Proposed Production Scheduling Using Non-Delay Algorithm to Reduce Makespan (Case Study: PT. XYZ)

PT. Xyz is a manufacturing company that produces piano musical instruments. There are two types of pianos produced, namely Grand Piano and Upright Piano. Where each type has a variety of models. Due to the diversity of piano models and types, companies had to divide the work. There are sections of woodworking, assembly, and painting. Each part has a different production process. In the Cabinet Side section, the system flow in production belongs to the workshop category because many models and cabinets are manufactured using different machines. This causes the Cabinet side to experience problems, namely the difficulty of achieving daily targets. Ineffective resource allocation and scheduling are at the root of the problem. The current scheduling system is the FCFS system or items that arrive earlier will be processed earlier. In other conditions, the Cabinet Side Section schedules the most targeted cabinets that are planned to be produced to be prioritized in their work. Based on this, this study aims to reduce makespan by designing a production scheduling proposal using a non-delay algorithm method for several machines. The object under study is the B1 and B3 cabinet models because they have the most productive targets among other models. The data that has been processed produces a makespan from the company's actual schedule of 321.66 minutes with the order of completion J3-J8-J7-J5- J6-J2-J1-J4. Scheduling with a non-delay algorithm method produces a makespan of 277.31 minutes with the order of completion of work J8-J3-J5-J7-J6-J2-J4-J1. The proposed scheduling non-delay algorithm method is able to reduce makespan by 13.78% or 44.35 minutes. This proves that this method is good for companies to implement. This is supported by the resulting efficiency index value greater than 1 (E > 1) which is 1.16, meaning that the performance of the non-delay algorithm method is better than the actual completion of the company's processes. Keywords: production scheduling, job shop, non-delay algorithm, makespan