European Journal of Operational Research 43 (1989) 119-135 119 North-Holland Invited Review Flexibility of manufacturing systems: Concepts and measurements Yash P. GUPTA Department of Management, University of Louisville, Louisville, K Y 40292, USA Sameer GOYAL Department of Actuarial and Management Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada Received July 1989 Abstract: The issue of flexibility is assuming increasing importance in manufacturing decision making. Flexibility is important to accommodate changes in the operating environment. Manufacturing systems that are flexible can utilize the flexibility as an adaptive response to unpredictable situations. Many researchers have defined various types of manufacturing flexibility and provided methods for measuring them. In this paper we have classified the literature based on the ways researchers have defined flexibility and the approaches used in measuring it. Keywords: Flexible manufacturing systems, manufacturing flexibility, classification 1. Introduction US manufacturing started to experience some environmental changes in the mid 1960s due to growing technological change, increasing federal regulations, and more importantly foreign compe- tition. The manufacturing companies started to exhibit serious problems with manufacturing per- formance as foreign competition gained even more momentum. Deeply embedded in the dogmas of giant plants, economies of scale, and docile work forces, these companies are now facing the reper- cussions of competition, shorter product life, and increasing fixed costs. Also, there has been an Received July 1989 increasing demand for product quality, reliability, innovation, technology, and quality of work life (Skinner, 1985; Hayes and Wheelwright, 1984). The conventional form of manufacturing has mainly relied on two kinds of equipment. The first --dedicated machinery such as transfer lines--is best suited for mass production of a single part. This process specialization permits low unit costs, but it also inhibits flexibility. The second--non- integrated general purpose machine tools--is best suited for very small batch production of many different parts. Costs per unit tend to be high, but the flexibility of the process can accommodate design changes, demand fluctuations, and shifts in product mix. Today, advanced manufacturing sys- tems such as flexible manufacturing systems (FMSs), computer aided design/manufacturing (CAD/CAM), and Just-in-Time (JIT), offer a third 0377-2217/89/$3.50 © 1989, Elsevier Science Publishers B.V. (North-Holland)