removed derived failure modes from UML class

diagrams and fixed some typos.

submission_thesis/CH4_FMMD/copy.tex

@@ -1021,7 +1021,7 @@ However, a  circuit designer would usually consider individual transistors and i
 as lowest level building blocks.
 %
 In fact any component with published failure modes could be considered to be a {\bc},
-but this determination is the choice of the analyst or the guidelines of the 
+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 we are approving/analysing a system.
 
 %a lowest level of assembly `part' or an atomic entity, which ever is the smaller
@@ -1074,7 +1074,7 @@ For instance in the CD~player example; if we start at the bottom, we are present
 a massive list of base~components, resistors, motors, user~switches, laser~diodes, all sorts! 
 Clearly, working from the bottom~up, we need to pick small
 collections of components that work together in some way.
-These are termed `{\fgs}'. 
+These collections are termed `{\fgs}'. 
 %
 For instance, the  circuitry that powers the laser diode
 to illuminate the CD might contain a handful of components, and as such would make a good candidate
@@ -1091,9 +1091,9 @@ When we have analysed the fault behaviour of a {\fg}, we can treat it as a `blac
 The {\fgs} fault behaviour will consist of a set of `symptoms' caused by combinations
 of its component failure modes.
 %
-We can thus make a new `component' derived from the symptoms found as a result of analysing the {\fg}.
+We can thus create a new `component' derived from analysing the {\fg} where
 %
-The symptoms of failure of the {\fg} are the failure modes of this new `derived component'.
+the symptoms of failure of the {\fg} are the failure modes of this new `{\dc}'.
 
 %We can now call our functional~group a sub-system or a derived~component. 
 %The goal here is to know how it will behave under fault conditions !