\section{Introduction}

Msc project Euler/Spider Diagram editor --- Euler/Spider Diagrams
could be used to model failure modes in components.
--- 2005 paper --- need for static analysis because of
high reliability of modern safety critical systems.

\section{Practical Experience: Safety Critical Product Approvals}

FMEA performed on selected areas perceived as critical
by test house.
Blanket measures, RAM ROM checks, EMC, electrical and environmental stress testing

\subsection{Practical limitations of testing for certification vs. rigorous approach}

State explosion problem considering a failure mode of a given component against
all other components in the system i.e. an exponential (2^N) order of processing resource rather than a ploynomial i.e. N^2.

Impossible to perform double simultaneous failure analysis (as demanded by EN298~\cite{en298}).

