201210 – Griffiths – Software Reliability – An Oxymoron?

Rarely a week goes by without a major software failure featuring prominently in the news. Some problems, such as the reported “computer glitches” with Virgin Blue’s check-in software in 2010, merely result in financial loss. Others, such as the Queensland Health payroll debacle, in 2011, contribute to the downfall of governments. And of course there have also been cases where software unreliability has contributed to unavailability of critical public infrastructure, and in some cases, loss of life.

But how vulnerable is the rail industry to software unreliability, and what’s the real likelihood that software problems could actually stop the trains (or even crash the trains)?

This paper will provide a brief survey of the extent to which modern railways depend on correct software operation. We will show that this dependency extends from customer facing applications such as web-based journey planners and fare sales and collection systems, through to critical service delivery applications such as routing trains, scheduling essential maintenance, and responding to emergencies.