Lecture 6 - Maintenance Tactic Development

Question 1

What is RCM?

Answer 1

• RCM = Reliability Centered Maintenance
• It is one method for determining the maintenance tactic (strategy) for equipment
• Other methods commonly used include:
  – Adopting Manufacturers’ (OEM) Recommendations
  – Using the PM program from other, similar equipment
  – Reverse RCM or PM Optimisation
  – Based on gut feel and experience

Question 2

What are the aims of maintenance strategy/tactic developlent?

Answer 2

• Detect and correct incipient failures either before they occur or before they develop into major defects;
• Reduce the probability of failure;
• Detect hidden failures that have occurred;
• Increase the cost-effectiveness of the maintenance programme.
  REFER TO SLIDES FOR VISUALS AND IMPORTANT GRAPHS

Question 3

What are the seven key questions of RCM?

Answer 3

Refer to slides

Question 4

What is the difference between RCM and PMO (reverse RCM)?

Answer 4

• RCM generates a list of failure modes from a rigorous assessment of all functions, consideration of all functional failures and then an assessment of each of the failure modes that relate to each functional failure. The primary objective of RCM is to preserve asset function.
• PMO generates a list of failure modes from the current maintenance program, an assessment of known failures and by scrutiny of technical documentation.

Question 5

What are some criticisms to be aware of for RCM

Answer 5

• Time consuming and resource hungry. If senior management loses interest the process can stall as people are deployed elsewhere before benefits can be realised.
• Difficult to measure ‘value’.
• Full RCM analysis results in a significant number of failure modes assigned a tactic of ‘no scheduled’ maintenance because a PM is not feasible or because it is feasible but not cost effective.
• The use of RCM templates can result in errors when considering primary and backup units as the failure modes of the two can be different.
• People applying RCM are so focussed on developing PM activities that they lose sight of proactive solutions that can eliminate the functional failure

Question 6

What are some criticisms of PMOs

Answer 6

• Unless special steps are taken to identify failure modes that have not happened but are likely to happen, you may have unmitigated hazards in the plant.
• PMO may not identify ‘hidden’ failures and hence is weak on specifying appropriate maintenance for protective devices.
• PMO does not list a complete set of failure modes.
• PMO assumes that all the failure modes associated with equipment are covered by the existing maintenance program.
• PMO often focuses maintenance workload reduction rather than plant performance improvement.

Question 7

What is the issues with both RCM and PMO approaches?

Answer 7

• Neither process provides adequate protection against the
  consequences of equipment failure where two failures occur simultaneously.
• Few operations have a live-program where the FMEA analysis
  (regardless of the method) used is updated following new failures or improved understanding and experience. Often the analysis is put on a shelf and forgotten about.
• Problems in the asset register and with data in the CMMS system can stall both processes.
• Inexperienced analysts may propose a condition monitoring task without considering that a failure must give a warning and that warning must provide sufficient time for action (P-F interval).
• Often the ‘forward thinking about what the problems could be’ does not agree with what problems are actually experienced.