These articleinvestigatesthe fundamental principles of the Activity Based Costing Model (TDABC) as a proper instrument for allocating the costs to cost objects and compare it with the former costing models. The implementation of traditional Activity Based Costing Model (ABC) has been very difficult for many organizations because of using costly and subjective procedures for appraisal of time allocations, maintaining and making up-to-date of model. These factors caused that this model couldn't plays as a up-to-date, on time and effective management instrument. In TDABC, We just need to estimate two parameters: the unit cost of supplied capacity and the consumption of capacity (unit times) by the activities. In addition to solving the problems of traditional Activity Based Costing Model, TDABC enables to measure idle capacity and can help managers in evaluating performance of departments by calculating of idle capacity's cost.