Maintenance is required to keep the facilities and equipment in good working condition so that it can deliver better performance without causing any loss of time. A collective measures taken up by the industry in order to keep the equipment or machine in trouble free environment or in good environment is called maintenance engineering. In this Paper, we discuss on the Operation Research techniques which can play the vital role for reduce the Machine breakdown. Operation research techniques may help for proper Maintenance planning, Scheduling of preventive maintenance & Spare parts planning.