Configuration design in scalable reconfigurable manufacturing systems (RMS); a case of single-product flow line (SPFL)

Abstract

The dynamic nature of today’s manufacturing industry, which is caused by the intense global competition and constant technological advancements, requires systems that are highly adaptive and responsive to demand fluctuations. Reconfigurable manufacturing systems (RMS) enable such responsiveness through their main characteristics. This paper addresses the problem of RMS configuration design, where the demand of a single product varies throughout its production life cycle, and the system configuration must change accordingly to satisfy the required demand with minimum cost. A two-phased method is developed to handle the primary system configuration design and the necessary system reconfigurations according to demand rate changes. This method takes advantage of Reconfigurable Machine Tools in RMS. In fact, by adding/removing modules to/from a specific modular reconfigurable machine, its production capability could be increased, with lower cost. A novel mixed integer linear programming formulation is presented in the second phase of the method to optimise the process of selecting the best possible transformation for the existing machine configurations. Two different cases are designed and solved by implementing the established method. The results of these cases in terms of capital cost, capacity expansion cost, unused capacity and number of transformations, are compared with two hypothetical scenarios. Analyses of the obtained results indicate the efficiency of the proposed approach and offer a promising outlook for further research.

Keywords:

• reconfigurable manufacturing systems
• reconfigurable machine tools
• optimisation
• system transformation
• modularity
• basic and auxiliary modules

Acknowledgements

The contributions from the head of industrial engineering department of Sharif University of Technology in considerable support of this research are greatly acknowledged.

Notes

1. This number is calculated by multiplying the number of outgoing edges of each selected RMT configuration + 1 (RMT configurations might remain unchanged). As for the example in this paper we have, 4() × 4() × 4() × 4 () × 3() × 2() × 1() × 1() = 536.