Cell Formation Techniques - A Study

Cellular manufacturing system has been proved a vital approach for batch and job shop production systems. Group technology has been an essential tool for developing a cellular manufacturing system. The paper aims to discuss various cell formation techniques and highlights the significant research work done in past over the years and attempts to points out the gap in research of past studies. In general, descriptive procedures can be classified into three major classes. The first class, which is referred to as part families identification (PFI), begins the cell formation process by identifying the families of parts first and then allocates machines to the families. The second class, which is referred to as machine groups identification (MGI). The third class of the descriptive procedures, which is referred to as part families/machine grouping (PF/MG), identifies the part families and machine groups simultaneously. PFI methods can be sub- classified as those based on informal systems (e.g., rules of thumb, visual examination or other criteria) and those based on formal coding and classification systems. The role of group technology (GT) codes in the context of cellular manufacturing is primarily as an aid in identifying the part families to which production cells should be dedicated. Further analysis is required before a family of parts to be manufactured in a cell, and the machines, which will comprise that cell, can be specified. MGI procedures consider the CF problem as a two- stage process where in the first stage of their analysis, machines are grouped based on information available in part routings and then in the second stage, parts are allocated to machine groups. When a CF approach attempts to group parts into part families and machines into machine groups simultaneously, then such an approach can be classified as PF/MG. Burbidge (1971) proposed one of the earliest PF/MG descriptive approaches for the CF problem which is referred to as Production Flow Analysis (PFA). PFA is a technique, which analyses the information given in route cards to form cells. A manual method for CF called "Nuclear Synthesis" is proposed where manufacturing cells are created around "key machines". E1-Essawy (1972) proposed a method called Component Flow Analysis (CFA) at about the same time. In some respects, the methodology of CFA does differ from that of Burbidge's PFA procedure since the latter first partitions the problem, whereas the former does not.