DeMarco/Lister Reference

Ariane 5 reference in Waltzing with Bears: Managing Risk on Software Projects, by Tom De\Marco and Timothy Lister.

on p. 113, the Ariane 5 event is mentioned as an example of risk mis-management. Here's the quote:

"Keeping mum about a risk won't make it go away. The staff of the Ariane 5 project,(*), for example, never did articulate the risk that a compiler would do no boundary checking, and thus compromise the launch vehicle. It happened anyway and resulted the total failure of the launch."

(*) "Ariane 5 was the European Space Agency's satellite launch that blew up due to a software error in 1996."

Susan's comment is that my take on this is nit-picking and their point is still correct. But it's not right. The errors were systems engineering and development errors, not a software error.

The Ariane 5 is an excellent example of risk mis-management, but the risk centered on using an Ariane 4 software module in Ariane 5 (which had a different flight trajectory), and, from the Inquiry report, not testing even in simulation. But the software, as written for Ariane 4, was not in error.

Dennis also comments that Ariane 4 and 5 used Ada compilers, so the statement about compiler not doing boundary checking is wrong.