On some measures for grouping efficiency

Abstract

The problem of grouping has attracted the attention of researchers and practitioners both. They have proposed number of schemes for classification of part-types into part-families and machines into machine-cells based on machine-requirement data. Real issue lies in judging objectively the relative merit of the varying grouping solutions that are obtained from their schemes. To this end, many measures have already been suggested by several researchers. In the present paper, these measures have been summarised, and their suitability is discussed. In particular, the measure due to Chandrasekharan and Rajagopalan (Int J Prod Res 24(2):451-464, 1986) has been analysed in details. Identifying the weakness of their measure, two new efficiency measures have been proposed in the present paper that relate grouping efficiency not only with exceptional elements and voids but also with the number of groups formed and size of the grouping problem. It has been shown by taking several examples from literature that the proposed measures have much better characteristics of discriminating good groups from bad ones. © 2011 Springer-Verlag London Limited.