An Application of Production Scheduling Problems with Sequence-Dependent Setup Time in a Glass Bottle Forming Process

Abstract

In this research, a parallel identical machine scheduling problem with sequence-dependent setup time is applied in a glass container manufacturing plant. The production scheduling program is developed to provide the optimal production schedule for 82 products with 9 identical individual section machines in a forming process with a minimum makespan objective. The machine setup time depends on the sequence of products produced. By using Visual Basic for Applications in Excel, a mathematical model is developed from input data and imported data from a database. The problem is solved by branch and cut algorithm using OpenSolver and Premium Solver. The answers from the program are translated and illustrated in terms of tables and Gantt charts that report the production sequence and total makespan. The results show that OpenSolver has the capability to solve the problem of 20 products and 4 machines, which is the maximum problem size of the case study company when using a present production plan within 3.65 hours. A new production plan or schedule for 82 products with 9 machines using Premium Solver is also proposed. The new production schedules give 4.79% lower makespan within 74.25 minutes.