hieracrhy of FMMD being described

presentations/fmea/fmea_pres.tex

@@ -454,11 +454,13 @@ judged to be in critical sections of the product.
 
 
 The FMMD methodology breaks the analysis down into small stages,
-by making the analyst choose functional groups of components, which are then when analysed.
+by making the analyst choose functional groups of components, to which FMEA is applied.
 When analysed, we will have a set of symptoms of failure for the functional group.
 We can then create a derived~component,
 to represent the functional group.
 We can use derived components to form `higher~level' functional groups.
+This creates an analysis hierarchy.
+
 This addresses the state explosion (where $O$ is order
 of complexity) $O=N^2$ inherent in equation~\ref{eqn:fmea_state_exp}.
 \end{frame}
@@ -466,7 +468,7 @@ of complexity) $O=N^2$ inherent in equation~\ref{eqn:fmea_state_exp}.
 \begin{frame}
 We can view the functional groups in FMMD as forming a hierarchy.
 If for the sake of example we consider each functional group to
-be three components, figure~\ref{fig:three_tree} shows
+be three components, the figure below shows
 how the levels work and converge to a top or system level.
 
 \begin{figure}