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Robin Clark 2013-04-01 11:11:13 +01:00
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submission_thesis/CH3_FMEA_criticism/copy.tex
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@ -131,7 +131,17 @@ Although this
would give a better picture of the failure mode behaviour, it would give a better picture of the failure mode behaviour, it
is by no means a rigorous approach to tracing errors that may occur in hardware is by no means a rigorous approach to tracing errors that may occur in hardware
through to the top (and therefore ultimately controlling) layer of software. through to the top (and therefore ultimately controlling) layer of software.
%
With the increasing use of micro-controllers in place of analogue electronics
for most new designs of electronic product, the poor integration capabilities of FMEA
are now being seen as deficiencies.
This apparent then in the dilemma now faced
by organisations dealing with highly safety critical systems, and having rely on `smart~instruments'
that they can no longer validate using FMEA.
Smart instruments are dealt with in the section below.
Distributed real time systems, which rely on micro-controllers connected in a network
using a communications protocol, are also impossible to be meaningfully analysed by FMEA.
\subsection{The rise of the smart instrument} \subsection{The rise of the smart instrument}
%% AWE --- Atomic Weapons Establishment have this problem.... %% AWE --- Atomic Weapons Establishment have this problem....
@ -228,10 +238,14 @@ utterly anachronistic in the distributed real time system environment.
\item Difficult to re-use previous analysis work \item Difficult to re-use previous analysis work
\item Very Difficult to model simultaneous failures. \item Very Difficult to model simultaneous failures.
\item Software and hardware models are separate. \item Software and hardware models are separate.
\item Distributed real time systems are very difficult to meaningfully analyse with FMEA. \item Distributed real time systems are very difficult to analyse with FMEA because they typically involve many hardware/software interfaces.
\end{itemize} \end{itemize}
FMEA is no longer fit for purpose! Traditional forms of FMEA are no longer % fit for purpose!
of meaningful use for modern systems incorporating programmatic elements.
They were designed to analyse simple electro-mechanical systems
and even the commonplace large integrated analogue circuits (that are physically small), are
getting to complicated for meaningful analysis using FMEA.
% %
% %
% \section{Conclusions on current FMEA Methodologies} % \section{Conclusions on current FMEA Methodologies}