Saturday afternoon edits
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@ -13,9 +13,9 @@ incremental and rigorous approach.
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%% What I have done
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%% What I have done
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%%
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%%
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The Four main static failure mode analysis methodologies were examined and
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The four main static failure mode analysis methodologies were examined and
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in the context of newer European safety standards, assessed.
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in the context of newer European safety standards, assessed.
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Some of the defeciencies identified in these methodologies lead to
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Some of the deficiencies identified in these methodologies lead to
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a wish list for a more ideal methodology.
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a wish list for a more ideal methodology.
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%% What I have found
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%% What I have found
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@ -29,7 +29,7 @@ methodology is developed and proposed. The has been named Failure Mode Modular D
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%% Sell it
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%% Sell it
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%%
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%%
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In addition to addressing the traditional weaknesses of
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In addition to addressing the traditional weaknesses of
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Fault Tree Analysis (FTA), Fault Mode Effects Analysis (FMEA), Failure Mode Effects Criticallity Analysis (FMECA)
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Fault Tree Analysis (FTA), Fault Mode Effects Analysis (FMEA), Failure Mode Effects Criticality Analysis (FMECA)
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and Failure Mode Effects and Diagnostic Analysis (FMEDA), FMMD provides the means to model multiple failure mode scenarios
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and Failure Mode Effects and Diagnostic Analysis (FMEDA), FMMD provides the means to model multiple failure mode scenarios
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as specified in newer European Safety Standards \cite{en298}.
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as specified in newer European Safety Standards \cite{en298}.
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The proposed methodology is bottom-up and can guarantee to leave no component failure mode unhandled.
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The proposed methodology is bottom-up and can guarantee to leave no component failure mode unhandled.
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@ -47,7 +47,7 @@ incremental and rigorous approach.
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%% What I have done
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%% What I have done
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%%
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%%
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The Four main static failure mode analysis methodologies were examined and
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The four main static failure mode analysis methodologies were examined and
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in the context of newer European safety standards, assessed.
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in the context of newer European safety standards, assessed.
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Some of the defeciencies identified in these methodologies lead to
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Some of the defeciencies identified in these methodologies lead to
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a wish list for a more ideal methodology.
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a wish list for a more ideal methodology.
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@ -63,7 +63,7 @@ methodology is developed and proposed. The has been named Failure Mode Modular D
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%% Sell it
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%% Sell it
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%%
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%%
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In addition to addressing the traditional weaknesses of
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In addition to addressing the traditional weaknesses of
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Fault Tree Analysis (FTA), Fault Mode Effects Analysis (FMEA), Failure Mode Effects Criticallity Analysis (FMECA)
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Fault Tree Analysis (FTA), Fault Mode Effects Analysis (FMEA), Failure Mode Effects Criticality Analysis (FMECA)
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and Failure Mode Effects and Diagnostic Analysis (FMEDA), FMMD provides the means to model multiple failure mode scenarios
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and Failure Mode Effects and Diagnostic Analysis (FMEDA), FMMD provides the means to model multiple failure mode scenarios
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as specified in newer European Safety Standards \cite{en298}.
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as specified in newer European Safety Standards \cite{en298}.
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The proposed methodology is bottom-up and can guarantee to leave no component failure mode unhandled.
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The proposed methodology is bottom-up and can guarantee to leave no component failure mode unhandled.
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@ -78,7 +78,7 @@ It is also modular, meaning that the results of analysed components may be re-us
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There are four methodologies in common use for failure mode modelling.
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There are four methodologies in common use for failure mode modelling.
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These are FTA, FMEA, FMECA
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These are FTA, FMEA, FMECA
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and FMEDA (a form of statistical assessment).
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and FMEDA (a form of statistical assessment).
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%
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These methodologies date from the 1940's onwards, and were designed for
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These methodologies date from the 1940's onwards, and were designed for
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different application areas and reasons; all have drawbacks and
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different application areas and reasons; all have drawbacks and
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advantages that are discussed in the next section.
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advantages that are discussed in the next section.
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@ -160,12 +160,12 @@ are held in a computer program, we can determine if the model is complete
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%%- then from that determine how it will react with other components
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%%- then from that determine how it will react with other components
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%%- and how it will be affected
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%%- and how it will be affected
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\subsection{General Comments on bottom-up and top down approaches}
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\subsection{General comments on bottom-up and top down approaches}
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\paragraph{A general defeciency in top-down systems analysis.}
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\paragraph{A general defeciency in top-down systems analysis.}
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With a top down approach the investigator has to determine
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With a top down approach the investigator has to determine
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a set of undesirable outcomes or `accidents'.
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a set of undesirable outcomes or `accidents'.
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As most accidents are unexpected and the causes unforseen \cite{safeware}
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As most accidents are unexpected and the causes unforeseen \cite{safeware}
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it is fair to say that a top down approach is not guaranteed to
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it is fair to say that a top down approach is not guaranteed to
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predict all possible undesirable outcomes.
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predict all possible undesirable outcomes.
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It also can miss known component failure modes, by
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It also can miss known component failure modes, by
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@ -249,7 +249,7 @@ of missing component failure modes \cite{faa}[Ch.9].
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FTA was invented for use on the minuteman nuclear defence missile
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FTA was invented for use on the minuteman nuclear defence missile
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systems in the early 1960s and was not designed as a rigorous
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systems in the early 1960s and was not designed as a rigorous
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fault/failure mode methodology.
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fault/failure mode methodology.
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It was designed to look for disasterous top level hazards and
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It was designed to look for disastrous top level hazards and
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determine how they could be caused.
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determine how they could be caused.
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It is more like a structure to
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It is more like a structure to
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be applied when discussing the safety of a system, with a top down hierarchical
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be applied when discussing the safety of a system, with a top down hierarchical
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@ -266,7 +266,7 @@ system level outcomes.
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\subsubsection{ FTA weaknesses }
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\subsubsection{ FTA weaknesses }
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\begin{itemize}
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\begin{itemize}
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\item Possibility to miss component failure modes
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\item Possibility to miss component failure modes
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\item Possibility to miss environmetal affects.
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\item Possibility to miss environmental affects.
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\item No possibility to model base component level double failure modes.
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\item No possibility to model base component level double failure modes.
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\end{itemize}
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\end{itemize}
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@ -279,7 +279,7 @@ The investigation will typically point to a particular failure
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of a component.
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of a component.
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The methodology is now applied to find the significance of the failure.
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The methodology is now applied to find the significance of the failure.
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Its is based on a simple equation where $S$ ranks the severity (or cost \cite{bfmea}) of the identified SYSTEM failure,
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Its is based on a simple equation where $S$ ranks the severity (or cost \cite{bfmea}) of the identified SYSTEM failure,
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$O$ its occurance, and $D$ giving the failures detectability. Muliplying these
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$O$ its occurrance, and $D$ giving the failures detectability. Muliplying these
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together,
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together,
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gives a risk probability number (RPN), given by $RPN = S \times O \times D$.
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gives a risk probability number (RPN), given by $RPN = S \times O \times D$.
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This gives in effect
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This gives in effect
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@ -289,12 +289,12 @@ a prioritised `todo list', with higher the $RPN$ values being the most urgent.
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\subsubsection{ FMEA weaknesses }
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\subsubsection{ FMEA weaknesses }
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\begin{itemize}
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\begin{itemize}
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\item Possibility to miss the effects of failure modes at SYSTEM level.
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\item Possibility to miss the effects of failure modes at SYSTEM level.
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\item Possibility to miss environemtal affects.
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\item Possibility to miss environmental effects.
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\item No possibility to model base component level double failure modes.
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\item No possibility to model base component level double failure modes.
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\end{itemize}
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\end{itemize}
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\paragraph{note.} FMEA is sometimes used in its literal sense, that is to say
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\paragraph{note.} FMEA is sometimes used in its literal sense, that is to say
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failure Mode effects Analysis, simply looking at a systems internal failure
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Failure Mode Effects analysis, simply looking at a systems internal failure
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modes and determing what may happen as a result.
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modes and determing what may happen as a result.
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FMEA described in this section (\ref{pfmea}) is sometimes called `production FMEA'.
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FMEA described in this section (\ref{pfmea}) is sometimes called `production FMEA'.
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@ -306,7 +306,7 @@ and traces them to the SYSTEM level failures.
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%
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%
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Reliability data for components is used to predict the
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Reliability data for components is used to predict the
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failure statistics in the design stage.
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failure statistics in the design stage.
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A openly published source for the reliability of generic
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An openly published source for the reliability of generic
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electronic components was published by the DOD
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electronic components was published by the DOD
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in 1991 (MIL HDK 1991 \cite{mil1991}) and is a typical
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in 1991 (MIL HDK 1991 \cite{mil1991}) and is a typical
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source for MTFF data.
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source for MTFF data.
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@ -323,7 +323,9 @@ assigned a probability $\beta$ factor by the design engineer. The use of a $\be
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is often justified using bayes theorem \cite{probstat}.
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is often justified using bayes theorem \cite{probstat}.
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%Also, it can miss combinations of failure modes that will cause SYSTEM level errors.
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%Also, it can miss combinations of failure modes that will cause SYSTEM level errors.
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%
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%
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The results, as with FMEA are an $RPN$ number determining the significance of the SYSTEM fault.
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The results of FMECA are similar to FMEA, in that component errors are
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listed according to importance of fixing it to prevent the SYSTEM fault of given criticallity.
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Again this essentially produces a prioritised todo list.
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%%-WIKI- Failure mode, effects, and criticality analysis (FMECA) is an extension of failure mode and effects analysis (FMEA).
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%%-WIKI- Failure mode, effects, and criticality analysis (FMECA) is an extension of failure mode and effects analysis (FMEA).
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%%-WIKI- FMEA is a a bottom-up, inductive analytical method which may be performed at either the functional or
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%%-WIKI- FMEA is a a bottom-up, inductive analytical method which may be performed at either the functional or
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@ -349,11 +351,13 @@ Failure Modes, Effects, and Diagnostic Analysis (FMEDA).
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This is a process that takes all the components in a system,
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This is a process that takes all the components in a system,
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and using the failure modes of those components, the investigating engineer
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and using the failure modes of those components, the investigating engineer
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ties them to possible SYSTEM level events/failure modes.
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ties them to possible SYSTEM level events/failure modes.
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%
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This technique
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This technique
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evaluates a products statistical level of safety
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evaluates a products statistical level of safety
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taking into account its self-diagnostic ability.
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taking into account its self-diagnostic ability.
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The calculations and procedures for FMEDA are
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The calculations and procedures for FMEDA are
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described in EN61508 Part 2 Appendix C \cite{en61508}[Part 2 App C].
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described in EN61508 %Part 2 Appendix C
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\cite{en61508}[Part 2 App C].
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The following gives an outline of the procedure.
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The following gives an outline of the procedure.
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@ -362,11 +366,11 @@ FMEDA is a statistical analysis methodology is used from one of two perspectives
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Probability of Failure on Demand (PFD), and Probability of Failure
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Probability of Failure on Demand (PFD), and Probability of Failure
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in continuous Operation, or Failure in Time (FIT).
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in continuous Operation, or Failure in Time (FIT).
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\paragraph{Failure in Time (FIT).} Continuous operation is measured in failures per billion ($10^9$) hours of operation.
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\paragraph{Failure in Time (FIT).} Continuous operation is measured in failures per billion ($10^9$) hours of operation.
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For a continuously running nuclear powerstation
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For a continuously running nuclear powerstation, industrial burner or aircraft engine
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we would be interested in its operational FIT values.
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we would be interested in its operational FIT values.
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\paragraph{Probability of Failure on Demand (PFD).} For instance with an anti-lock system in
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\paragraph{Probability of Failure on Demand (PFD).} For instance with an anti-lock system in
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automobile braking, we would be interested in PFD.
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automobile braking, or other fail safe measure applied in an emergency, we would be interested in PFD.
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That is to say the ratio of it failing
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That is to say the ratio of it failing
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to succeeding on demand.
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to succeeding on demand.
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@ -379,14 +383,14 @@ Each component is analysed in terms of how its failure
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would affect the system.
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would affect the system.
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Failure rates of individual components in the SYSTEM
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Failure rates of individual components in the SYSTEM
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are calculated based on component type and
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are calculated based on component type and
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environmental conditions.
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environmental conditions. The SYSTEM errors are categorised as `safe' or `dangerous'.
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%
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%
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%Statistical data exists for most component types \cite{mil1992}.
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%Statistical data exists for most component types \cite{mil1992}.
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%
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%
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This phase is typically implemented on a spreadsheet
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This phase is typically implemented on a spreadsheet
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with rows representing each component. A typical component spreadshet row would
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with rows representing each component. A typical component spreadshet row would
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comprise of
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comprise of
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component type, placing in the system, part number, environmental stress factors, MTTF etc.
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component type, placing in the system, part number, environmental stress factors, MTTF, safe/dangerous etc.
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%will be a determination of whether the component failing will lead to a `safe'
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%will be a determination of whether the component failing will lead to a `safe'
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%or `unsafe' condition.
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%or `unsafe' condition.
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@ -397,7 +401,7 @@ components in an FMEDA spreadsheet.
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%This is the sum of safe and unsafe
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%This is the sum of safe and unsafe
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%failures.
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%failures.
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\paragraph{Self Diagnostics}
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\paragraph{Self Diagnostics.}
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We next evaluate the SYSTEM's self-diagnostic ability.
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We next evaluate the SYSTEM's self-diagnostic ability.
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%Each component’s failure modes and failure rate are now available.
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%Each component’s failure modes and failure rate are now available.
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@ -411,7 +415,7 @@ we can now now classify these in terms of safe and dangerous lambda values.
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Detectable failure probabilities are labelled `$\lambda_D$' (for
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Detectable failure probabilities are labelled `$\lambda_D$' (for
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dangerous) and `$\lambda_S$' (for safe) \cite{EN61508}.
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dangerous) and `$\lambda_S$' (for safe) \cite{EN61508}.
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\paragraph{Determine Detectable and Undetecable Failures.}
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\paragraph{Determine Detectable and Undetectable Failures.}
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Each safe and dangerous failure mode is now
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Each safe and dangerous failure mode is now
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classified as detectable or un-detectable, this
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classified as detectable or un-detectable, this
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is determined by the SYSTEM’s
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is determined by the SYSTEM’s
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@ -494,7 +498,7 @@ There are four SIL levels, from 1 to 4 with 4 being the highest safety level.
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In addition to probablistic risk factors, the
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In addition to probablistic risk factors, the
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diagnostic coverage and SFF
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diagnostic coverage and SFF
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have threshold bands beoming stricter for each level.
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have threshold bands beoming stricter for each level.
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Demanded software techniques and constraints
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Demanded software verification and specification techniques and constraints (such as language sub-sets, s/w redundancy etc)
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become stricter for each SIL level.
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become stricter for each SIL level.
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Thus FMEDA uses statistical methods to determine
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Thus FMEDA uses statistical methods to determine
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@ -524,7 +528,7 @@ sub-systems are meaningless, and the nearest equivalent would be the FIT/PFD and
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\subsubsection{FMEDA and failure outcome prediction accuracy.}
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\subsubsection{FMEDA and failure outcome prediction accuracy.}
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This suffers from the same problems of
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FMEDA suffers from the same problems of
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lack of component failure mode outcome prediction accuracy, as FMEA in section \ref{pfmea}.
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lack of component failure mode outcome prediction accuracy, as FMEA in section \ref{pfmea}.
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%
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%
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This is because the analyst has to decide how particular components failing will impact on the SYSTEM or top level.
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This is because the analyst has to decide how particular components failing will impact on the SYSTEM or top level.
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@ -645,17 +649,17 @@ this methodology must start at the bottom, with base component failure modes.
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In this way automated checking can be applied to all component failure modes
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In this way automated checking can be applied to all component failure modes
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to ensure none have been inadvertently excluded from the process.
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to ensure none have been inadvertently excluded from the process.
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\paragraph{Problem with functional group hierarchy.}
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\paragraph{Problems with functional group hierarchy.}
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A hierarchy of functional grouping, leading to a system model
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A hierarchy of functional grouping, leading to a system model
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still leaves us with the problem of the number of component failure modes.
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still leaves us with the problem of the number of component failure modes.
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The base components will typically have several failure modes each.
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The base components will typically have several failure modes each.
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%
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%
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Given a typical embedded system may have hundreds of components
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Given a typical embedded system may have hundreds of components
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This means that we have to tie base component failure modes
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This means that we would still have to tie base component failure modes
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to SYSTEM level errors. This is the `possibility to miss failure mode effects
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to SYSTEM level errors. This is the `possibility to miss failure mode effects
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at SYSTEM level' criticism of the FTA, FMEDA and FMECA methodologies.
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at SYSTEM level' criticism of the FTA, FMEDA and FMECA methodologies.
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\paragraph{Design Decision: Methodolgy must reduce and collate errors at each functional group stage.}
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\paragraph{Design Decision: Methodology must reduce and collate errors at each functional group stage.}
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SYSTEMS typically have far fewer failure modes than the sum of their component failure modes.
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SYSTEMS typically have far fewer failure modes than the sum of their component failure modes.
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SYSTEM level failures may be caused by a variety of component failure modes.
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SYSTEM level failures may be caused by a variety of component failure modes.
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A SYSTEM level failure mode is an abstracted failure mode, in that
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A SYSTEM level failure mode is an abstracted failure mode, in that
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@ -693,24 +697,34 @@ It would be better to analyse the failure mode behaviour of each
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functional group, and determine the ways in which it, rather than its
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functional group, and determine the ways in which it, rather than its
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components, can fail.
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components, can fail.
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%
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%
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By doing this, the natural process whereby symptoms of the {\fg},
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By doing this, the natural process whereby symptoms of the {\fg}
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which can potentially be caused by more then one
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(which can potentially be caused by more then one component failure mode)
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component failure mode, become the target for reducing the number
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are extracted.
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%
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The number of symptoms will be less than or equal to the number
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component failure modes, and in practise will be much less.
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%
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The symptoms thus become the objects used to reduce the number
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of failure modes to handle as we traverse up the hierarchy.
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of failure modes to handle as we traverse up the hierarchy.
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\paragraph{Component failures and {\fg} failure symptoms.}
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\paragraph{Component failures and {\fg} failure symptoms.}
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In other words we want to find out what the symptoms of the failures in the {\fg}s
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In other words we want to find out what the symptoms of the failures in the {\fg}s
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are.
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are.
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The number of symptoms of failure should be equal to or
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%The number of symptoms of failure should be equal to or
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less than the number of component failure modes, simply because
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%less than the number of component failure modes, simply because
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often there are several potential causes of failure symptoms.
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%often there are several potential causes of failure symptoms.
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%
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%
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When we have the symptoms, we can start thinking of the {\fg} as a component in its own right.
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When we have the symptoms, we can start thinking of the {\fg} as a component in its own right.
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%with a simplified and reduced set of failure symptoms.
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%with a simplified and reduced set of failure symptoms.
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%
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%
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We can now create a new {\dc}, where its failure modes
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We can now create a new {\dc}, where its failure modes
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are the failure symptoms of the {\fg}.
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are the failure symptoms of the {\fg}.
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%
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By taking {\dcs} to form higher level functional groups
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we can build a bottom-up model incrementally.
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In this way as we build the hierarchy, we naturally abstract the
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In this way as we build the hierarchy, we naturally abstract the
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failure mode behaviour, but can check that all failure modes in
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failure mode behaviour, but can check that all failure modes in
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the hierarchy have been considered and tied to causing symptoms.
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the hierarchy have been considered and tied to causing symptoms.
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@ -784,7 +798,7 @@ Secondly we can say that no component may be derived from itself.
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Because common symptoms are being collected, as we build the tree up-ward
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Because common symptoms are being collected, as we build the tree up-ward
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the number of failure modes decreases (or exceptionally stays the same) at each level.
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the number of failure modes decreases (or exceptionally stays the same) at each level.
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%
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%
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This decreasing of the number of failure modes is bourne out {\irl}.
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This decreasing of the number of failure modes is borne out {\irl}.
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Of the thousands of component failure modes in a typical product
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Of the thousands of component failure modes in a typical product
|
||||||
there are generally only a handful of SYSTEM level failure modes
|
there are generally only a handful of SYSTEM level failure modes
|
||||||
(or top level `symptoms' of underlying failures).
|
(or top level `symptoms' of underlying failures).
|
||||||
@ -795,14 +809,15 @@ there are generally only a handful of SYSTEM level failure modes
|
|||||||
FMMD builds {\fg}s of components from the bottom-up.
|
FMMD builds {\fg}s of components from the bottom-up.
|
||||||
The lowest level of components are termed base components.
|
The lowest level of components are termed base components.
|
||||||
These are the initial building blocks.
|
These are the initial building blocks.
|
||||||
In Electronics these would be the individual
|
In electronics these would be the individual
|
||||||
passive and active components on the parts~list.
|
passive and active components on the parts~list.
|
||||||
In mechanics the the levers springs cogs etc.
|
In mechanics the levers, linkages, springs and cogs etc.
|
||||||
|
%
|
||||||
Functional groups are collections of components
|
Functional groups are collections of components
|
||||||
that work together to perform a simple function.
|
that work together to perform a simple function.
|
||||||
%
|
%
|
||||||
We can perform a failure mode effects analysis on each of the component failure
|
We can perform a failure mode effects analysis on each of the component failure
|
||||||
modes within the {\fg}. We can thus ensure that all component failure modes
|
modes within a {\fg}. Because we can implemnent the process in software we can thus ensure that all component failure modes
|
||||||
are covered.
|
are covered.
|
||||||
%
|
%
|
||||||
We can then treat the {\fg} as a `black box' or component in its own right.
|
We can then treat the {\fg} as a `black box' or component in its own right.
|
||||||
@ -847,13 +862,15 @@ create higher level {\fg}s in later stages.
|
|||||||
% \vspace{20pt}
|
% \vspace{20pt}
|
||||||
|
|
||||||
|
|
||||||
\subsection{Environmental Conditoions, Operational States and FMMD}
|
\subsection{Environmental Conditions, Operational States and FMMD}
|
||||||
|
|
||||||
Any real world sub-system will exist in a variable environment and may have several modes of operation.
|
Any real world sub-system will exist in a variable environment and may have several modes of operation.
|
||||||
In order to find all possible failures, the sub-system must be analysed for each operational state
|
In order to find all possible failures, the sub-system must be analysed for each operational state
|
||||||
and environment condition that can affect it.
|
and environment condition that can affect it.
|
||||||
Two design decision are required here, which objects should we
|
%
|
||||||
|
Two design decisions are required here, which objects should we
|
||||||
analyse the environment and operational states with respect to.
|
analyse the environment and operational states with respect to.
|
||||||
|
we have three objects in our model that these considerations could be applied to.
|
||||||
We could apply these conditions for analysis
|
We could apply these conditions for analysis
|
||||||
to the functional group, the components, or the derived
|
to the functional group, the components, or the derived
|
||||||
component.
|
component.
|
||||||
@ -861,9 +878,9 @@ component.
|
|||||||
\paragraph {Environmental Conditions and FMMD.}
|
\paragraph {Environmental Conditions and FMMD.}
|
||||||
|
|
||||||
Environmental conditions are external to the
|
Environmental conditions are external to the
|
||||||
{\fg} and are often things that the system has no direct control over.
|
{\fg} and are often things the system has no direct control over.
|
||||||
Consider ambient temperature, pressure or even electrical interferrence levels.
|
Consider ambient temperature, pressure or even electrical interference levels.
|
||||||
|
%
|
||||||
Environmental conditions may affect different components in a {\fg}
|
Environmental conditions may affect different components in a {\fg}
|
||||||
in different ways.
|
in different ways.
|
||||||
|
|
||||||
@ -872,19 +889,20 @@ For instance a system may be specified for
|
|||||||
may show failure behaviour between 60 and 85
|
may show failure behaviour between 60 and 85
|
||||||
\footnote{Opto-islolators typically show marked performace decrease after
|
\footnote{Opto-islolators typically show marked performace decrease after
|
||||||
60oC whereas another common component, the resistor will be unaffected.}.
|
60oC whereas another common component, the resistor will be unaffected.}.
|
||||||
|
Other components may operate comfortably within that whole temperature range specified.
|
||||||
Environmental conditions will have an effect on the {\fg} and the {\dc}
|
Environmental conditions will have an effect on the {\fg} and the {\dc}
|
||||||
but they will have specific effects on individual components.
|
but they will have specific effects on individual components.
|
||||||
|
|
||||||
\paragraph{Design Decision.}
|
\paragraph{Design Decision.}
|
||||||
Environmental constraints will be applied to components.
|
Environmental constraints will be applied to components.
|
||||||
A component will hold a set of Environmental states that
|
A component will hold a set of environmental states that
|
||||||
affect it.
|
affect it.
|
||||||
Environmental conditions will apply SYSTEM wide,
|
Environmental conditions will apply SYSTEM wide,
|
||||||
but may only affect specific components.
|
but may only affect specific components.
|
||||||
%Some may not be required for consideration
|
%Some may not be required for consideration
|
||||||
%for the analysis of particular systems.
|
%for the analysis of particular systems.
|
||||||
|
|
||||||
\paragraph {Operational States and FMMD}
|
\paragraph {Operational States and FMMD.}
|
||||||
|
|
||||||
Sub-systems may have specific operational states.
|
Sub-systems may have specific operational states.
|
||||||
These could be a general health level such as
|
These could be a general health level such as
|
||||||
@ -947,7 +965,7 @@ component level failure modes. This provides causation trees \cite{sccs} or, min
|
|||||||
for all SYSTEM failure modes.
|
for all SYSTEM failure modes.
|
||||||
|
|
||||||
\subsubsection{ It should be capable of producing reliability and danger evaluation statistics.}
|
\subsubsection{ It should be capable of producing reliability and danger evaluation statistics.}
|
||||||
The Minimal cuts sets for the SYSTEM level failures can have computed MTTF
|
The minimal cuts sets for the SYSTEM level failures can have computed MTTF
|
||||||
and danger evaluation statistics sourced from the component failure mode statistics \cite {mil1991}.
|
and danger evaluation statistics sourced from the component failure mode statistics \cite {mil1991}.
|
||||||
|
|
||||||
\subsubsection{ It should be easy to use, ideally using a graphical syntax (as oppossed to a formal mathematical one).}
|
\subsubsection{ It should be easy to use, ideally using a graphical syntax (as oppossed to a formal mathematical one).}
|
||||||
@ -994,6 +1012,6 @@ chosing {\fg}s and working bottom-up this hierarchical trait will occur as a nat
|
|||||||
This paper provides the background for the need for a new methodology for
|
This paper provides the background for the need for a new methodology for
|
||||||
static analysis that can span the mechanical electrical and software domains
|
static analysis that can span the mechanical electrical and software domains
|
||||||
using a common notation.
|
using a common notation.
|
||||||
The author believes it addresses mant short comings in current static failure mode analysis methodologies.
|
The author believes it addresses many short comings in current static failure mode analysis methodologies.
|
||||||
\vspace{60pt}
|
\vspace{60pt}
|
||||||
\today
|
\today
|
||||||
|
@ -6,6 +6,8 @@
|
|||||||
\usepackage{amsfonts,amsmath,amsthm}
|
\usepackage{amsfonts,amsmath,amsthm}
|
||||||
\input{../style}
|
\input{../style}
|
||||||
\usepackage{ifthen}
|
\usepackage{ifthen}
|
||||||
|
\usepackage{lastpage}
|
||||||
|
|
||||||
\newboolean{paper}
|
\newboolean{paper}
|
||||||
\setboolean{paper}{true} % boolvar=true or false
|
\setboolean{paper}{true} % boolvar=true or false
|
||||||
|
|
||||||
@ -14,13 +16,21 @@
|
|||||||
|
|
||||||
\begin{document}
|
\begin{document}
|
||||||
\pagestyle{fancy}
|
\pagestyle{fancy}
|
||||||
|
\fancyhf{}
|
||||||
|
%\renewcommand{\chaptermark}[1]{\markboth{ \emph{#1}}{}}
|
||||||
|
\fancyhead[LO]{}
|
||||||
|
\fancyhead[RE]{\leftmark}
|
||||||
|
%\fancyfoot[LE,RO]{\thepage}
|
||||||
|
\cfoot{Page \thepage\ of \pageref{LastPage}}
|
||||||
|
\rfoot{\today}
|
||||||
|
\lhead{Developing a rigorous bottom-up modular static failure mode modelling methodology}
|
||||||
|
|
||||||
%\outerhead{{\small\bf Statistical Basis for Current Static Analysis Methodologies}}
|
%\outerhead{{\small\bf Developing a rigorous bottom-up modular static failure mode modelling methodology}}
|
||||||
%\innerfoot{{\small\bf R.P. Clark } }
|
%\innerfoot{{\small\bf R.P. Clark } }
|
||||||
% numbers at outer edges
|
% numbers at outer edges
|
||||||
\pagenumbering{arabic} % Arabic page numbers hereafter
|
\pagenumbering{arabic} % Arabic page numbers hereafter
|
||||||
\author{R.P.Clark}
|
\author{R.P.Clark}
|
||||||
\title{Developing A rigorous bottom-up modular static failure mode modelling methodology}
|
\title{Developing a rigorous bottom-up modular static failure mode modelling methodology}
|
||||||
\maketitle
|
\maketitle
|
||||||
\input{fmmd_concept_paper}
|
\input{fmmd_concept_paper}
|
||||||
|
|
||||||
|
15
thesis.tex
15
thesis.tex
@ -7,6 +7,7 @@
|
|||||||
\usepackage{amsfonts,amsmath,amsthm}
|
\usepackage{amsfonts,amsmath,amsthm}
|
||||||
\usepackage{algorithm}
|
\usepackage{algorithm}
|
||||||
\usepackage{algorithmic}
|
\usepackage{algorithmic}
|
||||||
|
\usepackage{lastpage}
|
||||||
|
|
||||||
%% fix for hyperref bug in algorithm package
|
%% fix for hyperref bug in algorithm package
|
||||||
\newcommand{\theHalgorithm}{\thechapter.\arabic{algorithm}}
|
\newcommand{\theHalgorithm}{\thechapter.\arabic{algorithm}}
|
||||||
@ -17,18 +18,20 @@
|
|||||||
\usepackage{hyperref}
|
\usepackage{hyperref}
|
||||||
\begin{document}
|
\begin{document}
|
||||||
\pagestyle{fancy}
|
\pagestyle{fancy}
|
||||||
|
\fancyhf{}
|
||||||
|
\cfoot{Page \thepage}
|
||||||
|
|
||||||
\input{titlepage/titlepage}
|
\input{titlepage/titlepage}
|
||||||
|
|
||||||
\clearpage
|
\clearpage
|
||||||
|
|
||||||
\rhead{{\small\bf Failure Mode Modular De-Composition}}
|
%\rhead{{\small\bf Failure Mode Modular De-Composition}}
|
||||||
\rfoot{{\small\bf PhD Thesis : R.P. Clark } }
|
%\rfoot{{\small\bf PhD Thesis : R.P. Clark } }
|
||||||
|
|
||||||
% Contents
|
% Contents
|
||||||
% --------
|
% --------
|
||||||
|
|
||||||
\cfoot{Page \thepage} % Contents page numbers centred
|
%\cfoot{Page \thepage} % Contents page numbers centred
|
||||||
|
|
||||||
\clearpage
|
\clearpage
|
||||||
%\input{colophon/colophon}
|
%\input{colophon/colophon}
|
||||||
@ -49,7 +52,11 @@
|
|||||||
%\middlefoot{ } \outerfoot{{Page \bf\thepage}} % Body of manual has bolded page
|
%\middlefoot{ } \outerfoot{{Page \bf\thepage}} % Body of manual has bolded page
|
||||||
% numbers at outer edges
|
% numbers at outer edges
|
||||||
\pagenumbering{arabic} % Arabic page numbers hereafter
|
\pagenumbering{arabic} % Arabic page numbers hereafter
|
||||||
|
\cfoot{Page \thepage\ of \pageref{LastPage}}
|
||||||
|
\lfoot{Brighton University 2011}
|
||||||
|
\rfoot{R.P.Clark \today}
|
||||||
|
\lhead{Failure Mode Modular De-Composition}
|
||||||
|
\rhead{PhD Thesis}
|
||||||
%\begin{document}
|
%\begin{document}
|
||||||
|
|
||||||
\typeout{>>--------------------->> introduction}
|
\typeout{>>--------------------->> introduction}
|
||||||
|
Loading…
Reference in New Issue
Block a user