Activity-Based Costing: A Tool to Aid
Decision Making
Solutions to Questions
7-1 Activity-based costing differs from traditional costing systems in a number of ways. In activity-based costing, nonmanufacturing as well as manufacturing costs may be assigned to products. And, some manufacturing costs—including the costs of idle capacity--may be excluded from product costs. An activity-based costing system typically includes a number of activity cost pools, each of which has its unique measure of activity. These measures of activity often differ from the allocation bases used in traditional costing systems.
7-2 When direct labor is used as an allocation base for overhead, it is implicitly assumed that overhead cost is directly proportional to direct labor. When cost systems were originally developed in the 1800s, this assumption may have been reasonably accurate. However, direct labor has declined in importance over the years while overhead has been increasing. This suggests that there is no longer a direct link between the level of direct labor and overhead. Indeed, when a company automates, direct labor is replaced by machines; a decrease in direct labor is accompanied by an increase in overhead. This violates the assumption that overhead cost is directly proportional to direct labor. Overhead cost appears to be driven by factors such as product diversity and complexity as well as by volume, for which direct labor has served as a convenient measure.
7-3 Employees may resist activity-based costing because it changes the “rules of the game.” ABC changes some of the key measures, such as product costs, used in making decisions and may affect how individuals are evaluated. Without top management support, employees may have little interest in making these changes. In addition, if top managers continue to make decisions based on the numbers generated by the traditional costing system, subordinates will quickly conclude that the activity-based