An integrated model of cell formation and scheduling problem in a cellular manufacturing system considering automated guided vehicles' movements

Abstract

In this paper, an integrated mathematical model for cellular manufacturing system (CMS) incorporating cell formation problem (CFP) and intra-cell scheduling is considered. It is assumed that in order to make the flexibility in handling system, automated guided vehicles (AGVs) are responsible for transferring the exceptional parts from one cell to another cell. Employing the AGVs in CMS can be challenging from mathematical model's point of view. In other words, despite the common constraints in CFP and intra-cell scheduling, several constraints such as AGVs' movement, preventing the AGVs' collision as well as parts' pickup/delivery by AGVs must be taken to account. There is no comprehensive model including the role of AGVs in a CMS. Hence, we endeavour to formulate CFP, scheduling and role of AGVs at the same time. The objective function is to minimise the sum of the maximum completion time (makespan) and inter-cellular movements of parts. The proposed nonlinear model is transformed to a linear form in order to solve it for optimality. Eventually, two small-size computational experiments are generated and ran on the GAMS.9 commercial software to show the efficiency and accuracy of the proposed model.