diff --git a/fmmd_concept/fmmd_concept.tex b/fmmd_concept/fmmd_concept.tex
index 44a2ebe..ffb20e7 100644
--- a/fmmd_concept/fmmd_concept.tex
+++ b/fmmd_concept/fmmd_concept.tex
@@ -321,7 +321,7 @@ In practise, this following to all components on the signal path, will not be do
 Typically simpler scenarios will be used where the effect of
 the component failure will be considered in isolation and then applied to the signal path.
 
-\paragraph{Reasoning distance - complexity and reach-ability.}
+\paragraph{Concept of `reasoning distance' - complexity and reach-ability.}
 Tracing a component level failure up to a top level event, without the rigour accompanying state explosion, involves
 working heuristically. A base component failure will typically 
 be conceptually removed by several stages from a top level event.
@@ -1135,9 +1135,9 @@ failure modes and environmental factors.
 
 
 
-\subsection{Justification of wishlist}
+\subsection{Justification of desirable requirements}
 
-By applying the methodology in section \ref{fmmdproc}, the wishlist can
+By applying the methodology in section \ref{fmmdproc}, the desirable requirements can
 now be evaluated for the proposed FMMD methodology.
 
 \subsubsection{All component failure modes must be considered in the model.}
@@ -1335,6 +1335,14 @@ The terms used in FMMD and the UML data model are further refined in
 chapter \ref{defs}.
 }
 
+\section{The {\fg}: discussion and guidelines}
+
+Talk about reasons why {\fgs} should be small but complete enough
+to perform a given function.
+If they become too big we have a state explosion problem.
+If too small they become meaningless. PD is a good example of this
+appropriate for most situations, but perhaps getting confusing if applied to a non inverting op-amp gain stage.
+
 \section{Conclusion}
 
 This