ADDITIONAL ASPECTS OF PRODUCT COSTING SYSTEMS
Changes from Tenth Edition
Chapter 18 was modified to include discussions of customer-related and business-related cost drivers and recent evidence about the usage and success of activity-based cost systems.
Our treatment of job costing and process costing is as brief as we can make it and still get the general points across. Students do need to understand the general idea of these cost accumulation procedures; otherwise they are unable to visualize how costs are actually collected. The details, however, are appropriately left for an advanced course. The principal pedagogical problem here is how to get across the idea of equivalent production in process costing. Some introductory texts omit this idea, but this strikes us as dangerous because some student is almost sure to ask what happens in a process cost system if not all the units are completed by the end of the period. If the answer is not in the text, the instructor either has to duck the question, or attempt the difficult task of explaining it on the spot. In the text and in most problems, we assume that units are 50 percent completed as to labor and overhead. Since this assumption is widely used in practice, we see no point in complicating the text by introducing other percentages.
Certainly, the most difficult part of this chapter is the section on development of overhead rates. In our experience, mastery of this material greatly reduces the omnipresent problems students have later with production overhead variances. We also find in this regard that students need to be referred back to the text section, “Why Overhead Rates Are Predetermined,” especially in later discussions of the overhead volume variance. We have placed emphasis on the flexible overhead budget to help minimize these learning difficulties.
We feel that the new section on ABC provides the appropriate level of depth for a required course. Students need to understand the potential benefits of ABC as well as that it are not a panacea. It is important for students to realize that ABC is a decision-support model rather than a transaction processing system.
Wilkerson Company is a simple activity-based costing case. It requires students to calculate the costs of three products using on a new set of cost drivers, to compare those costs with those calculated using traditional direct labor-based allocation bases, and then to understand what the numbers mean. (This is a new case with the Eleventh Edition.)
Huron Automotive Company gives practice in computing and using costing rates and shows the differences that result from different definitions of cost centers. It also has two optional questions involving differential analysis, for the instructor who wishes to keep emphasizing that full costs are not used for all cost-related management decisions.
Siemens Electric Motor Works (A) effectively helps students discover the key concepts and potential benefits of ABC. (If an additional case is desired, we suggest the John Deere case cited in footnote 17.)
Dakota Office Products requires students to understand the mechanics of customer profitability analysis and then to use the information for strategic decision making purposes. (This is a new case with the Eleventh Edition.)
Problem 18-1: Elliott Company
a. Overhead rate =
b.| Work in Process Inventory| 22,500| |
| Raw Materials Inventory| | 6,000|
| Direct Labor| | 6,600|
| Production Overhead (6,600 x $1.50)| | 9,900|
c.| Overhead absorbed @ $1.50/direct labor hour| $9,900| | | Actual overhead| 9,550| |
| Overabsorbed| $ 350| |
Problem 18-2: Ryan Corporation
| | Cost Center|
| | __A__| __B__| __C__|
(a)| Heat, light, power| $24,000| $ 8,000| $8,000| (b)| Depreciation:| | | |