Production scheduling of bar mill using the combination of particle swarm optimization and Nawaz enscore ham for minimizing makespan in steel company

Production scheduling is defined as the way of allocating resources or machines to process a set of tasks within a certain period. A flow shop production system requires scheduling to set up a job priority. This research takes place in a steel company located in Cilegon, Banten, which produces Bar Mill and Section Mill. There are two types of bar mill products, namely deformed bar mill and plain bar mill. These types of products are distinguished from their diameters. Among all products, the highest demand for bar mill Type is D.16, D.19, D.22, D.25 and D.32. However, during the period of time, the sequence of producing the Bar Mill is timely basis without considering the volume of the demand. This condition leads to longer completion time and makespan. Therefore, to solve the problem, we propose the application of production scheduling method by combining particle swarm optimization with Nawaz Enscore and Ham (NEH) algorithm as the initialization. The result shows that there is an improvement in makespan after applying the proposed method. Total makespan for existing condition is 721.87 h. The proposed method is capable to reduce the makespan into 695.76 h by applying particle swarm optimization method with random initialization. The scheduling using particle swarm optimization method with NEH initialization generates makespan of 678.04 h. Based on the results and analysis, the application of particle swarm optimization method with NEH initialization show a better performance compared to other scheduling methods.