diff --git a/submission_thesis/appendixes/algorithmic.tex b/submission_thesis/appendixes/algorithmic.tex index 4c1b683..9811c66 100644 --- a/submission_thesis/appendixes/algorithmic.tex +++ b/submission_thesis/appendixes/algorithmic.tex @@ -26,7 +26,7 @@ The FMMD process is described in chapter~\ref{sec:chap4}. \item collection of components to form {\fgs}, \item applying FMEA to the {\fgs}, \item collecting common symptoms from the FMEA results, - \item creating a {\dc} representing the failure mode behaviour of the {\fg}. + \item creating a {\dc} modelling the failure mode behaviour of the {\fg}. \end{itemize} % \fmmdgloss @@ -283,10 +283,13 @@ The algorithm, represented by the symbol `$\derivec$', is described using five a The symptom abstraction process allows us to take a {\fg} of components, analyse the failure mode behaviour and create a new entity, a {\dc} that has its own set of failure modes. +% The checks and constraints applied in the algorithm ensure that all component failure modes are covered. +% This process provides the analysis `step' to building a hierarchical failure mode model from the bottom-up. +% \fmmdgloss @@ -331,7 +334,9 @@ test cases must next be determined. %we now need to determine test cases. % The test cases are collections of failure modes. +% These can be formed from single failure modes or failure modes in combination. +% Let $\mathcal{TC}$ be the set of all test cases, $\mathcal{F}$ be the set of all failure modes. %(associated with the functional group $FG$). @@ -378,9 +383,9 @@ all failure modes in components in the {\fg} are included in at least one test~c component failures are investigated with some specially selected combination faults} - \State { Let $TC$ be the set of test cases } + \State { Let $TC$ be a set of test cases } \Comment {this set is used to collect the test cases} \State { Let $tc_j$ be a set of component failure modes where $j$ is an index of $J$} - \Comment { Each set $tc_j$ is a `test~case' and $TC = \bigcup_{j \in J} \{tc_j\}$ where $J \in \mathbb{N}_{+}$ } + \Comment { Each set $tc_j$ is a `test~case' and $TC = \bigcup_{j \in J} \{tc_j\}$ where $J \subset \mathbb{N}_{+}$ } \State { $ TC := \emptyset $ } \Comment{Initialise set of test cases} \State { $ j := 1 $ } \Comment{Initialise index of test cases} @@ -437,14 +442,14 @@ all failure modes in components in the {\fg} are included in at least one test~c \State { let $f$ represent a component failure mode } %\ENSURE { That all failure modes are represented in at least one test case } \Ensure { $ \forall f \;such\;that\; (f \in F)) \wedge (f \in \bigcup TC) $ } - \Comment { Check that at each single failure mode is + \Comment { Check that at each single failure mode in the {\fg} is included as a test case.} %\EndIf %\If{Double fault checking} \State { let $f1,f2$ represent component failure modes, and $c$ any component in the functional group } %\ENSURE { That all failure modes are represented in at least one test case } \Ensure { $ \forall f1,f2 \;where\; (f1 \wedge f2) \not\in (\forall c) \;such\;that\; (f1,f2 \in F)) \wedge ( \{f1,f2\} \in \bigcup TC) \wedge ({DoubleFaultChecking} = TRUE)$ } - \Comment { If ${DoubleFaultChecking}$ is required, check that all possible double failure modes (see section~\ref{sec:unitarystate}) are included + \Comment { If ${DoubleFaultChecking}$ is required, check that all possible double failure modes in the {\fg} (see section~\ref{sec:unitarystate}) are included as a test cases.} \State \textbf{return} $TC$ \end{algorithmic} @@ -505,6 +510,7 @@ The analysis is primarily a human activity. Calculations or simulations are performed to determine how the failure modes in each test case will affect the functional~group. +% Ideally field data and/or formal physical testing should be used in addition to static failure mode reasoning where possible. % @@ -525,7 +531,9 @@ A set of results corresponding to our test cases is now available. % These share a common index value ($j$ in the algorithm description). +% These results are the failure modes of the {\fg}. +% \fmmdgloss %Once a functional group has been analysed, it can be re-used in %any other design that uses it.