Cell formation using sequence information and neural networks

Abstract

Most neural network approaches to the cell formation problem have been based on Competitive Learning-based algorithms such as ART (Adaptive Resonance Theory), Fuzzy Min- Max or Self-Organizing Feature Maps. These approaches do not use information on the sequence of operations on part types. They only use as input the binary part-machine incidence matrix. There are other neural network approaches such as the Hopfield model and Harmony Theory that have also been used to form manufacturing cells but again without considering the sequence of operations. In this paper we propose a sequence-based neural network approach for cell formation. The objective function considered is the minimization of transportation costs (including both intracellular and intercellular movements). Soft constraints on the minimum and maximum on the number of machines per cell can be imposed. The problem is formulated mathematically and shown to be equivalent to a quadratic programming integer program that uses symmetric, sequence-based similarity coefficients between each pair of machines. To solve such a problem two energy-based neural network approaches (Hopfield model and Potts Mean Field Annealing) are proposed.