Reliability-Centred Maintenance and Dynamic Maintenance Safety — a Winning Team
November 1, 2005 By Pulp & Paper Canada
Murray Wiseman has innovated in the maintenance field for more than 20 years. He is the founder and VP of Technology at Optimal Maintenance Decisions (OMDEC), the commercial distributor of EXAKT and t…
Murray Wiseman has innovated in the maintenance field for more than 20 years. He is the founder and VP of Technology at Optimal Maintenance Decisions (OMDEC), the commercial distributor of EXAKT and the EXAKT Work Order Processor (EWOP). Since he is an internationally known figure in this field, John Little interviewed him recently for Pulp & Paper Canada in order to share his experience and knowledge with our readers.
PPC: Murray, I want a better feel for the ties between a Computerized Maintenance Management System (CMMS), Reliability Centred Maintenance (RCM) and plant/process maintenance and related safety. s this a team-based exercise using vendors, design engineers, process engineers, IT (DCS) experts, process control specialists, safety specialists, users, operators, maintenance supervisors-managers-technicians, etc?
A: Yes, it’s a team activity. The specialists you mention are called in as required. The core team includes experienced maintenance and operating persons and first line supervisors and a trained RCM facilitator who is selected from the organization — not a consultant. The facilitator, as his main responsibility, makes sure that each RCM analysis benefits from all available knowledge – especially that which is locked in the memories of experienced personnel. Safety and environmental considerations come into play throughout the entire process. In the functional analysis, the team thoroughly exposes the hidden functions of protective devices as well as the structural integrity, containment, and control functions. The effects analysis describes the hypothetical scenario of events that may be touched off by, and lead up to, each failure cause. In the consequence analysis, hidden, safety, and environmental consequences are considered before operational and non-operational consequences. In the task analysis, safety procedures are explicitly stipulated — although their development is outside the scope of RCM.
PPC: Regarding CMMS software, the feedback I get from most maintenance experts/consultants is that each potential application must be assessed individually to determine what or which commercial CMMS software package best fits the client’s needs. What are your thoughts on this?
A: To a minor extent, yes. But management consultants have not yet seized a very important required function of a CMMS — to capture and return knowledge for the benefit of improving reliability, safety, and environmental integrity at lowest cost.
PPC: Doesn’t RCM, as developed by Nowlan and Heap and, later, John Moubray propose that all possible failure modes be analyzed, regardless of their relative severity?
A: This critique is often made, but it could not be farther from the truth. Neither N & H nor Moubray ever made this statement. Far from analyzing “all” failure modes, Moubray uses the expression “all reasonably likely” failure modes. He goes on to elaborate a process for determining those that are “reasonably likely” given the asset’s operating context.
PPC: Why not develop safe work procedures simultaneously with the failure mode and consequence analysis activities in order to reduce time lags, duplication of effort and key information transfer errors/loss to the operators, maintenance technicians and supervisors, process, safety and other specialists who, I presume, are developing these safe work procedures?
A: The RCM process tends to follow the sequence: 1) functional analysis; 2) failure analysis; 3) cause analysis; 4) effects analysis; 5) consequence analysis, and 6) task specification. Please note that all safety issues associated with functional failure of the asset, including those caused by human error, are thoroughly analyzed in the Failure Mode and Effects Analysis (FMEA) and consequence portions of the RCM analysis. It is only during task specification, however, that safety procedures associated with maintenance tasks are invoked. So the general answer to your question is that it is simply more expedient to get one job done — i.e., RCM where tasks, safety procedures and design changes are specified. And then, get on with other necessary follow-on jobs.
PPC: My Dynamic Maintenance Safety and Risk Assessment(DMS/RA) approach is based on the premise that line/maintenance employees cannot remember everything, that they learned ages ago in orientation and training. The purpose of ‘Time-of-Task’ based Hazard Analysis by the maintenance technician(s) is to identify only those hazards that are relevant to each step in the task about to be performed. It ascertains that no residual, new and/or ‘surprise hazards’ go undetected and unmanaged at the time a task is performed and that the procedures to follow in performing the task are current, relevant, safe and efficient (a last minute check before “Takeoff”!). Should not this process be performed within the RCM team meetings?
A: RCM defines what has to be done to preserve physical asset function. Physical assets have, among others, protective, control, containment, and structural integrity functions that need to be maintained. RCM discovers what those functions are, how they can fail, what happens when they fail, and how it matters. RCM then guides the selection of the appropriate task, design change, or procedural change to manage the consequences of the failure. With the growth of mechanization and automation, most safety, environment, product quality, and asset reliability issues are associated with the failure of some function of some electro-mechanical physical asset. Therefore, properly analyzing and maintaining function in the asset’s current operating context goes a long way to preserving life and the environment. RCM, however, does not preclude Dynamic Maintenance Safety and Risk Assessment, but complements and assists it, by having demystified the complex functional requirements of the asset into highly readable form. Both processes will gain by the successful application of the other.
John Little, B.Eng/CRM, is a consultant, dynamic maintenance safety and risk assessment(DMS/RA). He can be reached at email@example.com
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