Mathematical Modeling for a Flexible Manufacturing Scheduling Problem in an Intelligent Transportation System

This paper presents a new mathematical model for a production system through a scheduling problem considering a material handling system as an intelligent transportation system by automated guided vehicles (AGVs). The traditional systems cannot respond to the changes and customer's demands and for this reason, a flexible production system is used. Therefore, for this purpose, automated transportation systems are used for more flexibility in production. Thus, several AGVs are considered to perform various jobs among different machines and warehouses. In this production system, there are possibilities of failure and breakdown of AGVs and machines simultaneously. A modified rate is considered for determining the maintenance duration time as a percentage of the setup time when the maintenance time is dependent on the total setup time of machines and the total transfer jobs time of AGVs. Hence, we consider the probability of breakdown of AGVs and machines simultaneously and show the effect of these problems. The objective function is to minimize the maximum completion time (i.e., makespan or Cmax), the tardiness penalty, and the total transportation cost bearing in mind that the impact of new constraints with mathematical innovation on how failure and repair time are affected by the entire production scheduling. The proposed model belongs to mixed-integer linear programming (MILP). Finally, several small-sized problems are generated and solved by the CEPLEX solver of GAMS software to show the efficiency of the proposed model.