could this be the final edit

submission_thesis/CH2_FMEA/copy.tex

@@ -154,6 +154,7 @@ In practice, this part of the process is guided by %%% PRACTICE NOUN Practice ma
 the particular standard
 which is being conformed to. %we are seeking to conform.% to.
 %
+%
 Standards may differ in their definitions for the {\fms} of {\bcs}.
 The reasons for these differences are examined below using two example components. 
 %
@@ -182,6 +183,8 @@ The FMEA investigator needs to know what failure behaviour a component could exh
 %
 A large body of literature exists giving guidance for the determination of  component {\fms}.
 %
+An interesting discussion on semi-conductor failure modes may be found in~\cite{ehb}[Ch.44].
+%
 For this study FMD-91~\cite{fmd91} and the gas burner standard EN298~\cite{en298} are examined.
 %Some standards prescribe specific failure modes for generic component types.
 In EN298 failure modes for most generic component types are listed, or if not listed, 
@@ -1627,7 +1630,7 @@ These factors mean that re-use, review and checking of traditional analysis can
 Work has been performed to assist in incremental FMEA production by use of a software  tool
 which in conjunction with circuit simulation
 and a database of component failure modes (providing consistency in terminology)
-speeds up the FMEA process~\cite{incrementalfmea}.
+speeds up the FMEA process and aids re-use~\cite{incrementalfmea}.
 %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

submission_thesis/CH3_FMEA_criticism/copy.tex

@@ -102,6 +102,9 @@ the fundamental problem remains, that, with any changes
 to the component base in a system, it is very difficult to
 determine which FMEA test scenarios must be re-worked.
 %
+With component failure mode databases, in conjunction with circuit simulation, work has been performed to address
+this~\cite{incrementalfmea}.
+%
 It is common in safety critical systems to have repeated circuit topologies.
 %
 For instance there may be several signal input and output
@@ -308,7 +311,7 @@ For instance, an AVO-8 multi-meter circa 1970, uses only analogue electronics an
 using FMEA how component failures within it could affect readings.
 %
 A modern multi-meter will have a small dedicated micro-processor and sensing electronics, all on the same chip,
-with firmware to read the user controls, and display results. % on an LCD.
+with firmware to read the user controls and display results. % on an LCD.
 %
 For quality control, many safety critical processes require regular inspections
 and measurements of physical characteristics of materials and machinery.

submission_thesis/CH4_FMMD/copy.tex

@@ -59,7 +59,7 @@ All the failure modes of all the components within a {\fg} are collected.
 %
 %A flat set is a set containing just the failure modes and not sets of failure modes~\cite{joyofsets}[p.8].
 %
-Each component failure mode can considered as a `failure~scenario' or 'test~case'
+Each component failure mode can be considered as a `failure~scenario' or 'test~case'
 to be applied to the {\fg}.
 %
 Each of these failure modes, and optionally combinations of them, are
@@ -238,7 +238,7 @@ for it outputting a low voltage `LowPD'. % Andrew asked for this to be defined b
 %
 %\vbox{
 From table  \ref{tbl:pdfmea} it can be seen that the resistor 
-failures modes lead to some common symptoms of failure from the perspective of the {\fg}.
+failure modes lead to some common symptoms of failure from the perspective of the {\fg}.
 %YOU FIDDLINGING FITTAS, TELL ME TO USE THE TERM SYMPTOM AND THEN TELL ME TO FIDDLINGING REMOVE IT A YEAR LATER> FITTAS 
 %symptoms.
 %These common symptoms of failure are an important concept for FMMD.
@@ -409,7 +409,7 @@ These op-amp failure modes are represented on the DAG in figure~\ref{fig:op1dag}
 %}
 %\clearpage
 %\paragraph{Modelling the OP amp with the potential divider.}
-The op-amp and the {\dc} {\em PD} now % andrew heavily critised this sentence but it made sense to Chris and I
+The op-amp and the {\dc} {\em PD} are now % andrew heavily critised this sentence but it made sense to Chris and I
 formed into a {\fg} to model the failure mode behaviour of the non-inverting amplifier.
 \fmmdglossOPAMP
 %
@@ -934,21 +934,21 @@ as examples.
 
 \section{Fault Mode Analysis, top down or bottom up?}
 
-Traditional static fault analysis methods work from the top down.
+Traditional static fault analysis methods, such as FTA~\cite{nucfta,nasafta}  work from the top down.
 They identify faults that can occur in a system, and then work down
 to see how they could be caused. 
 %
-Some apply statistical techniques to
-determine the likelihood of component failures 
-causing specific system level errors. 
-%
-For example the FMEA variant FMECA, uses
-Bayes theorem~\cite{probstat}[p.170]~\cite{nucfta}[p.74] (the relation between a conditional probability and its reverse)
-and is  applied to specific failure modes in components and their probability of causing given system level errors.
-\fmmdglossFMECA
-Another top down methodology is to apply cost benefit analysis 
-to determine which faults are the highest priority to fix~\cite{bfmea}.
-%
+% Some apply statistical techniques to
+% determine the likelihood of component failures 
+% causing specific system level errors. 
+% %
+% For example the FMEA variant FMECA, uses
+% Bayes theorem~\cite{probstat}[p.170]~\cite{nucfta}[p.74] (the relation between a conditional probability and its reverse)
+% and is  applied to specific failure modes in components and their probability of causing given system level errors.
+% \fmmdglossFMECA
+% Another top down methodology is to apply cost benefit analysis 
+% to determine which faults are the highest priority to fix~\cite{bfmea}.
+% %
 %\fmmdglossFMEA
 \fmeagloss
 %
@@ -958,7 +958,6 @@ models of safety critical systems  from the bottom-up,
 starting where possible with known base~component failure~modes.
 %
 %
-%
 An advantage of working from the bottom up is that it can be ensured that
 all component failure modes have been considered. 
 %
@@ -1124,7 +1123,7 @@ in quality systems~\cite{iso9001}.
 Having analysis reports increases the traceability---or documented paper trail---aiding understanding 
 and maintainability for failure mode models.
 %
-Also a  detailed cause and effect model is useful for creating diagnostic schemas~\cite{dbamafta}.
+Also a  detailed cause and effect model is useful for creating diagnostic schemas~\cite{dbamafta,cbds}.
 
 
 
@@ -1189,8 +1188,8 @@ are naturally  mutually exclusive.
 %
 This also applies to {\dcs} produced in the FMMD process.
 %
-In the FMMD process symptoms are are collected, i.e no component failure modes may be shared
-by a symptom within a {\fg}, and therefore the failure modes of a {\dc} are mutually exclusive.
+In the FMMD process common symptoms are 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.
 %
@@ -1254,7 +1253,7 @@ described in greater detail in section~\ref{sec:determine_fms}).
 % %
 The FMMD model can also be used 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}
+traditional FMEA, FMECA~\cite{safeware}[p.344], FMEDA~\cite{scsh}, diagnostics schemas~\cite{cbds,dbamafta}
 and other failure mode analysis methodologies.
 %
 \fmmdglossFTA

submission_thesis/CH5_Examples/copy.tex

@@ -86,10 +86,10 @@ A threshold would be determined for an `$AMP_{LOW}$' failure symptom (i.e. the o
 %This configuration is interesting from methodology pers.
 There are two obvious ways in which this circuit can be modelled.
 %
-One is to do this in two stages, by considering the gain resistors to be a potential divider
+One is to do this in two stages, firstly by considering the gain resistors to be a potential divider
 and then combining it with the OPAMP failure mode model.
 %
-The second is to place all three components in one {\fg}.
+Secondly to place all three components in one {\fg}.
 Both approaches are followed in the next two sub-sections.
 %
 \clearpage
@@ -821,7 +821,7 @@ results re-used for the next stage of analysis (see figure~\ref{fig:circuit2002_
 
 A derived component is created to represent the Sallen Key low pass filter, called $SKLP$:
 %
-$$ fm ( SKLP ) = \{ SKLPHigh,  SKLPLow, SKLPIncorrect, SKLPnosignal . \} $$
+$$ fm ( SKLP ) = \{ SKLPHigh,  SKLPLow, SKLPIncorrect, SKLPnosignal  \} . $$
 %
 %
 \clearpage
@@ -1269,7 +1269,7 @@ having 24 failure modes to consider against each of the other seven {\dcs}.
 A finer grained approach produces more potentially re-usable {\dcs} and 
 involved several stages with an overall lower reasoning distance.
 %
-The lower reasoning distances, or complexity comparison figures are given in the metrics chapter~\ref{sec:chap7}
+These reasoning distances, or complexity comparison figures are presented in the metrics chapter~\ref{sec:chap7}
 in section~\ref{sec:bubbaCC}.
 %
 This example demonstrates that the finer grained models 
@@ -1425,7 +1425,7 @@ This is an OpAmp in a signal buffer configuration
 and therefore simply has the failure modes of an Op-amp.
 %
 As it is performing one particular function
-it can be considered as a {\dc} a High Impedance Signal Buffer (HISB).
+it can be considered as a {\dc}, a High Impedance Signal Buffer (HISB).
 %
 This is analysed using FMMD in appendix~\ref{detail:HISB}.
 %
@@ -1436,7 +1436,7 @@ $$fm(HISB) = \{HIGH, LOW, NOOP, LOW_{SLEW} \}.$$
 %
 The integrator is implemented in analogue electronics, but the output from the D type flip flop is a digital signal.
 %
-A conversion stage is required to interface these stages.
+A conversion stage is required to interface these elements.
 %
 Digital level to analogue level conversion is performed by IC3 in conjunction with  a potential divider formed by R3,R4.
 %
@@ -1906,9 +1906,9 @@ As the Pt100 forms a potential divider with the \ohms{2k2}  load resistors,
 the upper and lower readings are calculated thus:
 %
 %
-$$ highreading = 5V.\frac{2k2+Pt100}{2k2+2k2+pt100} \; $$
+$$  sense+ = 5V.\frac{2k2+Pt100}{2k2+2k2+pt100} \; $$
 and
-$$ lowreading = 5V.\frac{2k2}{2k2+2k2+Pt100} \; .$$
+$$  sense- = 5V.\frac{2k2}{2k2+2k2+Pt100} \; .$$
 %
 So by defining an acceptable measurement/temperature range,
 and ensuring the 
@@ -1921,11 +1921,11 @@ resistors in this circuit have failed.
 To convert these to twelve bit ADC (\adctw)\footnote{An {\adctw} with a 5V Vref is assumed for this example. Raw ADC counts 
 would typically be used in software routines validating range/values in safety critical readings.} counts:
 %
-$$ highreading = 2^{12}.\frac{2k2+Pt100}{2k2+2k2+pt100}  $$
+$$  sense+ = 2^{12}.\frac{2k2+Pt100}{2k2+2k2+pt100}  $$
 %
 and 
 %
-$$ lowreading = 2^{12}.\frac{2k2}{2k2+2k2+Pt100} . $$
+$$  sense- = 2^{12}.\frac{2k2}{2k2+2k2+Pt100} . $$
 %
 %
 \begin{table}[ht]

submission_thesis/CH6_Software_Examples/software.tex

@@ -251,8 +251,23 @@ value from the external equipment is read.
 \section{Simple Software Example: Reading a \ft input into software}
 
 
-Consider a software function that reads a {\ft} input, and returns a value between 0 and 999 (i.e. per mil $\permil$)
+Consider a software function that reads a {\ft} input, 
+and returns a value between 0 and 999 (i.e. per mil $\permil$)
 representing the current detected; plus an additional error indication flag.
+
+The {\ft} input circuitry used in the example and its related software, 
+are accepted practise and in common use, 
+and therefore its failure mode behaviour is well known and understood. 
+%
+For this reason it is a good example to use for comparing the  results from FMMD analysis 
+with known failure mode behaviour from the field/direct experience of engineers. 
+%
+% The  failure model is then discussed and compared with heuristic knowledge of {\ft} inputs, 
+% circuitry and software. 
+% Conclusions are then presented listing the benefits and 
+% draw-backs of analysing the hardware/software hybrid system using FMMD, 
+% and FMMD is compared with traditional HFMEA and SFMEA.
+
 %
 From figure~\ref{fig:ftcontext} the {\ft} detection is via a \ohms{220} resistor and the voltage is read from an ADC into the software. 
 %
@@ -265,7 +280,7 @@ and $0.020A \times \ohms{220} = 4.4V$.
 %
 The acceptable voltage range\footnote{For the purpose of clarity  resistor tolerance has been ignored. 
 In a practical {\ft} reader  resistor tolerance would be factored into the limits, or 
-`deadbands' of $\approx \half mA$ at either end of the range would be implemented.} 
+`dead-bands' of $\approx \half mA$ at either end of the range would be implemented.} 
 is therefore 
 
 $$(V \ge  0.88) \wedge (V \le 4.4) \; .$$ 

submission_thesis/CH7_Evaluation/copy.tex

@@ -545,8 +545,9 @@ compared to the DFT algorithm.
 %\clearpage
 \section{Complexity Comparison applied to FMMD electronic circuits analysed in chapter~\ref{sec:chap5}.}
 
-All the FMMD examples in chapters \ref{sec:chap5} 
-and \ref{sec:chap6} showed a marked reduction in comparison 
+All the FMMD examples in chapter \ref{sec:chap5} 
+%and \ref{sec:chap6} 
+showed a marked reduction in comparison 
 complexity compared to  {\XFMEA}. % worst case figures. 
 %
 To calculate {\XFMEA} the comparison complexity equation~\ref{eqn:CC} is used.

submission_thesis/CH8_Conclusion/copy.tex

@@ -45,7 +45,7 @@ the HFMEA~\cite{sfmeaa,sfmea}. %, and while modular kept strictly to a bottom-up
 Using established concepts from contract programming~\cite{dbcbe}  FMMD was extended to analyse software,
 which facilitated a solution to the software/hardware interfacing problem~\cite{sfmeainterface}.
 %
-Two examples of mixed software and hardware systems were analysed as integrated FMMD models
+Two examples of hybrid software/hardware systems were analysed as integrated FMMD models
 as proof of concept. The first example in chapter~\ref{sec:chap6}, was
 presented to the System Safety IET conference in 2012~\cite{syssafe2012}.
 %
@@ -430,7 +430,7 @@ leading to idealised XFMEA requirements (see section~\ref{sec:reasoningdistance}
 Using FMMD only those modules in the hierarchy above the 
 component with the new failure mode need be re-visited.
 %
-The failure mode DAGs (see section~\ref{sec:chap4}) can be traced to determine exactly which
+The failure mode DAGs (see chapter~\ref{sec:chap4}) can be traced to determine exactly which
 {\fgs} exist in the hierarchy above the affected {\bcs}.
 %
 This means that with FMMD the re-work task can be precisely defined.
@@ -515,6 +515,15 @@ was therefore subjective.
 It was not known how the operators
 would have reacted and deficiencies in the Human Machine Interface (HMI) were not a factor in the failure analysis.
 
+\paragraph{Creation of a software FMMD tool.}
+%
+A software tool could be created with an extendible library/database of 
+base and derived components.
+%
+This tool could guide the user through the analysis and hierarchy construction processes
+and use the constraints and algorithms defined in appendix~\ref{sec:algorithmfmmd} and 
+the UML diagram developed (see figure\ref{fig:cfg})
+for verification of the process and models produced.
 
 \paragraph{Further Work: Objective and Subjective Reasoning in FMEA.}
 %

submission_thesis/colophon/copy.tex

@@ -147,7 +147,6 @@ Dated
 % Supervisors did not warn me this was required.
 % I found out by reading the OU ``how to get a PhD'' book in the bath, and then wading through the Brighton University
 % regulations where it is stated on page 14 of a 30+ page document filled with mostly n/a regulations to me.
-% Ho HUM. No wonder these shits have trouble working in the real world.
 %
 %
 
@@ -159,7 +158,7 @@ standards typically demand environmental stress, endurance and electro magnetic
 %
 Theoretical, or `static~testing' also a requirement. 
 %
-Failure Mode effects Analysis (FMEA) is a tool used for static testing.
+Failure Mode Effects Analysis (FMEA) is a tool used for static testing.
 FMEA is a bottom-up technique that aims to assess the effects 
 of all component failure modes in a system.
 %