The Usefulness of Commonality Information in Cost Control Decisions, Accounting Review
Most cost variance investigation models have considered only one cost process at a time. However, there are many reasons why cost variances from two cost processes may be correlated and why a model which exploits these commonalities may be expected to reduce expected costs. Such a model is described in this paper, and some examples are used to illustrate the effects of different factors on the cost savings.
Magee, Robert. 1977. The Usefulness of Commonality Information in Cost Control Decisions. Accounting Review. 52(4): 869-880.