Abstract—The Government Pharmaceutical Organization (GPO), a state enterprise under the Ministry of Public Health is one of the pharmaceutical manufacturers in Thailand. The GPO produces various different dosage forms of medical products such as solid, semi-solid, liquid and injection dosage form. A nowadays solid dosage form which is the main product type is confronted with backorder problem. Anti-Retroviral (ARV) drugs also face with this problem. The ARV production line can be divided into 4 stages, mixing, compression, coating and packing. Each process is designed as a job shop environment. The production of ARV drug is considered complex and must comply with regulations such as GMP/PICs in order to prevent contamination between drugs and quality of drugs. Thus, sequencing and assigning the task is tedious but crucial. This paper aims to develop a mathematical model for a job shop scheduling problem with sequence dependent setup times. The developed model utilizes a binary linear programming technique whose objective is to minimize a maximum completion time of all the jobs.