The Chimera of Software Quality

by Les Hatton, in IEEE Computer, August 2007.

"Nobody knows how to produce a fault-free program. Nobody even knows how to prove it even supposing one we were magically provided. I teach my students that in their whole careers, they are unlikely ever to produce a fault-free program and if they did, they would never know it, they could never prove it and they could not systematically repeat it. It provides a usefully humble starting point.

[...] I've analysed enough failed systems in my time to know that there are two classic symptoms of a system on its way to the fairies. First, no independent audit is allowed and second, talking heads tell you everything is fine when the ultimate users tell you the opposite.

[...] The Linux kernel is now arguably the most reliable complex software application
humanity race has yet produced, with a mean time between failures reported in tens and in some cases, hundreds of years. Poetically, the development environment of Linux, which leverages the contributions of thousands of Web volunteers who give their spare time for the public good, breaks just about every rule which software process experts hold dear."