Authors: Najat Almasarwah, Gürsel Süer   Publication date: 2019/1/1   Journal: Procedia Manufacturing  

Abstract :

This paper explores the flowshop cell design in the cellular manufacturing system to minimize the number of machines, considering shifting the bottleneck machine and the annual demand. In a flowshop cell, products are processed through a series of production stages. Based on the number of machines per stage, the cell can be classified as either a production line (flowshop) or flexible flowshop. Two steps are followed in this study to design flexible flowshop cell. First, the un-capacitated mathematical model distributes the products into families and their corresponding machines into cells (product family formulation). Second, two non-linear mathematical models are proposed to design flexible flowshop. The first non-linear mathematical model is developed to build a flexible flowshop cell based on production rates. In this context, the number of machines in the system is determined, considering the machine duplication possibilities per stage for all products simultaneously, based on minimizing the total mean capacity required. The minimum number of machines per system is determined using a second non-linear mathematical model, with the objective to minimize the number of machines in the cell. In the two proposed nonlinear mathematical models, there is a limitation for the number of machine types. The results show that, as machine duplication is allowed, the number of machines per cell increases. Therefore, flexible flowshop design contributes to minimize the total number of machines in the system. In this way, the number of cells is reduced while production rates increase, and the total number of machines and total mean capacity required decrease.