[SystemSafety] Difference between software reliability and astrology

[Derek M Jones]

All,

> The FAA knows full well that software isn't perfect but concedes that the
> actual failure rate is not knowable so the FTA is used to ensure that the
> hardware meets the requirements but assumes that the process required for
> software development i.e. as laid out in DO178 is adequate to contain the SW
> failure rates within an acceptable bound. However there is no numerical
> targets for software reliability.
...
> So in summary failures in software are considered separately from failures
> in hardware.

Mike make some interesting interesting points about the FAA.
But what do the vendors do with regard to software failures?

When a failure occurs, do the people at the sharp end have a box
to tick specifying that this was/might be a software failure?
Unless raw data is being collected, software failure rate will
appear to be zero.  Even worse, the information needed to estimate
a rate will not be available.

-- 
Derek M. Jones           Evidence-based software engineering
blog:https://shape-of-code.com