Design of flexible plant layouts

Abstract

In this paper, we address the problem of designing flexible plant layouts for manufacturing facilities where product demands are subject to variability. A flexible layout is one that maintains low material handling costs despite fluctuations in the product demand levels. We extend existing procedures for design of flexible layouts by (1) explicitly capturing the stochastic nature of product demands and the resulting variability in material flows between different processing departments, (2) allowing for the possibility of multiple processing departments of the same type to exist in the same facility, and (3) letting material flows between pairs of individual departments be determined simultaneously with the layout and as a function of demand scenarios. Optimal and heuristic methods are presented for generating flexible layouts and determining flow allocations under various design and operation assumptions.-2-

Next Generation Factory Layouts: Research Challenges and Recent Progress

“…Montreuil et al [58] has suggested a maximally distributed, or holographic, layout where functional departments are fully disaggregated into individual machines which are then placed as far from each other as possible to maximize coverage. Benjaafar [13] has shown that, while some disaggregation and distribution is desirable, full disaggregation and distribution is rarely justified. In fact, the benefits of disaggregation and distribution are of the diminishing type with most of the benefits achieved with having only few duplicates of each department (see section 4.1).…”

“…The approach described in (b) is more promising since it attempts to build inherent features into the layout that enable it to adapt to changes in the production environment. Papers that take this approach are relatively few and include [13,16,42,58].…”

“…In order to address the limitations that come from fixed department locations, several authors have recently proposed that functional departments should be duplicated and strategically distributed throughout the plant floor [13,16,58]. Duplication would not necessarily mean acquiring additional capacity but could simply be achieved by disaggregating existing departments, which may consist of several identical machines, into smaller ones.…”

“…Existing layout design procedures, whether for functional or cellular layouts, have been, for the most part, based on a deterministic paradigm, where design parameters, such as product mix, product demands, and product routings, are assumed to be all known with certainty [29,54,56,72]. The design criterion used in selecting layouts is often a static measure of material handling efficiency (i.e., a total adjacency score or total material handling distance) which does not capture the need for flexibility and reconfigurability in a dynamic environment [9,10,13,43]. In fact, the relationship between layout flexibility and layout performance remains poorly understood and analytical models for its evaluation are still lacking.…”

“…There is an emerging consensus that existing layout configurations do not meet the needs of the multi-product enterprise [4,13,37,42,58,59,61,79,82] and that there is a need for a new generation of factory layouts that are more flexible, modular, and more easily reconfigurable. Flexibility, modularity, and reconfigurability could save factories the need to redesign their layouts each time their production requirements change.…”