What is RCM and RBI

RCM is Reliability Centered Maintenance

It is a different way at studying and maintaining equipment, based on the following;

RCM is an on-going process which determines the mix of

Reactive, Preventive, and Proactive maintenance practices

To provide the required reliability at the minimum cost. It can use diagnostic tools and measurements to assess when a component is near failure and should be replaced.

The basic thrust is to eliminate more costly unscheduled maintenance and minimize preventive maintenance.

An on-going process which determines the mix of reactive, preventive, and proactive maintenance practices to provide the required reliability at the minimum cost. It can use diagnostic tools and measurements to assess when a component is near failure and should be replaced. The basic thrust is to eliminate more costly unscheduled maintenance and minimize preventive maintenance.

Methodology used to define a maintenance program while having reliability as an input to the decision making process. Originally developed by the aviation industry and known as MSG-3 (Maintenance Steering Group), Reliability Centered Maintenance or RCM has since been adopted by many different industries. www.relexsoftware.com/reliability/glossary.asp is a process to determine why and what PM is performed on equipment based on its role in maintaining system function. www.lincolntechnology.com/re/redefs.htm

A structured process, originally developed in the airline industry, but now commonly used in all industries to determine the equipment maintenance strategies required for any physical asset to ensure that it continues to fulfill its intended functions in its present operating context. A number of books have been written on the subject, but none better than Moubray's book, RCM II. www.maintenanceresources.com/ReferenceLibrary/MaintenanceManagement/KeyTerms.htm

RBI is Risk Based Inspection

It is a different way at looking at doing maintenance on equipment, based on the following;

It is now widely accepted that the traditional time-based approach (PM's) to planned plant inspection by a competent person has a number of shortcomings. In particular, the use of fixed intervals between inspections may be too conservative and lacks the freedom to benefit from good operating experience. The introduction of goal setting legislation has facilitated a move towards risk based strategies, which focus inspection resources on parts of the plant where they will have the greatest benefit.

Risk based inspection considers the probability of failure and its consequences. The technique is intended to get better value for money from inspection.

RBI is a technique, which is currently being adopted by some sectors of industry, particularly the refining and petrochemical sectors, to underpin and direct planned plant inspection. It is claimed to offer the prospect of cost savings resulting from better targeting of resources. RBI recognizes that

there is little point to spending good money, for example, on very frequent inspection of something that is very unlikely to fail, or if it did fail would have little financial or safety consequence. In line with the principles of ALARP (as low as reasonably practicable) the money saved may be better spent elsewhere. Savings can also arise from reduced direct inspection costs.

There can be additional safety benefits by use of the technique, since it focuses on critical plant and identifies priorities for inspection based on the risk of failure.

Whether the RBI technique achieves safety standards which are at least the equivalent of conventional techniques will depend amongst other factors on:

The accuracy of data used in support of risk assessment methods The arrangements for audit and review of RBI methods

The motivation for change from conventional inspection methods

The principle of RBI is likely to become more widely used in the future. Whilst any review of inspection is probably beneficial, and any initiative aimed at saving money may be expedient the costs of moving to RBI should not be underestimated.

RBI is a powerful tool - if carried out correctly. There is a longer term potential, with reduced downtime etc, for genuine cost savings. Without full support, the technique may not give the expected benefits and decisions on changes to maintenance methods may not be based on sound evidence. Most importantly, the real function of good inspection - to achieve the highest level of safety - must not be forgotten.