morning edit

This commit is contained in:
Robin Clark 2010-08-02 08:45:03 +01:00
parent a5749d3588
commit b5f8a03743

View File

@ -165,12 +165,12 @@ $$ DTC(F) = TC $$
\ENDIF \ENDIF
\IF{Double fault checking} \IF{Double fault checking}
\STATE { let $f1,f2$ represet a component failure modes } \STATE { let $f1,f2$ represet a component failure modes, and $c$ a component in the functional group }
%\ENSURE { That all failure modes are represented in at least one test case } %\ENSURE { That all failure modes are represented in at least one test case }
\ENSURE { $ \forall f1,f2 \;where\; \not(f1,f2) \in c\;such\;that\; (f \in F)) \wedge (f \in \bigcup TC) $ } \ENSURE { $ \forall f1,f2 \;where\; (f1,f2) \not\in c\;such\;that\; (f \in F)) \wedge (f \in \bigcup TC) $ }
\COMMENT { This corresponds to checking that at least each possible double failure mode is considered at \COMMENT { This corresponds to checking that each possible double failure mode is considered
least once in the analysis; more rigorous cardinality constraint as a test case; more rigorous cardinality constraint
checks may be required for some safety standards. Not if both failure modes checks may be required for some safety standards. Note if both failure modes
in the check are sourced from the same component $c$ the test case is impossible in the check are sourced from the same component $c$ the test case is impossible
under unitary state failure mode conditions} under unitary state failure mode conditions}
\ENDIF \ENDIF
@ -312,6 +312,7 @@ $$ CDC: \mathcal{SP} \mapsto \mathcal{DC} $$
\STATE { $DC := DC \cap f_l$ } \COMMENT{ this is saying place $f_l$ into $DC$'s collection of failure modes} \STATE { $DC := DC \cap f_l$ } \COMMENT{ this is saying place $f_l$ into $DC$'s collection of failure modes}
\ENDFOR \ENDFOR
\ENSURE { $FM(DC) \neq \emptyset$ } \COMMENT{Ensure that DC has a known set of failure modes}
\RETURN DC \RETURN DC
%\hline %\hline
@ -322,7 +323,7 @@ Algorithm \ref{alg:sympabs55} is the final stage in the process. We now have a
derived~component $DC$, which has its own set of failure~modes. This can now be derived~component $DC$, which has its own set of failure~modes. This can now be
used in with other components (or derived~components) used in with other components (or derived~components)
to form functional~groups at higher levels of failure~mode~abstraction. to form functional~groups at higher levels of failure~mode~abstraction.
Hierarchies of fault abstraction can be built that can model an entire SYSTEM. %Hierarchies of fault abstraction can be built that can model an entire SYSTEM.
\section{Linking all five stages} \section{Linking all five stages}
@ -334,10 +335,10 @@ $$ \bowtie: \mathcal{FG} \mapsto \mathcal{DC} $$
\begin{algorithmic}[1] \begin{algorithmic}[1]
\STATE {F = FM (FG)} \COMMENT{ collect all the failure modes from the from the components in the functional~group } \STATE {F = FM (FG)} \COMMENT{ collect all component failure modes }%from the from the components in the functional~group }
\STATE {TC = DTC (F)} \COMMENT{ determine all test cases to apply to the functional group } \STATE {TC = DTC (F)} \COMMENT{ determine all test cases } %to apply to the functional group }
\STATE {R = ATC (TC)} \COMMENT{ analyse the test cases, for failure mode behaviour of the functional~group } \STATE {R = ATC (TC)} \COMMENT{ analyse the test cases }%, for failure mode behaviour of the functional~group }
\STATE {SP = FCS (R)} \COMMENT{ find common symptoms of failure for the functional group } \STATE {SP = FCS (R)} \COMMENT{ find common symptoms }%of failure for the functional group }
\STATE {DC = CDC (SP)} \COMMENT{ create a derived component } \STATE {DC = CDC (SP)} \COMMENT{ create a derived component }
\RETURN $DC$ \RETURN $DC$