Both of the preceding reconciliations use direct labor hours (DLH) as the measure of product volume because DLH is the sole allocation base in Dual’s traditional system. Whatever the allocation base in the traditional system may be, it becomes the critical measure for assessing cost distortion. If the traditional system uses multiple bases for allocating overhead, reconciliations are much more complex, although no new principle is involved.
The final point concerning the differences of the two systems is that the precise circumstances that cause a traditional system’s cost distortion can be identified by linking the data in การแสดงที่ 13-2 to the reconciliations. There are two such circumstances.
One circumstance necessary for product cost distortion is a complex cost structure, i.e., one that entails significant amounts of non-volume-related costs. If non-volume-related costs are insignificant, the traditional system’s distortions inevitably are insignificant, because they are percentages of insignificant amounts. In Dual Company, however, the amounts of batch-level and product-level costs are clearly significant. This condition is very realistic today in the many companies that produce thousands of different products. Those companies must devote significant resources to the batch-level work of setting up, scheduling, moving, and expediting, and to the product-level work of updating product designs, designing new products, testing and correcting designs, and procuring materials and components.
The other circumstance necessary for product cost distortion is a diverse product line. A diverse product line is one in which different products consume different mixes of volume-related and non-volume-related costs. Common consumes 98 percent of volume related costs, but only 50 percent of batch-related costs and 60 percent of product-related costs. In this mix, volume-related costs are not dominant. If all products consumed the same mix, traditional costing could not distort product costs regardless of how large the non-volume-related costs are, because the distortion would be calculated as zero percent of some cost amount.