Investigations on the performance of process cellular and virtual cellular layouts and proposal of part mix similarity coefficient for their selection

Abstract

During the last two decades, several researches were carried out in facilities layout planning considering static product mix and deterministic demand. Layout design and configuration is one among these tools and their effectiveness was successfully demonstrated in improving the organizational efficiency. The change in the manufacturing scenario necessitates new trends in layout configuration. This research work makes an attempt to study the performance of functional layout (FL), cellular layout (CL) and virtual cellular layout (VCL) to select an appropriate layout configuration for different demand conditions and part varieties using simulation based approach. To demonstrate the concept, various manufacturing systems have been modelled in WITNESS 2006 simulation software. Design of Experiments (DoE) was used in order to plan the simulation experiments considering different input parameters. The performance measures, namely throughput, average percentage utilization of machines, average work in process (WIP), average flow time, average distance travelled by part types and intra-cellular/inter-machine movement of parts, were used for evaluating the layouts. From the simulation studies, the behaviour of all the three layout types under dynamic demand conditions was observed. Though the layout performances have been studied elaborately, it was observed that a guideline is required for choosing a layout based on some criteria. It was identified that the decision on layout type based on part mix can be appropriate. To verify the behaviour of the proposed model, a comprehensive example was solved by a branch- and-bound (BandB) method with the LINGO 11.0 software and the virtual cells were formed. Thus, in this research work, guideline has been suggested for suitable layout selection based on part mix similarity co-efficient and also separate guidelines have been formulated for industries which follow cellular and virtual cellular layouts. newline newline newline