The cellular manufacturing layout problem

Most of the techniques for the cell design (CD) problem in cellular manufacturing (CM) consider only the machine-part incidence matrix as the input. They then convert this matrix into a block diagonal form to create a dedicated and independent cell for each part family, without laying out machines. Yet due to the lack of information on the layout, hence the lack of information on the performance of the shop floor, the benefits of CM cannot be validated. Furthermore, operational issues, e.g. scheduling, have an effect on the CD. However, current techniques are not comprehensive enough for a complete CD which should consider the aforementioned issues as a whole. This paper proposes a two-phase method based on total manufacturing lead time (MLT) reduction to overcome these drawbacks. In the first phase, the system is simulated by considering all of the operational issues under the assumption of zero material handling times to minimize total MLT. Besides minimized total MLT, the first phase also yields the waiting times of parts and the volume of the parts-flow between machines, which are used to find similarity measures between machines in the second phase. The second phase then exploits an algorithm which creates and uses these similarity measures to construct a layout by locating machines with higher similarity next to each other to justify the assumption of minimal total MLT and to minimize total material handling time.