cellular manufacturing systems
... 1 Cellular Manufacturing Manufacturing industries are under intense pressure from the increasingly-competitive global marketplace. ... Manufacturing systems must be able to output products with low production costs and high quality as quickly as possible in order to deliver the products to customers on time. In addition, the systems should be able to adjust or respond quickly to changes in product design and product demand without major investment. Traditional manufacturing systems, such as job shops and ow lines, are not capable of satisfying such requirements. Job shops are the most common manufacturing system in the United States [13]. ... Machines are functionally grouped according to the general type of manufacturing process: lathes in one department, drill presses in another, and so forth. ... 1: Job Shop Manufacturing (Black [13]) processing more economical, parts are moved in batches. ... As indicated above, job shops and ow lines cannot meet todays production requirements where manufacturing systems are often required to be recon gured to respond to changes in product design and demand. As a result, cellular manufacturing (CM), an application of group technology (GT), has emerged as a promising alternative manufacturing system. Within the manufacturing context, GT is de ned as a manufacturing philosophy identifying similar parts and grouping them together into families to take advantage of their similarities Anan Mungwattana Chapter 1. ... 2: Flow Line Manufacturing in design and manufacturing [76]. CM involves the formation of part families based upon their similar processing requirements and the grouping of machines into manufacturing cells to produce the formed part families. ... A manufacturing cell consists of several functionally dissimilar machines which are placed in close proximity to one another and dedicated to the manufacture of a part family. The tenet of CM is to break up a complex manufacturing facility into several groups of machines (cells), each being dedicated to the processing of a part family. ... 1 is converted into a cellular manufacturing system (CMS) as shown in Figure 1. ... Introduction 4 M L L L L M D L L A Cell 1 Receiving and shipping L L M M L L M M D G G A D G A Cell 3 Cell 2 D G A Leftover process Floor spac available for manufacturing Figure 1.3: Cellular Manufacturing (Black [13]) CM is a hybrid system linking the advantages of both job shops ( exibility in producing a wide variety of products) and ow lines (ecient ow and high production rate). ... In conclusion, CM is a manufacturing system that can produce medium-volume/medium- variety part types more economically than other types of manufacturing systems [12]. ... The survey byWemmerlov and Johnson [97] arms that the greatest reported bene ts from CM appear along the dimension of time (manufacturing lead time and customer response time). Thus, CM represents a logical choice for rms whose strategy is time-based competitive manufacturing [87]. ... During the ve-year period ending in 1989, the estimated number of manufacturing cells operating in the U. ... 2 Bene ts of Cellular Manufacturing The advantages derived from cellular manufacturing in comparison with traditional man- ufacturing systems in terms of system performance have been discussed in [4], [15], [23], [27], [39], [40], [41], [51], [82], [96] and [97]. ... A manufacturing cell is designed to handle parts having similar shapes and relatively similar sizes. ... Instead of make-to-stock systems with parts either being run at long, xed intervals or random intervals, the parts can be produced either just-in-time (JIT) in small lots or at xed, short intervals. ... In CM, the manufacturing facility is broken down into manufacturing cells and each part travels with a single cell, resulting in easier scheduling and control. ... Collet and Spicer [23], in a case analysis of a small manufacturing company, found that cellular manufacturing systems resulted in a number of performance improvements when compared to job shops. ... These criteria included WIP, lead time, late orders, scrap, labor cost and manufacturing space. ... CM is considered as a prerequisite for just-in-time (JIT) manufacturing [82]. JIT requires manufacturing systems to have little or zero setup time, small lot sizes, and low inventory. ... Black [13] also emphasized that forming manufacturing cells is the rst critical step to achieve JIT manufacturing. ... 3 Design of Cellular Manufacturing Systems As described above, the bene ts resulting from CM can be substantial. ... Design of cellular manufacturing systems (CMSs) is a complex, multi-criteria and multi-step process. ... The design of CMSs has been called cell formation (CF), part family/machine cell (PF/MC) formation, and manufacturing cell design. ... Machines are grouped into manufacturing cells. ... Part families and manufacturing cells can be formed simultaneously, along with the assignment of part families to the cells. After the design steps have been completed, a manufacturing cell con guration (or cell con guration, for short) is obtained. It is referred to as a cellular manufacturing system (CMS) which consists of a set of manufacturing cells; each cell is constituted of a group of machines and is dedicated to produce a part family. ... 2: Reported Bene ts from Cellular Manufacturing in [96] Number of Average % Minimum % Maximum % Types of Bene t Responses Improvement Improvement Improvement 1. ... 0 Balllkur and Steudel [8] suggested three solution strategies based on the procedure used to form part families and manufacturing cells. ... Manufacturing cells are created rst based on similarity in part routings, then the parts are allocated to the cells. ... Part families and manufacturing cells are formed simultaneously. ... Manufacturing cells are formed with the objective of minimizing intercell moves. ... Further, any cell con guration should satisfy operational goals (constraints) such as desired machine utilization, production volume, number of manufacturing cells, cell sizes, etc. ... PCA-based systems are traditionally design-oriented or shape-based, therefore, they are ideal for component variety reduction. Some PCA-based systems, for example Opitz [61], incor- porate production-based codes as supplemental codes, which can be used for production planning. ... These models aim at obtaining disconnected subgraphs from a machine-machine or machine-part graph to identify manufacturing cells and allocate parts to cells. ... AI-based approaches, such as expert systems [9], [22] and neural networks [82], have been employed for designing CMSs because of their attractiveness in terms of com- putational time and ability to capture and employ design knowledge. ... Second is the lack of accounting for the presence of routing exibility in cellular systems, which often exists due to the availability of multi-function machines.