Predictive Maintenance
This is a condition-based maintenance strategy. This is where predictive technologies (i.e. - vibration monitoring, infrared thermography, ultrasonics, etc.) are utilized to determine condition of equipment, then decisions are made about necessary repairs. This is a much more economically feasible strategy as labor, materials and production schedules are used much more efficiently.
Precision Approach
This is a concept of the future, though not any revelation. The concept is that if we did our jobs with a mastery level of precision, then the only failures we would have, would be wear-out failures. Maintenance statistics support that approximately 10% or less of our industrial equipment ever reached wear-out stage. Therefore, about 90% of the mechanical failures we experience are "personnel avoidable events". This means the human being has intervened in some manner that prevented the wear-out stage from being attained.
Strategies to Control Failure Rates
Reliability Centered Maintenance (RCM)
In its traditional state, as written by John Mobrey, the goal of RCM is to determine the criticality of equipment in any process, and based on this information, design a customized Preventive/Predictive maintenance strategy for the organization. This is an effort to optimize use of our maintenance resources.
However, this is an extremely time consuming and expensive process when done according to the text. The end result is that we become sharpened responders, therefore still reactionary. Bottom-line results are typically incremental and not seen for years.
Root Cause Failure Analysis (RCFA)
RCFA is a strategy that is based on failures that have occurred in the past, whether chronic or sporadic. Their impact is determinable because labor, materials and lost production is now a sunk cost. RCFA focuses on eliminating the risk of recurrence of the failures by identifying the physical, human and latent (organizational) system roots that lead to the failure. Typically the worst drain on an organization's maintenance budget is not the one time occurrences, but the "cost of doing business" chronic failures that are accepted.
Generally 20% or less of the failure events in any organization cause 80% or greater of the losses experienced. When resources are dedicated to identifying these 20% of the events, an immediate bottom-line result can be realized if they are analyzed and corrective action taken. The accepted chronic failures stop occurring, therefore labor hours are not assigned to them, materials are not expended and production increased because there are no constant stops and starts of the process. This also increases quality of product and reduces risk of safety and environmental incidents because of the smoother running process.
Most costs associated with conducting a RCFA is in people's time and resources to verify findings. Recommendations are generally non-capital expenditures that correct people's decision-making skills and the information they receive. For example, oftentimes people need to be trained in their craft or a new technology they are using, or we must correct an obsolete maintenance procedure or simply provide the correct tools to do the job right the first time.
Synopsis
RCM coupled with RCFA covers all the bases in moving towards total Failure Avoidance. RCM may be necessary to gain control of an operation, however it is time consuming and expensive up front. RCM's returns are not realized quickly.
RCFA is real time. It deals with today's problems and eliminates them from being tomorrow's problems. Bottom-line results can be immediate if recommendations are acted on quickly. RCFA can be proactive when accepted chronic failures that comprise the maintenance budget are eliminated from recurring.
Written by Robert J. Latino, Reliability Center, Inc.
Robert J. Latino is Vice-president of Strategic Development and a Senior Consultant for Reliability Center, Inc. Mr. Latino is a practitioner of root cause failure analysis in the field with his clientele as well as an educator. Mr. Latino is an author of RCI's Root Cause Failure Analysis Methods course and co-author of Failure Analysis/Problem Solving Methods for Field Personnel. Mr. Latino has been published in numerous magazines on the topic of failure analysis as well as a frequent speaker on the topic at trade conferences. He can be contacted at 804-458-0645 or blatino@reliability.com
