To study in order to acquire the effective resolution to reduce and control the machine breakdown of critical machine in the fish snack production line as a result of lacking of the appropriate and effective machine maintenance system. The study has been conveyed by adopting the preventive maintenance system to increase the effectiveness of the operation of the machine in the production line and to reduce and prevent the machine breakdown and to provide the safety awareness in the workplace. The study begins with the analysis on the existing maintenance system. The data in connection with the down time and cost of loss time caused by the sudden machine breakdown have been collected throughout the study. The find-out indicates that there are various problems in management structure within the engineering department and the existing machine maintenance system causing the cost of loss time in the production line. The analysis equipment and method being used is to compare the existing machine maintenance system with the preventive maintenance program based upon types of cause of machine damage and the appropriate maintenance system to prevent the re-occurrence of such damage. Furthermore, the management structure within the Engineering department has been improved prior to the implementation of the preventive maintenance program. From the study, the preventive maintenance system has been implemented and adopted in place of the existing maintenance program that provides repair and maintenance only after damage and machine breakdown has been occurred. First step of the process is to restructure the management line within the Engineering department to increase its management effectiveness. Also, the procedure manuals and work instructions have been implemented to comply with the ISO 9002 standards. After the implementation of the preventive maintenance program, it is found that the machine breakdown rate has been significantly decreased from 12 times per monthto 5 times per month and the cost of loss time has reduced for 73% and no serious accident has occurred within the 600 day period up to present.