本论文是两位管理会计界非常有名的教授，对传统的ABC成本法进行更简单化、系统化的研究成果 ，发表于2007年12月份的哈佛商业评论，并出版了相关的书籍，相信对大家的财务成本分析工作有所帮助 。
Time-Driven Activity-Based Costing
Robert S. Kaplan and Steven R. Anderson
The traditional ABC model has been difficult for many organizations to implement because of the high costs incurred to interview and survey people for the initial ABC model, the use of subjective and costly-to-validate time allocations, and the difficulty of maintaining and updating the model as (i) processes and resource spending change, (ii) new activities are added, and (iii) increases occur in the diversity and complexity of individual orders, channels and customers.
Time-driven ABC requires estimates of only two parameters: (1) the unit cost of supplying capacity and (2) the time required to perform a transaction or an activity. A time-driven ABC model:
• can be estimated and installed quickly
• is easily updated to reflect changes in processes, order variety, and resource costs
• can be data fed from transactional ERP and CRM systems
• can be validated by direct observation of the model’s estimates of unit times
• can scale easily to handle millions of transactions while still delivering fast processing times and real-time reporting
• explicitly incorporates resource capacity and highlights unused resource capacity for management action
• exploits time equations that incorporate variation in orders and customer behavior without expanding model complexity
The paper uses simple numerical examples to articulate the fundamentals of time-driven ABC and provides several examples of companies that have implemented the approach and enjoyed rapid and significant profit improvements.
Time-Driven Activity Based-Costing
Activity-based costing was introduced in the mid-1980s through several Harvard Business School cases and articles.1 While the settings of these cases differed, they all had one characteristic in common. The resource expenses assigned to an activity were determined through interviews, time logs, and direct observation of the amount or percentage of time people spent on various activities. For example, the costs of warehousing goods would be driven to activities − such as Receiving, Inspection, Put-away, Picking, Packing, and Shipping − based on estimates by warehouse personnel of the percentage of their time they spent on each of the activities. The project team then calculated activity cost driver rates, used to assign activity costs to individual products or customers, by dividing these activity costs by the outputs of each activity − such as number of receipts, number of inspections, number of items picked, and number of shipments.
This procedure for estimating an ABC model, while feasible for initial pilot studies, has proved difficult and costly to extend to company-wide applications. Also, even after the initial model has been built, updating the model requires essentially re-estimating through a new round of interviews and surveys to reflect changes in a company’s operations. Consequently, ABC models are often not maintained and their cost estimates soon become obsolete. In this paper, we review the problems associated with traditional estimation of ABC models. We describe a new approach that is both simpler − for estimating and maintaining an ABC model − and also more accurate. The new, time-driven approach allows for more heterogeneity in activities, orders, and customer behavior without placing burdensome demands for calculating activity, product and customer costs.
Estimating a Basic ABC Model
The standard procedure for estimating a simple ABC model starts with identifying a collection of resources that perform a variety of activities. For example, consider a customer service department that performs three activities:
• handle customer orders
• process customer complaints
• perform customer credit checks.
Assume that the cost of supplying resources – personnel, supervision, information technology, telecommunications, and occupancy − to perform these activities is $560,000 per quarter. In building an ABC model for the customer service department, the system designer asks employees to estimate the percentage of their time spent (or that they expect to spend) on the three principal activities they perform. Suppose they estimate