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@ -249,9 +249,9 @@ take a given component $C$ and return its set of failure modes $F$.
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$$ FM : C \mapsto F $$
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\begin{definition}
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We can define a set $U$ which is a set of sets of failure modes, where
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We can define a set $\mathcal{U}$ which is a set of sets of failure modes, where
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the component failure modes in each of its members are unitary~state.
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Thus if the failure modes of $F$ are unitary~state, we can say $F \in U$.
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Thus if the failure modes of $F$ are unitary~state, we can say $F \in \mathcal{U}$.
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\end{definition}
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\section{Component failure modes:\\ Unitary State example}
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@ -271,7 +271,7 @@ Thus because both fault modes cannot be active at the same time, the intersectio
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$$ R_{SHORTED} \cap R_{OPEN} = \emptyset $$
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therefore
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$$ FM(R) \in U $$
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$$ FM(R) \in \mathcal{U} $$
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We can make this a general case by taking a set $F$ (where $f_1, f_2 \in F$) representing a collection
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@ -283,7 +283,7 @@ We can say that if any pair of fault modes is active at the same time, then the
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unitary state:
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we state this formally
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\begin{equation}
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\forall f_1,f_2 \in F \dot ( f_1 \neq f_2 \wedge \mathcal{ACTIVE}({f_1}) \wedge \mathcal{ACTIVE}({f_2}) ) \implies F \not\in U
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\forall f_1,f_2 \in F \dot ( f_1 \neq f_2 \wedge \mathcal{ACTIVE}({f_1}) \wedge \mathcal{ACTIVE}({f_2}) ) \implies F \not\in \mathcal{U}
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\end{equation}
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@ -293,7 +293,7 @@ we state this formally
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% \end{equation}
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That is to say that it is impossible that any pair of failure modes can be active at the same time
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for the failure mode set $F$ to exist in the family of sets $U$.
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for the failure mode set $F$ to exist in the family of sets $\mathcal{U}$.
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Note where that are more than two failure~modes,
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by banning any pairs from being active at the same time
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we have banned larger combinations as well.
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@ -382,8 +382,8 @@ for each component in the functional group under analysis.
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For example: were we to have a simple functional group with two components R and T, of which
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$$FM(R) = \{R_o, R_s\}$$ and $$FM(T) = \{T_o, T_s, T_h\}$$.
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This means that a functional~group $FG=\{R,T\}$ will have a component failure modes set % $FM_{cfg} $
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of $FM_{cfg} = \{R_o, R_s, T_o, T_s, T_h\}$
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This means that a functional~group $FG=\{R,T\}$ will have a component failure modes set
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of $FG_{cfg} = \{R_o, R_s, T_o, T_s, T_h\}$
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For a cardinality constrained powerset of 2, because there are 5 error modes ( $|{FG_{cfg}}|=5$),
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applying equation \ref{eqn:ccps} gives :-
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@ -432,9 +432,12 @@ where :
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that are members of the functional group $FG$
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i.e. $ \forall j \in J | C_j \in FG $
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\item Let $|{C}_{j}|$
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indicate the number of mutually exclusive fault modes each component has
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\item Let $SU$ be a set of unitary state failure modes from the functional group
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nder analysis $SU = FM(FG)$
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indicate the number of mutually exclusive fault modes of each component
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\item Let $FG_{cfg}$ be the collection of all failure modes
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from all the components in the functional group.
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\item Let $SU$ be a set of failure modes from the functional group,
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where all contributing components $C_j$
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are guaranteed to be `unitary state' i.e. $(SU = FG_{cfg}) \wedge (\forall j \in J | C_j \in \mathcal{U}) $
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\end{itemize}
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%}
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