From a55aa9698d66c1d4b46a832bc5cab6980f0f205e Mon Sep 17 00:00:00 2001 From: Robin Clark Date: Sun, 9 Sep 2012 10:50:04 +0100 Subject: [PATCH] As sent to JMC for english pr --- mybib.bib | 2 +- submission_thesis/CH4_FMMD/copy.tex | 32 ++++++++++++++++---- submission_thesis/appendixes/algorithmic.tex | 15 +++++++-- 3 files changed, 39 insertions(+), 10 deletions(-) diff --git a/mybib.bib b/mybib.bib index 83f478e..740a36b 100644 --- a/mybib.bib +++ b/mybib.bib @@ -156,7 +156,7 @@ Database number = "", pages = " ", year = "2012", - note = "Proceedings of the First International Workshop on Euler Diagrams (Euler 2004)", + note = " ", issn = "1571-0661", doi = "DOI: 10.1016/j.entcs.2005.02.018", url = "http://www.bsigroup.com/en/assessment-and-certification-services/management-systems/standards-and-schemes/iso-9001/", diff --git a/submission_thesis/CH4_FMMD/copy.tex b/submission_thesis/CH4_FMMD/copy.tex index ec8fb57..38b1c21 100644 --- a/submission_thesis/CH4_FMMD/copy.tex +++ b/submission_thesis/CH4_FMMD/copy.tex @@ -1223,6 +1223,18 @@ We can thus create a new component derived from analysing the {\fg} where % the symptoms of failure of the {\fg} are the failure modes of this new `{\dc}'. + +An outline of the FMMD process is itemised below: +\begin{itemize} + \item Collect components to form a {\fg}, + \item Create failure cause `test~cases' for all failure modes of the components within the {\fg}, + \item Analyse the effect of all the test~cases on the operation of the {\fg}, + \item Determine the common failure modes of the {\fg}, + \item Create and name a derived component for the {\fg}, + \item Assign the common failure modes from the {\fg} as the failure modes of the {\dc}. +\end{itemize} + + %We can now call our functional~group a sub-system or a derived~component. %The goal here is to know how it will behave under fault conditions ! %Imagine buying one such `sub~system' from a very honest vendor. @@ -1297,8 +1309,11 @@ The UML class diagram in figure structure with its associated failure modes. % From this diagram we see that each component must have at least one failure mode. +% To clearly show that the failure modes are mutually exclusive states, or unitary states associated with one component, -each failure mode is referenced back to only one component. This constraint is discussed in detail in section~\ref{sec:unitarystate}. +each failure mode is referenced back to only one component. +% +This constraint is discussed in detail in section~\ref{sec:unitarystate}. %%-%% MTTF STATS CHAPTER MAYBE ?? %%-%% @@ -2156,6 +2171,7 @@ we can ensure that all these {\fms} are traceable to subsequent {\dc} {\fms} in the model. % With the above condition true, we term this a `complete' FMMD failure model. +Ensuring this condition is described in section~\ref{sec:completetest}. \paragraph{State explosion problem of FMEA solved by FMMD.} % @@ -2164,18 +2180,22 @@ the traditional state explosion problem in FMEA, where each failure mode could be considered in the context of all other components in the system disappears. % -This is dealt with formally in section~\ref{sec:cc}. +This issue addressed formally in section~\ref{sec:cc}. \paragraph{Uses of the FMMD failure mode model.} % Having a failure mode graph/model, where base component failure modes are traceable to top event events, provides a forward search derived failure mode model. +A forward search means that we can apply checks to ensure that +all known component failure +modes have been considered in the analysis (i.e. completeness as described above). % -%A forward search means that we can apply checks to ensure that -%all known component failure -%modes have been considered in the analysis (i.e. completeness as described above). +This means that for every system level failure we can track back to possible causes +in the base components. Coupled with MTTF statistics for the base components +this allows use to predict statistical failure rates for system level failures (this is +described in greater detail in section~\ref{sec:determine_fms}). % -We can use this model to derive information +We can also use the FMMD model to derive information to assist in creating related models such as FTA~\cite{nucfta,nasafta}, traditional FMEA, FMECA~\cite{safeware}[p.344], FMEDA~\cite{scsh}, diagnostics schemas~\cite{dbamafta} and other failure mode analysis methodologies. \ No newline at end of file diff --git a/submission_thesis/appendixes/algorithmic.tex b/submission_thesis/appendixes/algorithmic.tex index 2a8bbcc..b9d46bd 100644 --- a/submission_thesis/appendixes/algorithmic.tex +++ b/submission_thesis/appendixes/algorithmic.tex @@ -806,9 +806,18 @@ given by $$ dtc(F) = TC $$ -In algorithm \ref{alg22}, the function \textbf{chosen} means that the failure modes for a particular test case have been chosen by -a human operator and are additional to those chosen by the automated process (i.e they are special case test cases involving multiple failure modes) -The function \textbf{unitary state} means that all test cases can have no pairs of failure modes sourced from the same component. +In algorithm \ref{alg22}, the function \textbf{chosen} means that +the failure modes for a particular test case have been chosen by +a human operator and are additional to those chosen by the automated process (i.e they are +special case test cases involving multiple failure modes) +The function \textbf{unitary state} means that all test +cases can have no pairs of failure modes sourced from the same component. + +\label{sec:completetest} + +This function also ensure completeness in the model. +It ensures that for all failure modes in the {\fg} are considered in a test~case. + \ifthenelse {\boolean{paper}} { %% perhaps ref a paper here XXXXX