Batch manufacturing is a dominant manufacturing activity in many industries due to the demand for product customization. The high level of product variety and small manufacturing lot sizes are the major | Luong L. H. S. et al Genetic Algorithms in Manufacturing System Design Computational Intelligence in Manufacturing Handbook Edited by Jun Wang et al Boca Raton CRC Press LLC 2001 6 Genetic Algorithms in Manufacturing System Design L. H. S. Luong University of South Australia M. Kazerooni Toosi University of Technology K. Abhary University of South Australia Introduction The Design of Cellular Manufacturing Systems The Concepts of Similarity Coefficients A Genetic Algorithm for Finding the Optimum Process Routings for Parts A Genetic Algorithm to Cluster Machines into Machine Groups A Genetic Algorithm to Cluster Parts into Part Families Layout Design A Genetic Algorithm for Layout Optimization A Case Study Conclusion Introduction Batch manufacturing is a dominant manufacturing activity in many industries due to the demand for product customization. The high level of product variety and small manufacturing lot sizes are the major problems in batch manufacturing systems. The improvement in productivity is therefore essential for industries involved in batch manufacturing. Group technology is a manufacturing philosophy for improving productivity in batch production systems and tries to retain the flexibility of job shop production. The basic idea of group technology GT is to divide a manufacturing system including parts machines and information into some groups or subsystems. Introduction of group technology into manufacturing has many advantages including a reduction in flow time work-in-process and set-up time. One of the most important applications of group technology is cellular manufacturing system. A cellular manufacturing system is a manufacturing system that is divided into independent groups of machine cells and part families so that each family of parts can be produced within a group of machines. This allows batch production to gain economic advantages of mass production while retaining the flexibility of job shop