Utilities around the world have made a series of transitions from just serving customers, to serving customers reliably, to now serving customers in reliable, cost effective manner. This service transformation demonstrates not only an increased sophistication on the part of the utility but also emphasizes the increased value electric energy has to the customer. Customer changes are driven by many market and social elements and can take place quite rapidly. Utility changes are driven by the vision and wisdom of the top utility leaders and must strategically and thoughtfully be communicated to the utility as a whole if sustaining change is to take place. Both of these changes are normal in an evolving market.
The desire to increase the overall effectiveness of maintenance resources by optimizing the use of routine maintenance has resulted in many utilities turning to RCM (Reliability Centered Maintenance). In particular, RCM techniques have been employed because of its successful track record in other competitive industries and because of its technical, unbiased, practical and logical approach to maintenance. A Utility’s desire to emphasize the application of predictive maintenance techniques is fundamentally supported by RCM. The preventive actions directed by an RCM process are focused on preserving the fundamental functions of equipment and are based on the condition of equipment and predicting it’s remaining life, not just merely on a schedule.
RCM embodies both the basic objectives highlighted above. First, overall maintenance resource expenditures will be optimized after the routine maintenance program is optimized. Second, RCM emphasizes the use of predictive techniques. Sometimes these techniques are referred to as condition monitoring or diagnostics tasks.
The technical approach employed in the development of the optimal routine maintenance strategies requires the use of expert utility knowledge. This knowledge is found in abundance in the hearts and minds of the utility employee and is generally unleashed in the first RCM pilot project. In addition to active participation in pilot project activities, participants learn the basic steps of RCM result. The practical experience gained with a real life RCM application will also promote understanding and acceptance of both methods and results of the project. The pilot project makes use of key maintenance and operations personnel that would be responsible for future RCM studies, and narrowly focuses the use of other utility personnel where it is believed their expertise and time is best utilized.
Two of the highest priority substations will be reviewed using RCM methods. The technical approach and documentation of results will be such that future work can be based on the finished product of the first phase. Although the results cannot simply be copied, they can be effectively “migrated” to the remaining substation equipment, given sufficient similarities. If stations are sufficiently large, a subset of each station or analysis of only one station may be the prudent RCM approach.
The resultant programs will identify specific modes of failure for each equipment item and its relative criticality. Criticality (prioritization) will be assigned to each mode of failure. Only failure modes that fail important functions will be considered. The project will also identify dominant causes of critical failure modes so routine maintenance tasks can be specified.
The end result of RCM studies will be a listing of routine maintenance tasks that are the most technically correct and cost-effective to address the causes of critical modes of failure. In addition to these applicable and cost-effective routine tasks, other recommendations may be made. These recommendations include design modifications, design change outs, and changes in operation. Although these are less frequently recommended, in some cases they are necessary to ensure the cost-effectiveness of routine tasks. In other cases, they are used to eliminate the need for routine maintenance when it is found that routine maintenance tasks are not cost-effective in addressing the cause of equipment failure.
Where appropriate, consideration will be given to the use of online monitoring and other predictive maintenance tasks. Condition monitoring can be performed online or offline, continuous or periodic. When making determinations in the use of online monitoring equipment, the cost of acquiring and installing online monitoring will be to be weighed against the benefits that such monitoring provides. Typically, online monitoring is most desirable in cases where progression to failure is rapid, and where the cost of equipment replacement and repair is extreme. In addition, online monitoring is also useful in cases where equipment is located in remote areas, and periodic onsite monitoring is costly.