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Minor corrections --- send to J Howse.

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Robin Clark 2013-12-21 12:45:18 +00:00
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64
mybib.bib
View File

@ -388,9 +388,9 @@ doi={10.1109/RAMS.1996.500640},
ISSN={0149-144X},}
@ARTICLE{sfmea,
AUTHOR = "Chris Price, Neal Snooke",
AUTHOR = "Neal Snooke and Chris Price",
TITLE = "An Automated Software FMEA",
JOURNAL = "International System Safety conference singapore 2008",
JOURNAL = "International System Safety conference Singapore 2008",
YEAR = "2008"
}
@ -544,7 +544,7 @@ ISSN={2166-563X},}
% my bib file.
@ARTICLE{fmd91,
AUTHOR = "Reliability Analysis Center",
AUTHOR = "Reliability~Analysis~Center US~DOC",
TITLE = "Failure Mode/Mechanisms Distributions 1991",
JOURNAL = "United States Department of Commerce: F30602-91-C-0002",
YEAR = "1991"
@ -884,7 +884,7 @@ strength of materials, the causes of boiler explosions",
}
@BOOK{bfmea,
AUTHOR = "Robin E McDermot et all",
AUTHOR = "Robin McDermot",
TITLE = "The Basics of FMEA ISBN: 0-527-76320-9",
PUBLISHER = "Productivity",
YEAR = "1996"
@ -899,7 +899,7 @@ strength of materials, the causes of boiler explosions",
@BOOK{faa,
AUTHOR = "Federal Aviation Administration",
AUTHOR = "Federal~Aviation~Administration FAA",
TITLE = "System Safety Handbook",
PUBLISHER = "http://www.faa.gov/library/manuals/aviation/risk\_management/ss\_handbook/",
YEAR = "2008"
@ -973,14 +973,14 @@ ISSN={1530-2059},}
}
@PHDTHESIS{maikowski,
AUTHOR = "Leo M Maikowski",
TITLE = "Tolreranced Multiple Fault Diagnosis of Analog Circuits",
AUTHOR = "Leo~M Maikowski",
TITLE = "Tolereranced Multiple Fault Diagnosis of Analog Circuits",
SCHOOL = " Brighton University, School of Electrical Engineering",
YEAR = "1995"
}
@BOOK{cbds,
AUTHOR = "Chris~Price",
AUTHOR = "Chris Price",
TITLE = "Computer-Based Diagnostic Systems ISBN 3-540-76198-5",
PUBLISHER = "Springer Practitioner series",
YEAR = "1999"
@ -1013,14 +1013,14 @@ ISSN={1530-2059},}
@BOOK{f77,
AUTHOR = "A.~Balfour D.H.~Marwick",
AUTHOR = "A. Balfour and D.H. Marwick",
TITLE = "Programming in Standard Fortran 77 ISBN 0-435-77486-7",
PUBLISHER = "Heinemann Educational Books",
YEAR = "1979"
}
@BOOK{ctw,
AUTHOR = "Gregory~J.E.~Rawlins",
AUTHOR = "Gregory~J.E. Rawlins",
TITLE = "Compared to What ? An introduction to the analysis of algorithms ISBN 0-7167-8243-x",
PUBLISHER = "Computer Science Press",
YEAR = "1991"
@ -1029,14 +1029,14 @@ ISSN={1530-2059},}
@BOOK{alg,
AUTHOR = "Alan~Gibbons",
AUTHOR = "Alan Gibbons",
TITLE = "Algorithmic Graph Theory ISBN 0-521-28881-9",
PUBLISHER = "Cambridge University Press",
YEAR = "1985"
}
@BOOK{found,
AUTHOR = "Ian~Stewart, David~Tall",
AUTHOR = "Ian Stewart and David Tall",
TITLE = "The Foundations of Mathematics : ISBN 0-19-853165-6",
PUBLISHER = "Oxford University Press",
YEAR = "1977"
@ -1050,42 +1050,42 @@ ISSN={1530-2059},}
}
@BOOK{probstatcrash,
AUTHOR = " M~R~Spiegel, J~Schiller, A~Srinivasan",
AUTHOR = " M~R Spiegel and J Schiller and A Srinivasan",
TITLE = "Probability and Statistics Crash Course : SHCAUM'S : ISBN 0-07-138341-7",
PUBLISHER = "McGraw Hill",
YEAR = "2001"
}
@BOOK{probstat,
AUTHOR = " M~R~Spiegel",
AUTHOR = " M~R Spiegel",
TITLE = "Probability and Statistics Second edition : SHCAUM'S : ISBN 0-07-135004-7",
PUBLISHER = "Oxford University Press",
YEAR = "1988"
}
@BOOK{idmfssz,
AUTHOR = " D~C~Ince",
AUTHOR = " D~C Ince",
TITLE = " An Introduction to Discrete Mathematics, Formal System Specification and Z : Oxford : ISBN 0-19-853836-7",
PUBLISHER = "Oxford University Press",
YEAR = "1988"
}
@BOOK{rdh,
AUTHOR = "F~Langford-Smith",
AUTHOR = "F Langford-Smith",
TITLE = "Radio designers Handbook: Fourth Edition",
PUBLISHER = "ILIFFE",
YEAR = "1953"
}
@BOOK{wdycwopt,
AUTHOR = " Richard~P~Feynman",
AUTHOR = " Richard~P Feynman",
TITLE = " What do you care what other people think: Harper Collins : ISBN 0-586-21855-6",
PUBLISHER = " harpercollins",
YEAR = "1988"
}
@BOOK{joyofsets,
AUTHOR = " Keith~devlin",
AUTHOR = " Keith Devlin",
TITLE = " The Joy of Sets: 2nd edition: ISBN 978-0-387-94094-6",
PUBLISHER = " Springer",
YEAR = "1993"
@ -1133,61 +1133,61 @@ ISSN={0098-5589},}
address = {Greenwich, CT, USA},
}
@MISC{eulerviz,
author = "Peter~Rodgers, John~Howse, Andrew~Fish",
author = "Peter Rodgers and John~Howse and Andrew~Fish",
title = "Visualization of Euler Diagrams",
howpublished = "http://www.cmis.bton.ac.uk/research/vmg/papers/EulerViz.pdf",
year = "2005"
}
@MISC{eulerprop,
author = "Peter~Rodgers, John~Howse, Gem~Stapleton",
author = "Gem~Stapleton and Peter~Rodgers and John~Howse, ",
title = "Properties of Euler Diagrams",
howpublished = "http://www.cmis.bton.ac.uk/research/vmg/papers/",
year = "2007"
}
@MISC{en161,
author = "E N Standard",
author = "EN~Standard BSI",
title = "EN161:2007 Automatic shutoff valves for gas burners and gas appliances",
howpublished = "British standards Institution http://www.bsigroup.com/",
year = "2003"
}
@MISC{en298,
author = "E N Standard",
author = "EN~Standard BSI",
title = "EN298:2003 Gas Burner Controllers with forced draft",
howpublished = "British standards Institution http://www.bsigroup.com/",
year = "2003"
}
@MISC{en230,
author = "E N Standard",
author = "EN~Standard BSI",
title = "EN230:2005 Automatic burner control systems for oil burners",
howpublished = "British standards Institution http://www.bsigroup.com/",
year = "2005"
}
@MISC{en60730,
author = "E N Standard",
author = "EN~Standard BSI",
title = "EN60730: Automatic Electrical controls for household and similar use",
howpublished = "British standards Institution http://www.bsigroup.com/",
year = "1994"
}
@MISC{tisallenkey,
author="Texas Instruments",
author="Texas~Instruments TI",
title = "Analysis of the Sallen Key architecture: Application report",
howpublished = "Available from http://www.ti.com/lit/an/sloa024b/sloa024b.pdf",
year="2002"
}
@MISC{challenger,
author = "U.S. Presidential Commission",
author = "US~Presidential~Commission US-PCOM",
title = "Report of the SpaceShuttle Challanger Accident",
howpublished = "Available from http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers-commission/table-of-contents.html",
year = "1986"
}
@MISC{iec60812,
author = "IEC Standard",
author = "IEC~Standard BSI",
title = "IEC 60812:1985 Analysis Techniques for system reliability - Procedure for failure mode and effects analysis (FMEA)",
howpublished = "British standards Institution http://www.bsigroup.com/",
year = "1985"
@ -1237,7 +1237,7 @@ OPTissn = {},
@Manual{tlp181,
title = {TLP 181 Datasheet},
key = {TOSHIBA Photocoupler GaAs Ired and Photo−Transistor},
author = {Toshiba inc.},
author = {Toshiba},
OPTorganization = {},
address = {http://www.toshiba.com/taec/components2/Datasheet\_Sync//206/4191.pdf},
OPTedition = {},
@ -1265,7 +1265,7 @@ OPTissn = {},
@Manual{pic18f25k80erratta,
title = {Datasheet Erratta: PIC18F66K80 Family Silicon Errata and Data Sheet Clarification DS805119D},
OPTkey = {},
author = {Microchip inc},
author = {Microchip},
OPTorganization = {},
address = {http://ww1.microchip.com/downloads/en/DeviceDoc/80519d.pdf},
OPTedition = {},
@ -1285,7 +1285,7 @@ OPTissn = {},
@Manual{pic18f2523,
title = {PIC18F2523 Datasheet},
OPTkey = {},
author = {Microchip inc},
author = {Microchip},
OPTorganization = {},
address = {http://ww1.microchip.com/downloads/en/DeviceDoc/39755c.pdf},
OPTedition = {},
@ -1404,9 +1404,9 @@ OPTissn = {},
@TechReport{eurothermtables,
author = {Eurotherm Ltd.},
author = {Eurotherm},
title = {Thermocouple Emf TABLES and PLATINUM 100 RESISTANCE THERMOMETER TABLES},
institution = {Eurotherm, UK},
institution = {Eurotherm Ltd, UK},
year = {1973},
OPTkey = {},
OPTtype = {},

85
submission_thesis/CH2_FMEA/copy.tex
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@ -1134,11 +1134,13 @@ must be made where appropriate.
An example of component tolerance considered for FMEA
is given in section~\ref{sec:resistortolerance}.
\section{FMEA in current usage: Five variants}
%\section{FMEA in current usage: Five variants}
\section{FMEA in current usage: Four variants}
\paragraph{Five main Variants of FMEA}
%\paragraph{Five main Variants of FMEA}
\paragraph{Four main Variants of FMEA}
\begin{itemize}
\item \textbf{PFMEA - Production} Emphasis on cost reduction and product improvement;
%\item \textbf{PFMEA - Production} Emphasis on cost reduction and product improvement;
\item \textbf{FMECA - Criticality} Emphasis on minimising the effect of critical systems failing; % Military/Space
\item \textbf{FMEDA - Statistical Safety} Statistical analysis giving Safety Integrity Levels;
\item \textbf{DFMEA - Design or Static/Theoretical} Approval of safety critical systems using FMEA and single or double failure prevention;% EN298/EN230/UL1998
@ -1147,39 +1149,41 @@ is given in section~\ref{sec:resistortolerance}.
\section{PFMEA - Production FMEA : 1940's to present}
\fmmdglossPFMEA
%
Production FMEA (or PFMEA), is FMEA used to prioritise, in terms of
cost, problems to be addressed in product production.
%
It generally focuses on known problems and using their
statistical frequency %they occur
and their cost to fix multiplied gives a Risk Priority Number (RPN)
for the germane component {\fm}.
%
Fixing problems with the highest RPN number
will return most cost benefit~\cite{bfmea}.
%
An example PFMEA report is presented in table~\ref{tbl:pfmeareport}.
% benign example of PFMEA in CARS - make something up.
\subsection{PFMEA Example}
\begin{table}[ht]
\label{tbl:pfmeareport}
\caption{FMEA Calculations} % title of Table
\centering % used for centering table
\begin{tabular}{|| l | l | c | c | l ||} \hline
\textbf{Failure Mode} & \textbf{P} & \textbf{Cost} & \textbf{Symptom} & \textbf{RPN} \\ \hline \hline
relay 1 n/c & $1*10^{-5}$ & 38.0 & indicators fail & 0.00038 \\ \hline
relay 2 n/c & $1*10^{-5}$ & 98.0 & doorlocks fail & 0.00098 \\ \hline
% rear end crash & $14.4*10^{-6}$ & 267,700 & fatal fire & 3.855 \\
% ruptured f.tank & & & & \\ \hline
\hline
\end{tabular}
\end{table}
% Viva Voce: Chris Price said that production FMEA was FMEA for the production process not
% FMEA applied a s a cost saving strategy for mass produced items.
% I disagree slightly, but am removing it as it is explicitly mentioned as a minor correction. 21DEC2013
%
% \section{PFMEA - Production FMEA : 1940's to present}
% \fmmdglossPFMEA
% %
% Production FMEA (or PFMEA), is FMEA used to prioritise, in terms of
% cost, problems to be addressed in product production.
% %
% It generally focuses on known problems and using their
% statistical frequency %they occur
% and their cost to fix multiplied gives a Risk Priority Number (RPN)
% for the germane component {\fm}.
% %
% Fixing problems with the highest RPN number
% will return most cost benefit~\cite{bfmea}.
% %
% An example PFMEA report is presented in table~\ref{tbl:pfmeareport}.
%
% % benign example of PFMEA in CARS - make something up.
% \subsection{PFMEA Example}
% \begin{table}[ht]
% \label{tbl:pfmeareport}
% \caption{FMEA Calculations} % title of Table
% \centering % used for centering table
% \begin{tabular}{|| l | l | c | c | l ||} \hline
% \textbf{Failure Mode} & \textbf{P} & \textbf{Cost} & \textbf{Symptom} & \textbf{RPN} \\ \hline \hline
% relay 1 n/c & $1*10^{-5}$ & 38.0 & indicators fail & 0.00038 \\ \hline
% relay 2 n/c & $1*10^{-5}$ & 98.0 & doorlocks fail & 0.00098 \\ \hline
% % rear end crash & $14.4*10^{-6}$ & 267,700 & fatal fire & 3.855 \\
% % ruptured f.tank & & & & \\ \hline
% \hline
% \end{tabular}
% \end{table}
\section{FMECA - Failure Modes Effects and Criticality Analysis}
@ -1231,10 +1235,15 @@ A history of the usage and development of FMECA may be found in~\cite{FMECAresea
\paragraph{FMECA - Statistical variables.}
%
FMECA extends PFMEA, but instead of cost, a criticality or
seriousness factor is ascribed to putative top level incidents.
%Viva Voce: remove
% FMECA extends PFMEA, but instead of cost, a criticality or
% seriousness factor is ascribed to putative top level incidents.
% FMECA has three probability factors for component failures, a system operational time and a severity factor.
FMECA refines FMEA, but instead of a simple top level failure as a result, a criticality or
seriousness factor is also ascribed. %ascribed to putative top level incidents.
FMECA has three probability factors for component failures, a system operational time and a severity factor.
\textbf{FMECA ${\lambda}_{p}$ value.}
This is the overall failure rate of a base component.
This will typically be the failure rate per million ($10^6$) or

5
submission_thesis/CH3_FMEA_criticism/copy.tex
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@ -406,7 +406,8 @@ utterly anachronistic in the distributed real time system environment.
A summary of deficiencies in current FMEA methodologies is listed below:
\begin{itemize}
%\item FMEA type methodologies were designed for simple electro-mechanical systems of the 1940's to 1960's,
\item State explosion - impossible to perform FMEA exhaustively, %rigorously
\item State explosion - %impossible
very difficult/time consuming to perform FMEA exhaustively, %rigorously
\item Difficult to re-use previous analysis work,
\item Very difficult to model simultaneous/multiple failures,
\item Software and hardware models are separate (if the software is modelled at all) meaning the software interface may not be correctly modelled,
@ -555,7 +556,7 @@ A wish list is presented, stating the features that should exist
in an improved FMEA methodology,
\begin{itemize}
\item Must be able to analyse hybrid software/hardware systems,
\item no state explosion (i.e. XFMEA is impractical),
\item avoid state explosion (i.e. XFMEA is impractical by hand~\cite{cbds}),
\item exhaustive checking at a modular level, %(total failure coverage within {\fgs} all interacting component and failure modes checked),
\item traceable reasoning inherent in system failure models,% to aid repeatability and checking,
\item re-usable i.e. it should be possible to re-use analysis,

48
submission_thesis/CH4_FMMD/copy.tex
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@ -661,6 +661,9 @@ from base component level to the top and vice versa.
\fmmdglossDC
\fmmdglossSYMPTOM
\section{Defining terms}
\paragraph{A discussion on the terms Parts, Components and Base Components.}
@ -690,6 +693,13 @@ as a separate building block for a circuit.
For FMMD each of these four op-amps
in the chip would be considered to be a separate {\bc}.
% CAN WE FIND SUPPORT FOR THIS IN LITERATURE???
\fmmdglossBC
%
The above definition of a part, needs further refinement, i.e. to be defined as % defining
@ -710,12 +720,19 @@ In fact any lowest level building block with published failure modes could be co
but this determination is the choice of the analyst, which may be influenced by the particular
standard~\cite{en298}~\cite{en61508} %~\cite{en230}
to which the system is being approved/analysed.
To summarise, the terms, part, component, module and sub-system may have subtly different
interpretations for different methodologies.
%
FMMD considers two types of components, these are:
\begin{itemize}
\item A {\bc} --- A starting or building block entity with given failure modes,
\item A {\dc} --- An entity determined from failure mode analysis.
\end{itemize}
%a lowest level of assembly `part' or an atomic entity, which ever is the smaller
%and component to mean either a part or a sub-assembly.
%Definitions used in FMMD are lisfuckup mode or not?????ted in table~\ref{tbl:fmmd_defs} and discussed below.
%% FIDDLINGING STEREO SUB_SYSTEM EXAMPLE, THE FIDDLINGING CHILDRENS SECTION
%%
\subsection{Definition of terms: sound system example.}
\label{sec:cdplayer}
@ -775,7 +792,9 @@ to illuminate the CD might contain a handful of components, and as such would ma
as one of the base level {\fgs}. It is a good candidate because
it performs a well defined function and it could be considered a design module.
\paragraph{Functional grouping to {\dc} process outline.}
\subsubsection{Functional grouping to {\dc} process outline.}
\label{fmmdguide}
%\paragraph{Functional grouping to {\dc} process outline.}
%In choosing the lowest level (base component) sub-systems we would look
%for the smallest `functional~groups' of components within a system.
%piss %can
@ -811,16 +830,24 @@ An outline of the FMMD process is itemised below:
\fmmdglossBC
%
The FMMD process is described using formal definitions and algorithms in section~\ref{sec:symptomabs}.
}
% 21DEC2013 What is this bracket doing ?}
%What components all have in common is that they can fail, and fail in a
% number of well defined ways.
\paragraph{Functional grouping determination.}
Determining which components to include in a {\fg} is a decision
made by the analyst. The analyst must look at the system schematics/design~documentation and identify
potential {\fgs}. This would typically involve recognising configurations
of components performing specific functions.
To choose appropriate {\fgs} involves a good understanding of the sub-system in hand and an initial top down
perspective. % of it.
\paragraph{Failure modes used for {\bcs}.}
For common {\bcs}
there is established literature for the failure modes for the system designer to consider
(often with accompanying statistical
failure rates)~\cite{mil1991,en298,fmd91}.
%
\fmmdglossBC
\fmmdglossDC
%
For instance, a simple resistor is generally considered
to fail in two ways, it can go open circuit or it can short.
@ -1100,7 +1127,7 @@ the failure causation logic can be followed and thus the DAG's derived (see figu
%
\paragraph{Traceability and quality of FMMD analysis.}
By having an analysis report report for each analysis stage, %i.e. {\fg} to {\dc},
By having an analysis report for each analysis stage, %i.e. {\fg} to {\dc},
we add traceability to the reasoning applied to the FMMD process.
%
Consider that traditional FMEA has one large reasoning stage, that of component failure mode
@ -1164,7 +1191,7 @@ Because {\fgs} may include components at varying levels
of $\abslev$, having it quickly available as an attribute
will be required in practical implementations
to order the tree, and assist in preventing recursion in the hierarchy (i.e. where
a {\fg} could erroneously include a component above its-self in the hierarchy).
a {\fg} could erroneously include a component above its~self in the hierarchy).
%
The abstraction level concept is formally defined in appendix~\ref{sec:abstractionlevel}.
@ -1188,7 +1215,7 @@ are naturally mutually exclusive.
%
This also applies to {\dcs} produced in the FMMD process.
%
In the FMMD process common symptoms are are collected, i.e no component failure modes may be %shared
In the FMMD process common symptoms are collected, i.e no component failure modes may be %shared
linked to more than one symptom and therefore the failure modes of a {\dc} are mutually exclusive.
%
Thus FMMD naturally produces {\dcs} with failure modes that are mutually exclusive.
@ -1208,7 +1235,8 @@ we can have a final stage where we consider the subjective or contextual effects
With traditional FMEA methodologies this decision (the contextual effects)
has to be made for each component {\fm} in the system.
\paragraph{State explosion problem of FMEA solved by FMMD.}
\paragraph{State explosion problem of FMEA mitigated by FMMD.}
%\paragraph{State explosion problem of FMEA solved by FMMD.}
%
Because FMMD considers failure modes within functional groups;
the traditional state explosion problem in FMEA--which lead to the ideal of XFMEA---disappears.

115
submission_thesis/CH5_Examples/copy.tex
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@ -84,6 +84,8 @@ output voltage above or equal to zero would be erroneous i.e. an `$AMP_{HIGH}$'
A threshold would be determined for an `$AMP_{LOW}$' failure symptom (i.e. the output voltage more negative than expected). % error given the expected input range.
%
%This configuration is interesting from methodology pers.
Following the guidelines for the FMMD process (see section~\ref{fmmdguide}), initially potential {\fgs} are identified.
%
There are two obvious ways in which this circuit can be modelled.
%
One is to do this in two stages, firstly by considering the gain resistors to be a potential divider
@ -321,8 +323,112 @@ this amplifier (see figure~\ref{fig:invdag1}).
%
Note that this allows failure symptoms to be traced back to causes, i.e.
to traverse from system level or top failure modes to base component failure modes.
%
For the one stage analysis, a DAG showing the failure mode behaviour
is presented in figure~\ref{fig:invdag11}.
%%%%% 12DEC 2012 UP to here in notes from AF email.
%
\begin{figure}[h+]
\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=30pt,inner sep=0pt]
\tikzstyle{component}=[fmmde, fill=green!50];
\tikzstyle{failure}=[fmmde, fill=red!50];
\tikzstyle{symptom}=[fmmde, fill=blue!50];
\tikzstyle{annot} = [text width=4em, text centered]
% Draw the input layer nodes
%\foreach \name / \y in {1,...,4}
% This is the same as writing \foreach \name / \y in {1/1,2/2,3/3,4/4}
% \node[component, pin=left:Input \#\y] (I-\name) at (0,-\y) {};
\node[component] (OPAMP) at (0,-1.8) {$OPAMP$};
\node[component] (R1) at (0,-6) {$R_1$};
\node[component] (R2) at (0,-7.6) {$R_2$};
%\node[component] (C-3) at (0,-5) {$C^0_3$};
%\node[component] (K-4) at (0,-8) {$K^0_4$};
%\node[component] (C-5) at (0,-10) {$C^0_5$};
%\node[component] (C-6) at (0,-12) {$C^0_6$};
%\node[component] (K-7) at (0,-15) {$K^0_7$};
% Draw the hidden layer nodes
%\foreach \name / \y in {1,...,5}
% \path[yshift=0.5cm]
\node[failure] (OPAMPLU) at (\layersep,-0) {l-up};
\node[failure] (OPAMPLD) at (\layersep,-1.2) {l-dn};
\node[failure] (OPAMPNP) at (\layersep,-2.5) {noop};
\node[failure] (OPAMPLS) at (\layersep,-3.8) {lowslew};
\node[failure] (R1SHORT) at (\layersep,-5.1) {$R1_{Sh}$};
\node[failure] (R1OPEN) at (\layersep,-6.4) {$R1_{Op}$};
\node[failure] (R2SHORT) at (\layersep,-7.7) {$R2_{Sh}$};
\node[failure] (R2OPEN) at (\layersep,-9.0) {$R2_{Op}$};
% Draw the output layer node
% % Connect every node in the input layer with every node in the
% % hidden layer.
% %\foreach \source in {1,...,4}
% % \foreach \dest in {1,...,5}
\path (OPAMP) edge (OPAMPLU);
\path (OPAMP) edge (OPAMPLD);
\path (OPAMP) edge (OPAMPNP);
\path (OPAMP) edge (OPAMPLS);
\path (R1) edge (R1SHORT);
\path (R1) edge (R1OPEN);
\path (R2) edge (R2SHORT);
\path (R2) edge (R2OPEN);
% Potential divider failure modes
%
%\node[symptom] (PDHIGH) at (\layersep*2,-5.8) {$IPD_{HIGH}$};
%\node[symptom] (PDLOW) at (\layersep*2,-8.1) {$IPD_{LOW}$};
%\path (R1OPEN) edge (PDLOW);
% \path (R2SHORT) edge (PDLOW);
%\path (R2OPEN) edge (PDHIGH);
% \path (R1SHORT) edge (PDHIGH);
\node[symptom] (AMPHIGH) at (\layersep*4.4,-3) {$AMP_{HIGH}$};
\node[symptom] (AMPLOW) at (\layersep*4.4,-5) {$AMP_{LOW}$};
\node[symptom] (AMPLP) at (\layersep*4.4,-7) {$LOWPASS$};
\path (R1OPEN) edge (AMPHIGH);
\path (R1SHORT) edge (AMPLOW);
\path (R2SHORT) edge (AMPHIGH);
\path (R2OPEN) edge (AMPLOW);
%\path (PDLOW) edge (AMPHIGH);
\path (OPAMPLU) edge (AMPHIGH);
%\path (PDHIGH) edge (AMPLOW);
\path (OPAMPNP) edge (AMPLOW);
\path (OPAMPLD) edge (AMPLOW);
\path (OPAMPLS) edge (AMPLP);
\end{tikzpicture}
% End of code
\caption{Full DAG representing failure modes and symptoms of the Inverting Op-amp Circuit analysed in one stage.}
\label{fig:invdag11}
\end{figure}
%
\clearpage
\subsection{Second Approach: Inverting OpAmp analysing with three components in one larger {\fg}}
@ -473,7 +579,7 @@ It could be at either polarity. % (i.e. the other way around R4 could be the neg
%
Here, even though R3 and R4 are used as a potential divider,
it could be either inverted or non-inverted according to the voltages on the inputs.
Therefore the resistors cannot modelled as a potential divider, but must be placed in the {\fg}
Therefore the resistors cannot be modelled as a potential divider, but must be placed in the {\fg}
with the OpAmp and analysed.
%This means we are either going to
%get a high or low reading if R3 or R4 fail.
@ -629,6 +735,9 @@ This FMMD analysis also revealed an undetectable failure mode, $DiffAMPIncorrec
The circuit in figure~\ref{fig:circuit2} shows a five pole low pass filter.
%
Using the FMMD guidelines~\ref{fmmdguide}, a top down view of the circuit is taken, and then groups of components
performing specific tasks are identified.
%
Starting at the input, there is a first order low pass filter buffered by an op-amp,
the output of this is passed to a Sallen~Key~\cite{aoe}[p.267]~\cite{electronicssysapproach}[p.288] second order low-pass filter.
%
@ -982,6 +1091,10 @@ hence a fault anywhere in the loop is likely to affect all stages.
%
However, this is not a problem for FMMD, as {\fgs} are readily identifiable.
%
%
Using the FMMD guidelines~\ref{fmmdguide}, a top down view of the circuit is taken, and then groups of components
performing specific tasks are identified.
%
%The signal path is circular (its a positive feedback circuit) and most failures would simply cause the output to stop oscillating.
%The top level failure modes for the FMMD hierarchy bear this out.
%However, FMMD is a bottom -up analysis methodology and we can therefore still identify

2
submission_thesis/CH6_Software_Examples/software.tex
View File

@ -97,7 +97,7 @@ What is potentially difficult with applying FMMD to a software function, is deci
its component failure modes %(in electronics the failure modes of its components)---and
and its symptoms of failure in a manner compatible with the FMMD process. %(the failure modes of a function taken as a {\dc}) are.
%
With electronic components, the literature to points to suitable sets of
With electronic components, the literature points to suitable sets of
{\fms}~\cite{fmd91}~\cite{mil1991}~\cite{en298}. %~\cite{en61508}~\cite{en298}.
%
With software only some library functions are well known and rigorously documented

3
submission_thesis/colophon/abstract.tex
View File

@ -147,7 +147,8 @@ the examples analysed and theoretical models are used to demonstrate this.
% End what has been achieved ---- all in 300ish word OK here we go.
%Conclusions are presented listing the
%and FMMD is compared with traditional HFMEA and SFMEA.
This thesis presents a methodology that solves the state explosion problems of FMEA;
This thesis presents a methodology that %solves
mitigates the state explosion problems of FMEA;
provides integrated hardware and software failure mode models;
facilitates multiple failure mode analysis;
encourages re-use of analysis work

4
submission_thesis/colophon/copy.tex
View File

@ -55,7 +55,7 @@ Further I thank her for encouraging me to apply for the PhD. %% PITY SHE DID NOT
I also wish to thank Alan Jones of Brighton College of Technology
for taking a chance on someone with no `A' levels and letting him
start an HND in software Engineering in 1986. That more than anything
changed my life and gave me fantasic opportunities.
changed my life and gave me fantastic opportunities.
%
\\
\\
@ -213,7 +213,7 @@ the examples analysed and theoretical models are used to demonstrate this.
% End what has been achieved ---- all in 300ish word OK here we go.
%Conclusions are presented listing the
%and FMMD is compared with traditional HFMEA and SFMEA.
This thesis presents a methodology that solves the state explosion problems of FMEA;
This thesis presents a methodology that mitigates the state explosion problems of FMEA;
provides integrated hardware and software failure mode models;
facilitates multiple failure mode analysis;
encourages re-use of analysis work