When Software Goes Wrong - The Cambrian Line Incident

In this fourth podcast about the impact of software failures on railway asset safety, I talk with Dr Emma Taylor about the causes of the Cambrian Line Incident. Failures both of the software system and of the processes during development, testing and implementation.

Emma also talks about the industry's response to recommendation 3 in the RAIB report on the incident.

Listen to the podcast

Topics in this episode include:

• Emma describes the Cambrian Line Incident [1:04]
• Emma explains how the European Rail Traffic Management System works and what went wrong to cause this incident [1:52]
• Emma talks about how this failure could have been foreseen, some of the factors that led to it happening, and how it affected the signalling system [3:39]
• Emma talks about the RAIB recommendation about safety learning and what didn't happen that should. Particularly the need to have historic system data saved to determine what actually went wrong [5:41]
• Emma talks about the importance of reporting system faults, however minor they may seem. About how different complex software-based systems need to be integrated, and new functionality needs to be tested for its impact on existing applications [7:30]
• Emma gives her personal view on how you can determine whether the software you are using is complex or not, and reiterates the importance of recording software failures [8:47]
• Emma talks about how we need to change our way of thinking about systems that include a software component. And that includes many people and processes as well as the physical components of a system [10:10]
• …Emma suggests that compliance with standards and the usual assessment processes may not always give a comprehensive check of all the things that might go wrong [11:45]
• …Emma talks about the need for us all to have to learn a bit of a new language to explain how things are supposed to work and what happens when something does go wrong [12:20]
• Emma describes what the industry is doing to address these issues [13:15]
• Close [14:50]

Resources mentioned in this episode:

• Loss of safety critical signalling data on the Cambrian Coast line, 20 October 2017
• The digital bits of a system, podcast episode 6

Other related resources:

• LHSBR Infrastructure Asset Integrity section
• LHSBR Rolling Stock Asset Integrity section.