Changing in Costing Models from Traditional to Performance Focused Activity Based Costing (PFABC)

This article is aimed at studying changes in models and discussing and comparing the states of these changes and their advantages. Today, industry and occupation need a costing system to meet their own needs. Costing experts believe that designing a costing system is only possible by fulfilling all its needs. On this basis, they developed different costing models for different industries according to their structures and natures. The most fundamental method used for costing was traditional costing which utilizes only one cost driver for allocating overhead and caused the obtained cost price to have a great difference with the real cost price. The costing system based on Activity Based Costing was designed by Cooper and Kaplan to remove the shortcomings of traditional costing system and to allocate a cost driver suitable to any activity comparing with traditional system and to calculate the cost price according to it. However, Activity Based Costing (ABC) model is problematic to some extent for organizations because of high costs of interviewing people, using subjective and expensive approaches for evaluating time allocations and protection difficulties and updating. Then, Time Driven Activity Based Costing (TDABC) was introduced which calculates the costs based on time driver and is simpler and less expensive than Activity Based Costing model. In addition to solving some of the difficulties of ABC, this model can measure unused capacity and help managers evaluate the function of different departments. However, because of great emphasis that this system puts on "time" and due to some limitations, Namazi introduced Performance Focused Activity Based Costing system (PFABC) which has caused more flexibility in allocating costs to activities by selecting different cost drivers. This model which is an integration of Activity Based Costing and Time Driven Activity Based Costing undertakes costing during 8 stages, but the ambiguity and uncertainty in costing systems create some problems for Performance Focused Activity Based Costing