To achieve better return on investment for any equipment, important components of costs along with equipment availability needs to be analyzed and corrective measures needs to be prepared.
For example, a plant may measure types of work (preventive, predictive, failure and modifications), labor and materials to identify important gaps in their maintenace capability. Let us assume that such analysis will provide information that 10% of the work is predictive, 40% is preventive, 30% is unexpected failure and approximately 20% of the PM is short closed each month. Although at high level this may look OK, but there could be huge overlap between preventive and predictive maintenance. Such unintended overlap increases costs and it occurs because of various activities like Preventive Maintenance and Predictive Maintenance are not planned in a unified system.
Most plants can build their PM programs over long period of time. Creation of PMs are done because they are hopped to reduce failure. Over time, these Preventive maintenance plans will grow to include inspections. Plants may observe some high visibility incidence that may require additional PM. The frequency will be set and the PM applied to every piece of equipment that is similar to the one that failed. It is natural that if machine failed, the boss is unhappy, and PM makes the boss less unhappy. Over time, the number of PMs Increases to the point that many aren’t being completed; even with an extensive PM program, there are still failures that can’t be eliminated.
With PM program getting stabilized with addtional failures, plant would begin additionally a PdM program by monitoring a few pieces of highly critical equipment with vibration analysis (where there usually is some success). In most cases these New PdM program also brings in additional benefits and leads to increase that success, the program would grow. If the organization has a lot of support corporately for implementation of PdM, they would typically apply the technology to 50% of their known assets and use all available technologies. To determine how many assets to monitor, the plant should determine how many technologists it can support and then buy the equipment needed to perform the work.
Conclusion: A well planned maintenance strategy needs mix of Preventive and Predictive methodology. Planning these strategy should be clearly documented along with what benefits it would bring in. Maintenance strategies are compiled and corresponding benefits are noted, it can be used along with current performance to identify possible future improvements in the area derive higher utilization of assets..
