Job shop scheduling is an Np-Hard combinatory in the field of scheduling problem. Due to this reason, Dejena Aviation Industry (DAVI) has faced a problem to determine the optimum sequences of jobs on machines that can optimize the makespan. The purpose of this study is therefore, to minimize the makespan of the job shop production system of DAVI production system using shifting bottleneck algorithm. Secondary data was collected from the production log book five machines were considered during the production of five jobs. The findings of the shifting bottleneck algorithms showed that an 8.33% reduction in the total makespan of the company job shop production system. Moreover; machine one (41%) and three (36%) are found to be least utilized machines whereas machine three (64%) and five (59%) are relatively the busiest machines.