The Power of Maintenance Data
Reliability maintenance keeps evolving. First, the idea was originated many years ago by Nowlan and Heap as a maintenance procedure for military ships and combat aircraft. It was later more precisely defined in the SAE standard JA1011 (“Evaluation Criteria for Reliability-Centered Maintenance processes”) and fine-tuned by the late John Moubray. Then came RCM-II. And now we have “Living RCM” as defined by OMDEC, the Optimal Maintenance Decisions Inc. of Stittsville, Ontario. (Contact: chris@omdec.com)
The concept isn't really all that new. OMDEC did a workshop on this in September 2008 in Toronto. But the specific software has since been enhanced. Murray Wiseman, vice-president of engineering at OMDEC, wrote a technical review of Living RCM, titled “Unleashing the power of maintenance data,” in which he says that information drives the maintenance process. He argues that enterprises devote significant resources to their maintenance information systems. Yet, those systems rarely deliver optimal, unambiguous, and verifiable decision support. Maintenance engineers seldom analyse their equipment health monitoring and work order databases so that they can improve predictive performance. In other words, the reliability-centred maintenance approach is often misunderstood and underused. Yet it is the most powerful tool available to manage sustainable equipment availability. It is an approach to improve machine reliability while, at the same time, it helps to control maintenance expenses. That's because RCM is a logical technical process to determine which maintenance task will best ensure optimal equipment performance in specified operating environments. The goal is to make each system as reliable as it was designed to be.
Wiseman also opines that benefits derived from a variety of maintenance initiatives undertaken over the years elude quantification in current management information systems. He thinks that is because those systems lack one indispensable element of control. And he proposes that this missing process is Living RCM, or LRCM for short.
So, what exactly is LRCM, how does it work, and what are its benefits?
Let's first look at the challenges that RCM faces. They are two-fold: first, initial RCM analysis is based on best judgment and recollection by a team of experts. But information at the disposal of the team is often incomplete. The RCM analysts will tend to select conservative tasks and frequencies. The analysis must, therefore, be revisited and refined continuously in the light of new information from maintenance events as they occur. Second, operating contexts, economics, and requirements evolve continuously. However, the typical RCM knowledge base, once delivered, remains static. Therefore, valuable information from the work order process remains largely untapped and unavailable to support reliability analysis and improvement.
Overcoming these reliability challenges through LRCM involves the following integration steps into mainstream maintenance:
Linking each significant work order to one or more knowledge records. In this way work orders become true instances of failure modes. Those failure modes are precisely defined in the RCM knowledge base.
Recording the event type (e.g. potential failure, functional failure, suspension) of each identified failure mode. Event types define life cycles, and life cycles are the “data points” that reliability analysis analyses.
Using LRCM software to track changes to the knowledge base and recognizing the knowledge contributors.
Using reliability analysis methods to improve prevention and prediction, in particular implementing (EXAKT) decision models for the automated detection of potential failures.
Using reliability analysis methods to assess predictive and preventive performance.
The major functions of LRCM are thus database integration, data preparation for reliability analysis, knowledge management and, finally, reliability analysis.
According to Wiseman, these steps yield the following benefits:
A continuously improving knowledge base enabled by LRCM.
The ability to perform quick and convenient reliability analyses, making reliability and cost improvement a natural process.
Fully displayed RCM knowledge record and operating context, leaving no doubt when linking a work order to the appropriate failure mode.
Motivated knowledge contributors through automatic recognition.
Flexible, convenient, universal access to RCM knowledge by location, or by equipment type.
Filtering and grouping of work order and condition-based maintenance (CBM) data.
Drilling down and drilling through to the work order and knowledge record.
Native analysis methods (Weibull, Pareto, Jack-knife etc).
Error-free events table generation for CBM optimization and remaining useful life estimation (RULE) models, using EXAKT software.
Workflow and information flow designed to encourage active participation in continuous process improvement.
RCM knowledge base responsive to evolving context, requirements, and new information about failure behavior as revealed through the routine work order process.
Integration with Maximo, SAP, Ellipse and other CMMS software.
Thus, reliability knowledge is captured at the opportune moment when attention, interest, and information are at their peak. Not a bad way of doing maintenance. We need strategies for obtaining greater reliability and we must remember that the primary focus of maintenance is – or should be – avoiding downtime and improving maintenance productivity and efficiency. LRCM could be just the ticket.
Steve Gahbauer is an engineer, a Toronto-based freelance writer, and the former engineering editor of “Plant.” Reach him at gahbauer@rogers.com