Sistemas de costes basados en las actividadesActivity Based Costing vs. Time-Driven ABC, una evidencia empírica

Abstract

For more than three decades now, Cost Accounting and Management Accounting have been modifying their approaches and tools to adapt to the new information needs required by the organizations. At the end of the eighties of last century, some works appeared that made clear the shortcomings of traditional cost systems to face decision making with guarantees in the new context. From the perspective of several years, we can affirm that these works marked a turning point in the field of these disciplines. The reflection process started in this period has brought as a consequence the development of numerous research lines and the resulting appearance of many calculation and cost management techniques and tools. Among these techniques, our interest is focused on activity-based models that, from different perspectives, have established a new approach that proposes not only a new costing, but also the organizations planning, control and management through their activities. Within this new perspective, the Activity-Based Costing (ABC) model is the consequence of the revision required for the cost determination models. The proposed process overcomes the shortcomings of traditional approaches and it provides objectivity and precision, notably improving the costing process. As a consequence, this model became the absolute protagonist both in the academic field, giving rise to a significant number of contributions, and also in the business framework, attracting the attention of many professionals. Nevertheless, some years after its appearance, the model has generated some doubts since its theoretical approach, apparently unappealable, has not reached the expected results from a practical implementation point of view. Several works demonstrate that Organizations have not generalized the ABC cost calculation procedure and, many of those that implemented this model, eventually abandoned it or reduced its application to particular areas. This situation has led to the appearance, less than one decade ago, of a correction that has been named Time Drive Activity Based Costing, which is presented as the definitive revision of Activity-Based approaches, at least with regard to Costs calculation. In this thesis we have put into practice both the Activity-Based Costing and the Time-Driven Activity-Based Costing models, with the aim of reviewing these models both from a theoretical and practical point of view. The implementation has been conducted in a Company from Extremadura that already used a traditional cost calculation system, thus allowing the comparison of the results with this model too. Based upon experience, and being conscious of the fact that it is only one case, we have tried to review the concepts that conform the theoretical framework of these models, the process and tools employed in the production cost calculation, as well as the utility, advantages and limitations of its practical implementation. Finally, we have tried to create a diagnosis for the current situation and future perspectives of cost assignment models based on the activity concept, with the aim of certify the current state of the art and help to orientate future research on this field.