The Rail Safety and Standards Board Podcast

When Software Goes Wrong - A City Metro System

February 25, 2021 RSSB Season 1 Episode 14
The Rail Safety and Standards Board Podcast
When Software Goes Wrong - A City Metro System
Show Notes

In this fifth podcast about the impact of software failures on railway asset safety, Dr Emma Taylor talks about the causes behind an accident that happened during testing on a city metro system. Checks from the V-model that should have been applied during the development, testing and implementation of the complex, software-based system.

02:04 Using the V-model to verify and validate the integrity of safety-critical software systems.

03:10 The signalling failure incident and the major changes that were being tested.

04:43 The system definition step in the V-model—opinion on some assumptions made about the dependability of the core software.

05:16 Latent software faults.

05:50 Risk assessment, identifying hazards, and designing software systems to avoid them.

07:25 Some personal thoughts on why a data synchronization issue might have been missed.

08:15 The practical stages of software development, system requirements, and recording  design changes.

09:20 Failure of data copying between systems, and related process documentation.

10:22 The testing part of manufacture—verification and validation throughout the lifecycle.

11:38 The role of third-party, independent assessors in the development process.

 Resources mentioned in this episode:

The V-model on Geeks for Geeks.org: https://www.geeksforgeeks.org/software-engineering-sdlc-v-model/ 

The V-model for humans on Wikipedia: https://en.wikipedia.org/wiki/V-Model_(software_development) 

Loss of safety critical signalling data on the Cambrian Coast line, 20 October 2017: https://www.gov.uk/raib-reports/report-17-2019-loss-of-safety-critical-signalling-data-on-the-cambrian-coast-line 

The digital bits of a system podcast https://www.orr.gov.uk/guidance-compliance/rail/health-safety/strategy/rm3 

Other related resources:

LHSBR Infrastructure Asset Integrity section: https://www.rssb.co.uk/safety-and-health/leading-health-and-safety-on-britains-railway/infrastructure-asset-integrity 

LHSBR Rolling Stock Asset Integrity section: https://www.rssb.co.uk/safety-and-health/leading-health-and-safety-on-britains-railway/rolling-stock-asset-integrity