Page 24 - RCM - A practical Guide_V1

RCM - A Practical Guide

OPERATING CONTEXT
To gain greater understanding, visibility and to assist in deriving the functions of each system, it is
beneficial to define the ‘Operating Context’ for the system/item under scrutiny.
In addition to a brief overall description the operating context for a particular equipment typically
includes the following:
• The physical environment in which the equipment is to operate
• The specific performance capabilities of the equipment
• Any variations in equipment type which would affect its capability
• The primary and any secondary roles that the equipment is required to do
• The micro and macro environmental conditions under which equipment is operated
• Any design or operator compensating provisions that will mitigate the consequences of a
functional failure; e.g. the existence of any standby systems, built in redundancy or emergency
operating procedures
• The specific performance requirements of each function
• All modes of operation
• Any variations in system/equipment capability due to type variants or modification states.

FAILURE MODES AND EFFECTS ANALYSIS (FMEA)

The specific format of FMEA can vary dependent on which RCM guidance is being used. The section
that follows describes generic principles that can be applied irrespective of specific guidance.
When you consider the 7 basic questions of RCM, the FMEA is the toll with which questions 1 to 4 are
answered…

1. What are the functions and associated desired standards of performance of the item in the
present operating context?
2. In what ways does the item fail to perform its function?
3. What causes each functional failure?
4. What happens when each failure occurs?

What are the functions and associated desired standards of performance of the item in
the present operating context?

An item or system will normally possess several functions, these may fit into one of several categories
as follows:
• Primary Function
• Secondary Function
• Protective Function
• Superfluous Function

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