Pumping stations are a critical component of the Metropolitan Council Environmental Services (MCES) collection system. Traditional operations and maintenance (O&M) practices were not providing the desired level of pumping availability and the problem was becoming worse as equipment aged and knowledgeable staff became eligible for retirement. O&M staff agreed that work could be done more effectively to improve collection system reliability, but everyone had a different idea of how improvements could be made. As part of its enterprise asset management strategy, MCES selected a Best Management Practice called Reliability Centered Maintenance (RCM) analysis to improve O&M results. An RCM study was performed on a critical lift station to evaluate existing operations and maintenance practices and determine if they could be improved to: 1. Increase the reliability of the lift station, especially during critical flow events, 2. Determine the right maintenance strategy to support day-to-day lift station operation, and 3. Determine the right amount of staff to sustain the lift station’s function. The RCM study was conducted in a facilitated, workshop environment to analyze the essential functions of the lift station, identify critical equipment and define the operating and maintenance tasks that could prevent critical failures. MCES used the 7-Step Classical RCM process, which provided a clear and straightforward path through the system analysis process. The result was a compelling recommendation with specific enhancements designed to immediately improve the current lift station maintenance strategy. Based on input from senior operators and maintainers and data from MCES’ Oracle WAM Computerized Maintenance Management System (CMMS), the study documented a practical maintenance strategy based on real-world experience that balanced resource demands with reliability, factoring in the station’s high level of design redundancy. At the end of the RCM study, the participants provided an evaluation of the process itself. The application of RCM was unanimously supported as a valuable tool by the group, with certain cautions about the best areas of applicability. Subsequently, Experience Centered Maintenance (ECM), a less intensive maintenance analysis methodology that compliments RCM, was used to evaluate and improve maintenance practices for less critical lift stations. The ECM study provided insight on the merit of existing preventive maintenance tasks and recommended several additional tasks that would improve reliability and reduce cost. The O&M procedures derived from RCM and ECM eliminate surprise failures and efficiently use staff resources. The procedures were developed by and for O&M staff and as a result have a great deal of ownership and buy-in that has benefited implementation. Management has found the results helpful in providing a basis for O&M budgets and determining staffing levels.
How Much Maintenance is Enough? RCM Delivers the Right Maintenance Strategy for a Critical Lift Station
Authors: Deborah Rose, Samuel Paske, Anthony M. Smith
2011 WEF Collection Systems Conference