Cellular Manufacturing Model Analysis

The objective of this paper is to present a new method of mixed-integer non-linear programming model that is conducive for layout design of a dynamic cellular manufacturing system (DCMS). During a multi-period planning horizon in a dynamic environment, the product mix and part demands vary extensively. Consequently, the cell configuration that is considered best for one period may not be efficient for the successive periods necessitating changing the configurations. There are three main and interlinked decisions involved in the design of a CMS. They are: cell formation (CF) group layout (GL) and group scheduling (GS). In this new model the CF and GL decisions are concurrently made in a dynamic environment. This model proposed by integrating

Cellular manufacturing (CM), which is a novel manufacturing method drawn from a group technology (GT) concept is an approach that can be utilized to enhance both flexibility and efficiency in the current modern manufacturing ecosystems like the flexible manufacturing systems (FMS) and Just in Time (JIT) method of production. Few advantages of CM implementation are: reduction in setup time, reduction in work-in-process inventory, reduction of costs in material handling, improvement in machine usage and quality. The design of a cellular manufacturing system (CMS) involves in (1) cell formation (CF) that is : (aggregating parts with similar requirements in processing into part families and related machines into machine cells), (2) group layout (GL) ( that is: laying out machines inside each cell, known as intra-cell layout, and cells with regard to one another, called inter-cell layout), (3) group scheduling (GS) (that is setting up part families) and (4) allocation of resources (i.e., allocating tools and human and material resources) [70]. Despite the interconnection between these decisions, almost all studies have been investigating them sequentially or independently. Even more in-depth review and analysis of mutually dependent relations between them can be found in Wu et

Disregarding new incoming products at future forces unplanned changes to the CMS and disrupts production and leads to surprise costs. Therefore, product life cycle changes should be built in the design of cells. This method is called the dynamic cellular manufacturing system (DCMS) [46] In this model, we think that the product mix or changes of demands in volume could be predicted so that a multi-period plan is feasible. The product mix indicates to a set of part types that needs to be manufactured at each planning period. An illustration of a dynamic cellular manufacturing problem during four periods is given in Fig 1. That is based on the dynamic plant layout model [47] For example X is the ideal cell arrangement in period 1with reference to the material handling cost. In period 2, changes of the product demand create changes in the optimal cellular configuration and leads to Y configuration in period 2. Likewise, because of oncoming changes in demand periods 3 and 4, the ideal cellular configuration changes to Z and Y respectively. If there is no cost in changing from one ideal setup to another, the best plan is to make use of the optimal configuration in each