..

fmmd_data_model/fmmd_data_model.tex

@@ -174,7 +174,7 @@ Graph (DAG).
 %  \label{fig:cfg2fmmd_data}
 % \end{figure}
 
-\pagebreak[4]
+%\pagebreak[4]
 \subsection{Find Failure Modes}
 
 Consider the SYSTEM environment with its temperature range of ${{0}\oc}$ to ${{125}\oc}$.
@@ -186,7 +186,7 @@ gives the following failure modes, $fm(K) =\{ K^0_a, K^0_b, K^0_d \}$.
 Were our system specified for a ${{0}\oc}$ to ${{80}\oc}$  range
 we could say $fm(K) =\{ K^0_a, K^0_b \}$.
 
-\pagebreak[3]
+%\pagebreak[3]
 \paragraph{Get the failure modes from the functional groups.}
 Applying the function $fm$ to our functional groups, with the SYSTEM environmental
 constraint applied to component type `K',  yields
@@ -408,7 +408,7 @@ We can represent $ C^1_1 $ as an addition to the DAG (see figure \ref{fig:dag1})
  \label{fig:dag1}
  \end{figure}
 
-\clearpage
+%n\clearpage
 \subsection{ Creating Derived components from $FG^0_2$ and $FG^0_3$ }
 
 Applying the FMMD process for $FG^0_2$ and $FG^0_3$.
@@ -703,10 +703,10 @@ This is shown in the DAG in figure \ref{fig:dag3}.
 
 
 
-\clearpage
+%\clearpage
 %\pagebreak[4]
 \subsection{Using Derived Components in Functional Groups}
-
+\label{dagexample}
 The DAG we have in figure \ref{fig:dag3} does not yet give us SYSTEM or `top~level'
 failure modes.
 We can apply $fm$ to the derived components and 
@@ -976,22 +976,24 @@ at low temperatures.
 What we have is an inhibit condition, in this case the temperature 
 being in range makes the particular failure mode impossible.
 
+%[regular polygon,regular polygon sides=9]
 
  \begin{figure}
  \centering
  \begin{tikzpicture}[shorten >=1pt,->,draw=black!50, node distance=\layersep]
      \tikzstyle{every pin edge}=[<-,shorten <=1pt]
      \tikzstyle{fmmde}=[circle,fill=black!25,minimum size=17pt,inner sep=0pt]
-     \tikzstyle{fmmdi}=[rectangle,fill=black!25,minimum size=17pt,inner sep=0pt]
+     \tikzstyle{fmmdi}=[regular polygon,regular polygon sides=6,fill=black!25,minimum size=17pt,inner sep=0pt]
+     %\tikzstyle{fmmdi}=[rectangle,fill=black!25,minimum size=17pt,inner sep=0pt]
      \tikzstyle{component}=[fmmde, fill=green!50];
      \tikzstyle{failure}=[fmmde, fill=red!50];
      \tikzstyle{symptom}=[fmmde, fill=blue!50];
-     \tikzstyle{inhibit}=[fmmdi, fill=grey!20];
+     \tikzstyle{inhibit}=[fmmdi, fill=black!20];
      \tikzstyle{conjunction}=[fmmde, fill=red!20];
      \tikzstyle{annot} = [text width=4em, text centered]
 
  	\node[component] (C-1) at (0,-2) {$C^0_1$};
- 	\node[fmmdi] (I-1) at (\layersep,-2) {$ > 80\oc$};
+ 	\node[inhibit] (I-1) at (\layersep,-2) {$ > 80\oc$};
         \path (C-1) edge (I-1);
         \node[failure] (f) at (\layersep*2,-2)  {$a$}; 
         \path (I-1) edge (f);
@@ -1004,7 +1006,7 @@ being in range makes the particular failure mode impossible.
 
 \subsection{Conjunction}
 
-Failure conjuction is simply considering, at the {\fg} analysis stage
+Failure conjunction is simply considering, at the {\fg} analysis stage
 the possibility of two components failing within the same timeframe.
 We could for instance, looking at a fuel train to a burner/chemical~reactor;
 consider both shutoff valves failing at the same time.
@@ -1044,8 +1046,8 @@ simultaneous failures may have to be considered \cite{en298}.
 
  \end{tikzpicture}
  % End of code
- \caption{DAG representing conjuction condition on failure modes $a \wedge b \wedge c$}
+ \caption{DAG representing conjunction condition on failure modes $a \wedge b \wedge c$}
- \label{fig:dagconjuction}
+ \label{fig:dagconjunction}
 \end{figure}
 
 \subsection{Failure Mode Conjuction Conditions represented in the DAG}
@@ -1096,20 +1098,185 @@ Show how FMMD makes this tracable
 % clear the page if its a paper to keep the diagram out of the references
 \ifthenelse {\boolean{paper}}
 {
-\clearpage
+%\clearpage
 }
 {
 }
 
  
-\section{Current Static Failure Mode Methodologies}
+\pagebreak[3]
-\ifthenelse {\boolean{paper}}
+\section{Failure inhibition and conjunction}
-{
+
-paper
+\subsection{Inhibition}
-}
+Failure inhibition is where a failure can only become active given a pre-condition.
-{
+A component suseptible to a given temperature range 
-chapter
+making a failure mode a possibility is an inhibit condition.
-}
+
+For instance in electronics, a semi-conductor may begin to
+fail at an eleveted temperature range.
+Or in mechanical engineering a rubber seal may become brittle and leak
+at low temperatures.
+
+What we have is an inhibit condition, in this case the temperature 
+being in range makes the particular failure mode impossible.
+
+The component $K$ in the DAG example (see section \ref{dagexample}), has 
+a failure mode $d$ that is only present at an elevated temperature 
+range, and has been considered as a static failure possibility in that model.
+
+Where dynamic modelling of environmental conditions is required, inhibit gates
+need be used in the model.
+
+
+Inhibit conditions are part of the FTA methodology.%\cite{nucfta}[IV-9].
+To ensure that FMMD can produce FTA models, support for inhibit gates has been included.
+Both the NASA \cite{nasafta} and the U.S. Nuclear regulatory commission\cite{nucfta}[IV-9]  use
+a hexagon as a symbol for an inhibit gate in thier FTA documentation. That notation has been carried forward into FMMD.
+%[regular polygon,regular polygon sides=7]
+
+% \begin{figure}
+% \centering
+% \begin{tikzpicture}[shorten >=1pt,->,draw=black!50, node distance=\layersep]
+%     \tikzstyle{every pin edge}=[<-,shorten <=1pt]
+%     \tikzstyle{fmmde}=[circle,fill=black!25,minimum size=17pt,inner sep=0pt]
+%     %\tikzstyle{fmmdi}=[rectangle,fill=black!25,minimum size=17pt,inner sep=0pt]
+%     \tikzstyle{fmmdi}=[regular polygon,regular polygon sides=6],fill=black!25,minimum size=17pt,inner sep=0pt]
+%     \tikzstyle{component}=[fmmde, fill=green!50];
+%     \tikzstyle{failure}=[fmmde, fill=red!50];
+%     \tikzstyle{symptom}=[fmmde, fill=blue!50];
+%     \tikzstyle{inhibit}=[fmmdi, fill=black!20];
+%     \tikzstyle{conjunction}=[fmmde, fill=red!20];
+%     \tikzstyle{annot} = [text width=4em, text centered]
+%
+% 	\node[component] (C-1) at (0,-2) {$C^0_1$};
+% 	\node[fmmdi] (I-1) at (\layersep,-2) {$ > 80\oc$};
+%        \path (C-1) edge (I-1);
+%        \node[failure] (f) at (\layersep*2,-2)  {$a$}; 
+%        \path (I-1) edge (f);
+%
+% \end{tikzpicture}
+% % End of code
+% \caption{DAG representing inhibit condition ($ > 80\oc$) on failure mode $a$}
+% \label{fig:daginhibit}
+%\end{figure}
+
+We can also use a failure mode as an inhibit condition.
+For instance if we have a failure mode $C^0_{1a}$ that when active 
+makes failure mode $C^0_{1b}$ possible we can link 
+them using an inhibit gate as shown in figure \ref{fig:inhibitf2}.
+
+
+
+ \begin{figure}
+ \centering
+ \begin{tikzpicture}[shorten >=1pt,->,draw=black!50, node distance=\layersep]
+     \tikzstyle{every pin edge}=[<-,shorten <=1pt]
+     \tikzstyle{fmmde}=[circle,fill=black!25,minimum size=17pt,inner sep=0pt]
+     %\tikzstyle{fmmdi}=[rectangle,fill=black!25,minimum size=17pt,inner sep=0pt]
+     \tikzstyle{fmmdi}=[regular polygon,regular polygon sides=6],fill=black!25,minimum size=17pt,inner sep=0pt]
+     \tikzstyle{component}=[fmmde, fill=green!50];
+     \tikzstyle{failure}=[fmmde, fill=red!50];
+     \tikzstyle{symptom}=[fmmde, fill=blue!50];
+     \tikzstyle{inhibit}=[fmmdi, fill=blue!20];
+     \tikzstyle{conjunction}=[fmmde, fill=red!20];
+     \tikzstyle{annot} = [text width=4em, text centered]
+
+ 	\node[component] (C-1) at (0,-2) {$C^0_1$};
+ 	\node[component] (C-2) at (0,-5) {$C^0_1$};
+
+        \node[failure] (c1a) at (\layersep*2,-2)  {$a$}; 
+
+        \node[failure] (c2a) at (\layersep*2,-5)  {$b$}; 
+        \node[failure] (c2b) at (\layersep*2,-4)  {$a$}; 
+
+	\path (C-2) edge (c2a);
+        \path (C-2) edge (c2b);
+
+ 	\node[inhibit] (I-1) at (\layersep,-2) {Inhibit};
+	\path (C-1) edge (I-1);
+        \path (c2b) edge (I-1);
+
+        \path (I-1) edge (c1a);
+
+
+ \end{tikzpicture}
+ % End of code
+ \caption{DAG representing inhibit of failure mode $C_{2b}$ on another failure mode $C_{1a}$}
+ \label{fig:daginhibit2}
+\end{figure}
+
+
+
+
+
+\subsection{Conjunction}
+
+Failure conjunction is simply considering, at the {\fg} analysis stage
+the possibility of two components failing within the same timeframe.
+We could for instance, looking at a fuel train to a burner/chemical~reactor;
+consider both shutoff valves failing at the same time.
+
+For high levels of safety or reliability, in critical sub-systems, all possible double
+simultaneous failures may have to be considered \cite{en298}. 
+
+
+ \begin{figure}
+ \centering
+ \begin{tikzpicture}[shorten >=1pt,->,draw=black!50, node distance=\layersep]
+     \tikzstyle{every pin edge}=[<-,shorten <=1pt]
+     \tikzstyle{fmmde}=[circle,fill=black!25,minimum size=17pt,inner sep=0pt]
+     %\tikzstyle{fmmdi}=[rectangle,fill=black!25,minimum size=17pt,inner sep=0pt]
+     \tikzstyle{fmmdi}=[regular polygon,regular polygon sides=6],fill=black!25,minimum size=17pt,inner sep=0pt]
+     \tikzstyle{component}=[fmmde, fill=green!50];
+     \tikzstyle{failure}=[fmmde, fill=red!50];
+     \tikzstyle{symptom}=[fmmde, fill=blue!50];
+     \tikzstyle{inhibit}=[fmmdi, fill=grey!40];
+     \tikzstyle{conjunction}=[fmmde, fill=red!40];
+     \tikzstyle{annot} = [text width=4em, text centered]
+
+ 	\node[component] (C-1) at (0,-2) {$C^0_1$};
+
+        \node[failure] (C-1a) at (\layersep,-1) {a}; 	
+        \node[failure] (C-1b) at (\layersep,-2) {b}; 	
+        \node[failure] (C-1c) at (\layersep,-3) {c}; 	
+	
+     \path (C-1) edge (C-1a);
+     \path (C-1) edge (C-1b);
+     \path (C-1) edge (C-1c);
+
+	\node[conjunction, right of=C-1b]  (CJ) {$\&$};
+
+     \path (C-1a) edge (CJ);
+     \path (C-1b) edge (CJ);
+     \path (C-1c) edge (CJ);
+
+ \end{tikzpicture}
+ % End of code
+ \caption{DAG representing conjunction condition on failure modes $a \wedge b \wedge c$}
+ \label{fig:dagconjunction}
+\end{figure}
+
+\subsection{Failure Mode Conjuction Conditions represented in the DAG}
+
+White filled node with an \& in it.
+
+\subsection{Inhibit Conditions represented in the DAG}
+
+Inhibit node type. Octagon (to follow example from FTA).
+
+a -> OCT
+
+inhibitcond--
+
+
+%\section{Current Static Failure Mode Methodologies}
+%\ifthenelse {\boolean{paper}}
+%{
+%paper
+%}
+%{
+%chapter
+%}
 
 
 

fmmd_data_model/paper.tex

@@ -7,6 +7,7 @@
 \input{../style}
 \usepackage{ifthen}
 \usepackage{lastpage}
+\usetikzlibrary{shapes,snakes}
 
 \newboolean{paper}
 \setboolean{paper}{true} % boolvar=true or false

fmmd_design_aide/fmmd_design_aide.tex

@@ -77,7 +77,7 @@ The `undetectable' failure modes undertsandably, are the most worrying for the s
 EN61058, the statistically based European Norm, using ratios
 of detected and undetected system failure modes to
 classify the sytems safety levels and describes sub-clasifications
-for detected and undetected failure modes \cite{EN61508}.
+for detected and undetected failure modes \cite{en61508}.
 
 %It is these that are, generally the ones that stand out as single 
 %failure modes. 

thesis.tex

@@ -3,6 +3,7 @@
 \usepackage{graphicx}
 \usepackage{fancyhdr}
 \usepackage{tikz} 
+\usetikzlibrary{shapes,snakes}
 \usepackage{subfigure}
 \usepackage{amsfonts,amsmath,amsthm}
 \usepackage{algorithm}