Parallel Machine Scheduling with Shortest Processing Time (SPT) and Longest Processing Time (LPT) TO Minimize MAKESPAN at PT.ABC

Abstract

ABC is a manufacturing company in the Garment sector. The problem faced by the company is to determine the production strategy to be able to fulfill orders from consumers. The production process that is the object of research is the production process on a washing machine. The washing process has two identical machines installed in parallel that will do 10 jobs. Scheduling by the company currently uses the First Come First Served method with a makespan of 2255.7 hours. The research provides an alternative method for scheduling with the Shortest Processing Time and Longest Processing Time methods. The scheduling process using the SPT method produces a makespan of 2070.06 hours, while scheduling using the LPT method produces a makespan of 2039.34 hours. The proposed method in this research results that the LPT method produces a better makespan than other methods. The makespan efficiency of this research shows a saving of 9.59%, which is 216.36 hours.