Hybrid Make-to-Stock and Make-to-Order (MTS-MTO)Scheduling Model in Multi-Product Production System

Abstract

In production process, scheduling isan important role in meeting the orders and reducing the cost. This process becomes more complicated when the factory produces various products. Scheduling model in the production process can be divided into two groups: make-to-stock (MTS) and make-to-order (MTO). General constraint in the MTSmodel is limited production capacity and inventory cost. This work aims to propose hybrid MTS-MTO model that can improve lead time and maintain low inventory. In this work, we propose three hybrid MTS-MTO scheduling models for the multi-product production system. In these models, we modify several scheduling algorithms that are used in computer system, such as shortest remaining time(SRT), shortest processing time(SPT), and Round Robin(RR). These models are hybrid (s, S)-first-come-first served (FCFS)model, hybrid modified (s, Q)-SPT model, and modified (s, Q)-SRT model. This model then is implemented into production simulation. In this simulation process, we compare the proposed models with the existing item-by-item based (s, S)model. Based on the simulation result, these proposed models perform better than the basic MTS model. The hybrid (s, Q)-modified SPTmodel performs as the best model in creating high completion ratio, low lead time, and low inventory ratio. In certain condition, our proposed model performs 344 percent in completion ratio, 19.8 percent in lead time, and 3 percent in inventory ratio compared with the existing model.