According to the Hierarchy of Controls – a framework that has long been used for minimising workplace hazards – engineering controls are inherently safer than administrative controls.
However, as consultant Neil Robinson explains ahead of the RISSB Rail Safety Conference, this is not always the case.
"There are three issues to consider when deciding whether a software-based engineering control, is preferable over an administrative procedure," said Neil.
"Firstly, technologies designed to improve safety don’t always do so unless they are suitably engineered for purpose, and in accordance with strict industry standards.
"In the rail industry, for example, there have been many proposals lately for using iPads, Android or Windows tablets to replace safety-related administrative controls. However, the operating systems in these tablets are not engineered to the standards required for safety-related systems, and the applications may not be either.
"Additionally, it is not uncommon for there to be vulnerabilities or bugs in the software that cause them to start behaving incorrectly, even if they previously worked fine."
The second issue is the human tendency to over-trust and over-rely on safety software. This can be an issue even when the engineered control is used as a supplement to administrative procedures.
"When people get given a tool that helps them do something, they end up relying on it and believing what is says," said Neil.
"When first introduced the tool can give rise to safety improvements but, over time, as reliance on the tool grows, safety can actually decline as a result."
This 'irony of automation' has already been seen in other sectors. Tesla's autopilot functionality, for example, has been linked to various road traffic accidents, after some users defied the manufacturer's instructions and removed their hands from the wheel.
Additionally, a driver was killed in Chicago when her GPS – using outdated maps – directed her over a demolished bridge. This is despite a disclaimer on her system that users need to take responsibility for their own driving decisions.
Thirdly, when using an engineering control, the operator is forced to hand over responsibility for their well-being to the engineer that developed the system.
"This is fine when the engineer involved is keenly aware of the safety implications of their work, but your average software engineer is probably not," said Neil.
Despite these considerations, Neil believes technology can and should be procured to elevate safety within the rail sector.
"The hierarchy of controls still holds a lot of truth. The important message here is that it is not a bullet-proof framework and operators still need to apply good practice when introducing new technology in a safety-related environment," he concluded.
Dr. Neil Robinson is a Consultant and Director of RGB Assurance. He has 25 years' experience in safety-critical systems, including senior management roles with suppliers, and engineering and management roles in system safety engineering.
Neil is a Fellow of the Institution of Engineers Australia, a Chartered Engineer, Chartered Information Technology Professional (in UK), and holds a PhD. He is an Adjunct Professor in the School of Information Technology and Electrical Engineering at The University of Queensland. Currently, he spends much of his time as Independent Safety Assessor for the Cross River Rail and ETCS projects in Brisbane.
Join Neil for more discussion on this topic at the RISSB Rail Safety Conference, held as a virtual event on 27-28 October 2020.
Also due to present are representatives from John Holland, Sydney Metro, the Rail Industry Safety & Standards Board and the Railway Association of Canada.