MAINTENANCE PLANNING AND SCHEDULING FOR A CEMENT GRINDING UNIT (A CASE STUDY)

Modern technologies are characterized by high level of automation deploying complex and sophisticated machines. The objective behind is to achieve higher productivity and profit in business. This has resulted in total dependency on machines. Therefore machines should remain in operation without any trouble. It is always desirable to achieve maximum calculated output from every equipment, machine and organization. In cement industry the grinding process is one of the most energy consuming processes. Approximately 65-75% of the total power consumption is used in grinding process, which is carried out in Ball Mills. GUJARAT AMBUJA CEMENT LTD. (ROOPNAGAR) is a grinding unit having four ball mills for cement grinding. As the cement manufacturing is the continuous process, it is necessary to properly maintain the ball mill for efficient production. Any small reduction in downtime of a cement ball mill can increase its production. Downtime or maintenance time can be reduced by analyzing the failure pattern of critical parts of cement ball mill. Most troublesome cement ball mill-2 has been selected for developing a new plan and schedule by using six step method. Last five year data has been collected and analyzed by using six step method and a new maintenance plan has been scheduled for cement ball mill–2. The study suggests that downtime of a cement ball mill can be reduced by 20% for one time maintenance work of all critical parts. Next five years maintenance plan has been proposed which reveals that there can be 7 % reduction in total maintenance time