ref from sccs, bemoaning no common formal language

This commit is contained in:
Robin Clark 2010-10-17 14:38:34 +01:00
parent 50ebba9952
commit 891a29a836
2 changed files with 6 additions and 1 deletions

View File

@ -254,7 +254,7 @@ of the Safety Integrity Levels (SIL) of EN61508 \cite{en61508}.
\section{A wish list for a failure mode methodolgy}
\begin{itemize}
\item All component failure modes must be considered in the model.
\item It should be easy to integrate mechanical, electronic and software models.
\item It should be easy to integrate mechanical, electronic and software models \cite{sccs}[pp.287].
\item It should be re-usable, in that commonly used modules can be re-used in other designs/projects.
\item It should have a formal basis, that is to say, it should be able to produce mathematical proofs
for its results.

View File

@ -118,6 +118,11 @@ computing elements. A tragic example of the mechanical and electrical elements
interfacing to a computer is found in the THERAC25 x-ray dosage machine.
With no common notation to integrate the saftey analyis between the electrical/mechanical and computing
domains, synchronisation errors occurred that were in some cases fatal.
The interfacing between the hardware and software for the THERAC-25 was not considered
in the design phase.
Niel Story in the formal methods chapter of "safety critical computer systems"
describes the different formal languages suitable for hardward and software and
bemaons the fact that no single language is suitable for for such a broad range of tasks \cite{sccs}[pp. 287].
\paragraph{Requirements for a rigorous FMEA process}
It was determined that any process to apply