Morning edit, multi symptoms problem

still need to talk about this in the conclusion
because FMMD solves this by allowing symptoms to be traced back
to component failutres

mybib.bib

@@ -1,3 +1,11 @@
+@INPROCEEDINGS{probfmea_4338247,
+author={Grunske, Lars and Colvin, R. and Winter, K.},
+booktitle={Quantitative Evaluation of Systems, 2007. QEST 2007. Fourth International Conference on the}, title={Probabilistic Model-Checking Support for FMEA},
+year={Sept.},
+pages={119-128},
+keywords={fault diagnosis;formal verification;probability;system monitoring;effect analysis;failure mode;probabilistic fault injection;probabilistic model checking;Accidents;Australia;Cause effect analysis;Failure analysis;Hazards;Information analysis;Information technology;Probability;Risk analysis;Safety;Failure Mode;Probabilistic Model Checking;System Safety;and Effect Analysis},
+doi={10.1109/QEST.2007.18},}
+
 
 @article{parnas1991assessment,
   title={Assessment of safety-critical software in nuclear power plants.},

submission_thesis/CH2_FMEA/copy.tex

@@ -608,6 +608,20 @@ because we can usually find Mean Time to Failure (MTTF) statistics for commonly
 Also, used in the design phase of a project, FMEA is a useful tool
 for discovering potential  failure scenarios~\cite{1778436820050601}.
 %
+From a whole system perspective, we may find that {\bc} {\fms}
+may have more than one possible system event associated with them.
+Often there will be a clear one to one mapping, but 
+probabilities to failure (as used in FMECA)
+could mean one to many.% mapping.
+%
+We could represent a failure mode and its possible outcomes using a Markov chain~\cite{probfmea_4338247}.
+%
+Where multiple simultaneous\footnote{Multiple simultaneous failures are taken to mean failures that occur within the same detection period.} 
+failure modes are considered this complicates
+the statistical nature of the Markov chain, cause effect model.
+%
+What we in fact get is the merging of two Markov chains
+for our cause effect model.
 % Subject Object Wiki answers : Best Answer
 %It is not grammar or vocabulary. It is a philosophical reference.
 %The dichotomy is the surrounding view of self that we act out of. It is often learned with language and not taught [like the alphabet and numbers are taught] in early life through language and the forming of distinctions.
@@ -628,17 +642,28 @@ the subjective sense can we determine its meaning and/or severity.
 It is worth remembering that
 failure mode analysis performed on the leaks possible from the O ring on the space shuttle
 did not link this failure to the catastrophic failure of the spacecraft~\cite{challenger,sanjeev}.
+%
 This was not a failure in the objective reasoning, but more of the subjective, or the context in which the leak occurred.
 %
+What this means is that for an objectively calculated failure mode outcome, we may have
+more than one subjective outcome definition for it.
+
+\paragraph{Multiple Simultaneous Failure Modes}
+%
 FMEA is less useful for determining events for multiple 
-simultaneous\footnote{Multiple simultaneous failures are taken to mean failures that occur within the same detection period.} 
+simultaneous 
 failures. 
 %
 Work has been performed using component failure statistics to
 offer the more likely multiple failures~\cite{FMEAmultiple653556} for analysis.
 %
+We now compound the multiple symptoms from one {\bc} {\fm} possibility
+with the merging of Markov chains.
 %
-This is because with the additional complication of having to change between these two modes of thinking, it becomes more difficult to 
+So for multiple failures we have the objective criteria complicated, and the subjective
+adds another layer of complication.
+%
+Also with the additional complication of having to change between these two modes of thinking, it becomes more difficult to 
 get a balance between subjective and objective perspectives.
 
 %subjective/objective become more cluttered when there are multiple possibilities