P L A N T M A I N T E N A N C E S T R A T E G Y

P L A N T M A I N T E N A N C E S T R A T E G Y
KEY FOR ENHANCING PROFITABILITY

Proper maintenance of plant equipment can significantly reduce the overall operating cost, while boosting the productivity of the plant. Although many management personnel often view plant maintenance as an expense, a more positive approach in looking at it is to view maintenance works as a profit center. The key to this approach lies in a new perspective of proactive maintenance approach.
Reviewing the most likely ways that equipment will fail has been a major concern in reliability-centered maintenance (RCM) to ensure that proactive, predictive and preventive maintenance activities during turnaround could be planned and carried out. So often that maintenance department will adopt a more cautious approach of playing safe and relying on the conventional or usual method of equipment maintenance rather than trying a proven method which has been tested to be efficient just to avoid any complicated matter arising from the method.
Hence another perspective of looking at maintenance function is not only to maintain but also to enhance the process or the plant operation system as a result of turnaround planning. Thus rather than restoring or trying to restore the equipment to its original performance, planning a turnaround could better still aimed at enhancing the process and performance of a plant, equipment or any system.
This paper will discuss on another option of looking at the maintenance function and as how to maximize the potential benefit of a maintenance activity. The idea might be very different from the conventional philosophy of maintenance but this might be something that well worth a thought for a new perspective in a new millennium.




Introduction
The definition of maintenance often stated maintenance as an activity carried out for any equipment to ensure its reliability to perform its functions. Maintenance to most people is any activity carried out on an asset in order to ensure that the asset continues to perform its intended functions, or to repair any equipment that has failed, or to keep the equipment running, or to restore to its favorable operating condition. Over the years, many new strategies has been implemented as a maintenance strategies which is intended to overcome the problems which is related to equipment breakdown. Some of the common maintenance strategies are as follows:-

1.BreakdownMaintenance
This is one of the earliest maintenance program being implemented in the industry. The approach to maintenance is totally reactive and only act when the equipment needs to be fixed. This strategy has no routine maintenance task and also described as no scheduled maintenance strategy. To rectify the problem, corrective maintenance is performed onto the equipment. Thus, this activity may consist of repairing, restoration or replacement of components. The strategy is to apply the corrective maintenance activity only, which is required to correct a failure that has occurred or is in the process of occurring.

2.PreventiveMaintenance
This is a time-based maintenance strategy where on a predetermined periodic basis, equipment is taken off-line, opened up and inspected. Based on visual inspection, repairs are made and the equipment is then put back on-line. Thus under this equipment maintenance strategy, replacing, overhauling or remanufacturing an items is done at a fixed intervals regardless of its condition at the time. Although this is a well-intended strategy, the process can be very expensive as typically 95% of the time everything was alright. Nevertheless, some preventive maintenance is necessary as some regulation such as DOSH regulation require that annual/bi-annual boiler inspection to be conducted.


3.PredictiveMaintenance
Predictive maintenance is a more condition-based approach to maintenance. The approach is based on measuring of the equipment condition in order to assess whether an equipment will fail during some future period, and then taking action to avoid the consequences of that failures. This is where predictive technologies (i.e. vibration analysis, infrared thermographs, ultrasonic detection, etc.) are utilized to determine the condition of an equipment, and to decide on any necessary repairs. Apart from the predictive technologies, statistical process control techniques, equipment performance monitoring or human senses are also adapted to monitor the equipment condition. This approach is more economically feasible strategy as labors, materials and production schedules are used much more efficiently.

4.ProactiveMaintenance
Unlike the three type of maintenance strategies which has been discussed earlier, proactive maintenance can be considered as an another new approach to maintenance strategy. Dissimilar to preventive maintenance that based on time intervals or predictive maintenance that based on condition monitoring, proactive maintenance concentrate on the monitoring and correction of root causes to equipment failures. The proactive maintenance strategy is also designed to extend the useful age of the equipment to reach the wear-out stage by adaptation a high mastery level of operating precision.