Irohara Takashi

This paper presents a technique to solve the facility layout problem with rectangular departments of unequal areas. This problem can be formulated as a combinatorial optimization problem to minimize the total cost owing to material flow between departments. It is, however, computationally timeconsuming to find optimal solutions for large problems, because they are highly combinatorial in nature. Furthermore, these problems exhibit many local minim. These properties make them suitable candidates for the application of simulated annealing, which is a stochastic optimization procedure. A suboptimal method is then developed, which is a new improvement-type technique based on simulated annealing. In this technique, a new algorithm for updating placement of departments is proposed. This algorithm enables the application of simulated annealing to solve the problems considered here. This technique also offers increased flexibility to the optimization process, making the solution much less dependent upon the initial layout. Numerical results are given to demonstrate the effectiveness of the presented technique.

A Space Filling Curve (SFC) has been proposed, which allows for exchange among departments and offers increased flexibility to the optimization process, as a facility layout technique which can treat any departments of unequal area. However little attention has been paid to the department shape in spite of the fact that SFC determines the department shape. The Hilbert Curve (HC) is used as the SFC, but it gives poor estimation of department shape and is not applicable for use in some rectangular buildings. A new SFC is thus developed, which offers better estimation of department shape than SFC based on HC, and applicability for any rectangular building. Numerical results are given to demonstrate the effectiveness of the presented SFC.