USULAN PENJADWALAN JOB SHOP PADA PT X MENGGUNAKAN ALGORITMA PRIORITY DISPATCHING RULES DENGAN MENGAKOMODASI PENJADWALAN ULANG

• Main Author: Patricia Xu, Monica
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84249
• Institution: Institut Teknologi Bandung

PT X is a Japanese manufacturing company with a job shop production system that produces custom-made machine tools for the automotive industry. A problem symptom within PT X’s production system is the lateness of the actual production process exceeding the scheduled due date, which is experienced by approximately 38% of the historical production operation sequence, indicating the inefficiency of the production scheduling mechanism. The identified root cause based on the symptoms is the lack of relevancy of the existing production scheduling method to the production characteristics of PT X, namely the structural dependence between components, routing sequence, and the need for rescheduling. Several alternatives were considered for the algorithm used in the study, including the shifting bottleneck heuristic, priority dispatching rules, lot streaming, tabu search, and Nawaz, Enscore, Ham (NEH). The criteria applied to evaluate the alternatives encompass the scheduling type, type of algorithm, scheduling basis, and the ability to accommodate the case of rescheduling. Based on the criteria evaluation, the selected algorithm is based on priority dispatching rules, implementing two types of rules, namely the operation synchronization date and earliest due date (OSD;EDD), and the total work remaining and earliest due date (TWKR;EDD), to create a proposed production schedule in minimizing makespan as one of the crucial factors in decreasing production lateness. The data processing stage uses the historical production data of five orders, which runs through a full job and a rescheduling scenario. In the full job scenario, the proposed schedules based on the (OSD;EDD) and (TWKR;EDD) rules yielded 8671,7 hours and 8950,7 hours of makespan, generating improvements of 16,13% and 14,32% compared to the existing rule. For the rescheduling scenario, with the makespan of 8766,8 hours for (OSD;EDD) and 8931,3 hours for (TWKR;EDD), improvements of 27,92% and 26,57% in comparison to the existing rule were achieved. The (OSD;EDD) rule outperforms the (TWKR;EDD) rule, as the generated makespans are more efficient by 2,16% and 1,88% for each scenario.