John Ridgway studied physics at the University of Newcastle Upon Tyne and Sussex University before embarking upon a career in software engineering. As part of that career he worked for 28 years in the field of Intelligent Transport Systems (ITS), undertaking software quality management and systems safety engineering roles on behalf of his employer, Serco Transportation Systems. In particular, John provided design assurance for Serco’s development of the Stockholm Ring Road Central Technical System (CTS) for the Swedish National Roads Administration (SNRA), safety analysis and safety case development for Serco’s M42 Active Traffic Management (ATM) Computer Control System for the UK Highways Agency (HA), and safety analysis for the National Traffic Control Centre (NTCC) for the HA.
John is a regular contributor to the Safety Critical Systems Club (SCSC) Newsletter, in which he encourages fellow practitioners to share his interest in the deeper issues associated with the conceptual framework encapsulated by the terms ‘uncertainty’, ‘chance’ and ‘risk’. Although now retired, John recently received the honour of providing the after-banquet speech for the SCSC 2014 Annual Symposium.
Luke Muehlhauser: What is the nature of your expertise and interest in safety engineering?
John Ridgway: I am not an expert and I would not wish to pass myself off as one. I am, instead, a humble practitioner, and a retired one at that. Having been educated as a physicist, I started my career as a software engineer, rising eventually to a senior position within Serco Transportation Systems, UK, in which I was responsible for ensuring the establishment and implementation of processes designed to foster and demonstrate the integrity of computerised systems. The systems concerned (road traffic management systems) were not, initially, considered to be safety-related, and so lack of integrity in the delivered product was held to have little more than a commercial or political significance. However, following a change of safety policy within the procurement departments of the UK Highways Agency, I recognised that a change of culture would be required within my organisation, if it were to continue as an approved supplier.
If there is any legitimacy in my contributing to this forum, it is this: Even before safety had become an issue, I had always felt that the average practitioner’s track record in the management of risk would benefit greatly from taking a closer interest in (what some may deem to be) philosophical issues. Indeed, over the years, I became convinced that many of the factors that have hampered software engineering’s development into a mature engineering discipline (let’s say on a par with civil or mechanical engineering) have at their root, a failure to openly address such issues. I believe the same could also be said with regard to functional safety engineering. The heart of the problem lies in the conceptual framework encapsulated by the terms ‘uncertainty’, ‘chance’ and ‘risk’, all of which appear to be treated by practitioners as intuitive when, in fact, none of them are. This is not an academic concern, since failure to properly apprehend the deeper significance of this conceptual framework can, and does, lead practitioners towards errors of judgement. If I were to add to this the accusation that practitioners habitually fail to appreciate the extent to which their rationality is undermined by cognitive biases, then I feel there is more than enough justification for insisting that they pay more attention to what is going in the world of academia and research organisations, particularly in the fields of cognitive science, decision theory and, indeed, neuroscience. This, at least, became my working precept.