raw materials purchases are recorded in a raw materials inventory account. These costs are transferred to a work in process inventory account when the materials are released to the production departments. Other manufacturing costs—direct labor and manufacturing overhead—are charged to the work in process inventory account as incurred. As work in process is completed, its costs are transferred to the finished goods inventory account. These costs become expenses only when the finished goods are sold. Period expenses are taken directly to the income statement as expenses of the period.
5. Schedule of Cost of Goods Manufactured. Because of inventories, the cost of goods sold for a period is not simply the manufacturing costs incurred during the period. Some of the cost of goods sold may be for units completed in a previous period. And some of the units completed in the current period may not have been sold and will still be on the balance sheet as assets. The cost of goods sold is computed with the aid of a schedule of costs of goods manufactured, which takes into account changes in inventories. The schedule of cost of goods manufactured is not ordinarily included in external financial reports, but must be compiled by accountants within the company in order to arrive at the cost of goods sold. You should take some time to explain the cost of goods manufactured schedule since it is often difficult for students to understand.
C. Cost Classifications to Describe Cost Behavior. Managers often need to be able to predict how costs will change in response to changes in activity. The activity might be the output of goods or services or it might be some measure of activity internal to the company such as the number of purchase orders processed during a period. In this chapter, nearly all of the illustrations assume that the activity is the output of goods or services. In later chapters, other measures of activity will be introduced.
While there are other ways to classify costs according to how they react to changes in activity, in this chapter we introduce the simple variable and fixed classifications. A variable cost is constant per unit of activity but changes in total as the activity level rises and falls. A fixed cost is constant in total for changes in activity within the relevant range. (Just about any cost will change if there is a big enough change in activity. Fixed costs do not change for changes in activity that fall within the “relevant range.”) When expressed on a per unit basis, a fixed cost is inversely related to activity—the per unit cost decreases when activity rises and increases when activity falls.
There is some controversy concerning the proper definition of the “relevant range.” Some refer to the relevant range as the range of activity within which the company usually operates. We refer to the relevant range as the range of activity within which the assumptions about variable and fixed costs are valid. Either definition could be used—our choice was dictated by our desire to highlight the notion that fixed costs can change if the level of activity changes enough.
D. Cost Classifications for Assigning Costs. Managers often want costs to be assigned to “cost objects” such as products, customers, departments, etc. for pricing or other purposes. A direct cost is a cost that can be conveniently and easily traced to a particular cost object. Indirect costs are everything else. A cost would be considered indirect for one of two reasons: either it is impractical or it is impossible to trace the cost to the cost object.
1.Common costs. For example, it is impossible to trace the factory managers’ salary in a multi-product plant to any particular product made in the plant. Even if a product were dropped entirely, we would ordinarily expect the factory manager’s salary to remain the same. This is an example of a “common cost” and later in the text we emphasize that such costs should not be allocated for decision-making or performance evaluation purposes.
2.Variable indirect costs. On the other hand, other costs are treated as indirect costs because it would not be practical to treat them otherwise. For example, it would be possible to measure the precise amount of solder used on each circuit board produced at a HP plant, but it wouldn’t be worth the effort. Instead, solder would typically be considered an indirect material and would be included in overhead.
E. Cost Classifications for Decision-Making. Every decision involves choosing from among at least two alternatives. Only those costs and benefits that differ between alternatives are relevant in making the selection. This concept is explored in greater detail in the chapter on relevant costs. However, decision-making contexts crop up from time to time in the text before that chapter, so it is a good idea to familiarize students with relevant cost concepts.
1. Differential Costs. A differential cost is a cost that differs between alternatives. The cost may exist in only one of the alternatives or the total amount of the cost may differ between the alternatives. In the latter case, the differential cost would be the difference between the cost under one alternative and the cost under the other. Differential costs are also called incremental costs. Differential costs and opportunity costs should be the focus of decision-making. They are the only relevant costs and all others should be ignored.
2. Opportunity Costs. An opportunity cost is the potential benefit that is given up by selecting one alternative over another. The concept of an opportunity cost is rather difficult for students to understand because it is not an actual expenditure and it is rarely (if ever) shown on the accounting books of an organization. It is, however, a cost that must be considered in decisions.
3. Sunk Cost. A sunk cost is a cost that has already been incurred and that cannot be changed by any decision made now or in the future. Since sunk costs cannot be changed and therefore cannot be differential costs, they should be ignored in decision making. While students usually accept the idea that sunk costs should be ignored on an abstract level, like most people they often have difficulty putting this idea into practice.