Pooling generating unit data for improved estimates of performance indices

The purpose of this paper is to present and explain some fundamental concepts of pooling data to improve estimators of generating unit performance indices. These concepts were developed by a Task Force of the Application of Probability Methods Subcommittee of the Power System Engineering Committee. This paper delineates the two major reasons for pooling estimators: (1) to obtain improved estimators of unit performance when the units are homogeneous; and (2) to obtain good estimators of system performance when the system contains heterogeneous units. The paper recommends the correct method for pooling in both cases.