Applied R&M Manual for Defence Systems
(GR-77 Issue 2011)
Part B - R&M Related Activities
The structured decomposition (Part A Chapter 4) identifies a number of
activities that are undertaken under the banner of R&M. Each activity has a purpose, in terms of
producing a given type of information, and is performed through the use of one
or more techniques (see Part C).
Chapter 1 Potential
Scenario Analysis
Potential scenarios are considered in the early stages of designing a
new system or of modifying an existing system for a new task. The effect of R&M performance parameters
on functional performance, logistical support requirements and safety can be a
key factor in determining the effectiveness of a proposed solution.
Chapter 2 R&M
Performance Specification
The achievement of R&M in service stems from either luck or a
clear, appropriate and realistic specification of the requirements together
with a contract that enforces adherence.
Various forms of specification exist and can be applied to differing
parts of the specified system. There are
also a number of pitfalls to be avoided if the specification is not to become
the subject of protracted discussion and eventual concession.
Chapter 3 Design for R&M Performance
R&M is built into a system at the design stage. No amount of analysis or testing can improve
a design without a costly revisit to the design stage. The use of good design practice for high
reliability and good field maintainability (in software and hardware) is an
essential component of reducing project risk and achieving good products. (This
chapter is presently being developed)
Chapter 4 Practical Review of Design for R&M
The functionality of a system is well tested during the design
process. The continuity of this
functionality over time and the ability to return failed equipment to a
functional state is equally relevant to achieving performance in the field. Various methods of testing are available and
can provide useful feedback on the performance. (This chapter is presently
being developed)
Chapter 5 Theoretical
Review of Design for R&M
Practical testing can only sample the failure modes of complex modern
equipment. Theoretical review and analysis
complements practical testing and identifies where the defence against rarer,
but important, situations is less than necessary or reasonably practicable.
Chapter 6 Theoretical Estimation of R&M
Performance
Predictions are perhaps the best known and most misused tools of
R&M engineering. They do have a
valuable role in the project life cycle provided they are used appropriately
and with knowledge of their shortcomings. (This chapter is presently being
developed)
Chapter 7 Failure
Consequence Analysis
The connection of failures and their effects, or conversely high level
events and their causes, provides important insights into the control of
undesirable events at the system level or beyond. A good model of the system failure modes
facilitates the identification of the area of a system to be addressed in order
to improve system R&M.
Chapter 8 Practical
Demonstration of R&M
R&M Demonstrations are practical tests of the achievement of
specified levels of R&M performance.
They can be used to verify the achievement of specified requirements and
to provide evidence to support reliability and safety cases.
Chapter 9 Production Engineering for R&M
The use of optimal practices in production (see Chapter 10) requires
engineering to determine the areas where resources can be most effectively
applied. (This chapter is presently being developed)
Chapter 10 R&M Evidence Collation
Evidence of the level of R&M performance provided is required for
the initial acceptance of a system into service or even its continued use. Such evidence may also be required to support
the safety case for the system or an assessment of the system’s fitness for a
given use. (This chapter is presently being developed)
Chapter 11 R&M in Production and Maintenance
The use of less than optimal practices in the assembly process has been
identified as a major contributor to poor R&M performance in the
field. It is therefore an important area
to address if a product is to achieve its intrinsic reliability. (This chapter
is presently being developed)
Chapter 12 Cautions
and Precautions in the Use of In-Service R&M Data
The process of gathering data from in-service equipment is very
beneficial to the performance of both current and future equipment. However such a process is fruitless unless
all the relevant data is collected, stored and analysed.
Chapter 13 Project Management and R&M
R&M should be addressed by project management. R&M projects should be project managed. There are however some areas that require
special consideration given the long term focus of R&M activities. These include: the use, and time taken by,
statistical tests; the more abstract / statistical nature of the quantities
involved; and the differences between passing R&M aspects and functional /
environmental aspects on to sub-contractors. (This chapter is presently being
developed)
Chapter 14 R&M Data Management
R&M is a data intensive subject.
Predictions specifically use past data.
Often the quality of the information produced by an R&M activity is
directly related to the quality of information available. The management of data, particularly historic
data from other system, is key to engineering success in the future. (This
chapter is presently being developed)
Chapter 15 Software
R&M Analysis
This chapter discusses the techniques appropriate to the analysis,
assessment and progressive assurance of the R&M characteristics of
software. Techniques to be applied during
each phase of the system’s Life Cycle that assist the development and
maintenance of software with adequate integrity and their application are
discussed which are often interactive and iterative.
Chapter 16 Representing
the Initial R&M Case Using Goal Structuring Notation
This chapter provides a discussion of how the Initial R&M Case may
be represented using Goal Structuring Notation (GSN). The approach may be equally used to present
any situation where one wishes to make a claim and where the support for that
claim will be based upon evidence and argument.
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