作業資源彈性與作業成本行為

Abstract

瞭解成本行為有助企業經理人員估計所做決策的影響。根據成本在攸關範圍內對產量變動所做的反應，大多數管會教科用書將成本歸分為變動成本及固定成本。該成本歸類方式有迅速提供關於成本與產量間關係的優點，然而卻無法反映作業成本(Acticity costs)乃取決於作業資源(Activity resources)的投入量而非其實際用量之事實。本研究以作業資源投入量及其實際消耗量，推導作業成本的模型並闡述在何種條件下作業成本比較可能隨產量作比率的變動。特別地，本研究以作業資源的彈性來評估作業成本與產量之間的關係。運用個案分析，本研究指出，當企業經理人員擁有較大的彈性能經常依據實際產量來調整對作業資源的投入量時，作業成本將較具變動性。

Understanding cost behavior is essential for managers to estimate the impact of their decisions . Most management accounting textbooks classify costs into variable costs and fixed costs based on their behavior in response to changes in the level of production volume within the relevant range. Such a classification of costs as variable or fixed has the advantage of providing a quick perspective of the relation between costs and production volume. But, it fails to reflect the fact that activity costs are determined by the resources committed to the activity rather than the actual usage or consumption of these resources required to support actual production. This paper explicitly models activity costs in terms of commitment and consumption of activity resources and describes conditions under which activity costs are more likely to vary in proportion to the production volume. In particular, the paper evaluates the relationship between activity costs and production volume in terms of a firm`s flexibility in adjusting the resources committed to the activity. With reference to a case analysis, this paper shows that activity costs appear more variable if managers have greater flexibility to frequently adjust the committed activity resource capacity levels in response to the demand placed on them.