Similarity coefficient methods applied to the cell formation problem: A taxonomy and review

The initial step in the design of a cellular manufacturing (CM) system is the identification of part families and machine groups and forming manufacturing cells so as to process each part family within a machine group with minimum inter-cellular movements of parts. One methodology to form manufacturing cells is the use of similarity coefficients in conjunction with clustering procedures. In this paper, we give a comprehensive overview and discussion for similarity coefficients developed to date for use in solving the cell formation (CF) problem. More than 160 sources from premier scientific journals, conferences and books have been reviewed. Despite previous studies indicated that similarity coefficients based method (SCM) is more flexible than other CF methods, none of the studies has explained the reason why SCM is more flexible. This paper tries to explain the reason explicitly. We also develop a taxonomy to clarify the definition and usage of various similarity coefficients in designing CM systems. Existing similarity (dissimilarity) coefficients developed so far are mapped onto the taxonomy. Additionally, production information based similarity coefficients are discussed and a historical evolution of these similarity coefficients is outlined. Finally, recommendations for future research are suggested in this paper.