Walkie-Talkie “death ray” and risk identification

News media have been full of the tale of London’s Walkie-Talkie office block raising temperatures on the nearby highway to car melting levels.

The full story of how the architects and engineers created the problem has yet to be told. It is certainly the case that similar phenomena have been reported elsewhere. According to one news report, the Walkie-Talkie’s architect had worked on a Las Vegas hotel that caused similar problems back in September 2010.

More generally, an external hazard from a product’s optical properties is certainly something that has been noted in the past. It appears from this web page that domestic low-emissivity (low-E) glass was suspected of setting fire to adjacent buildings as long ago as 2007. I have not yet managed to find the Consumer Product Safety Commission report into low-E glass but I now know all about the hazards of snow globes.

The Walkie-Talkie phenomenon marks a signal failure in risk management and it will cost somebody to fix it. It is not yet clear whether this was a miscalculation of a known hazard or whether the hazard was simply neglected from the start.

Risk identification is the most fundamental part of risk management. If you have failed to identify a risk you are not in a position to control, mitigate or externalise it in advance. Risk identification is also the hardest part. In the case of the Walkie-Talkie, modern materials, construction methods and aesthetic tastes have conspired to create a phenomenon that was not, at least as an accidental feature, present in structures before this century. That means that risk identification is not a matter of running down a checklist of known hazards to see which apply. Novel and emergent risks are always the most difficult to identify, especially where they involve the impact of an artefact on its environment. This is a real, as Daniel Kahneman would put it, System 2 task. The standard checklist propels it back to the flawed System 1 level. As we know, even when we think we are applying a System 2 mindset, me may subconsciously be loafing in a subliminal System 1.

It is very difficult to spot when something has been missed out of a risk assessment, even in familiar scenarios. In a famous 1978 study by Fischhoff, Slovic and others, they showed to college students fault trees analysing potential causes of a car’s failure to start (this is 1978). Some of the fault trees had been “pruned”. One branch, representing say “battery charge”, had been removed. The subjects were very poor at spotting that a major, and well known, source of failure had been omitted from the analysis. Where failure modes are unfamiliar, it is even more difficult to identify the lacuna.

Even where failure modes are identified, if they are novel then they still present challenges in effective design and risk management. Henry Petroski, in Design Paradigms, his historical analysis of human error in structural engineering, shows how novel technologies present challenges for the development of new engineering methodologies. As he says:

There is no finite checklist of rules or questions that an engineer can apply and answer in order to declare that a design is perfect and absolutely safe, for such finality is incompatible with the whole process, practice and achievement of engineering. Not only must engineers preface any state-of-the-art analysis with what has variously been called engineering thinking and engineering judgment, they must always supplement the results of their analysis with thoughtful and considered interpretations of the results.

I think there are three principles that can help guard against an overly narrow vision. Firstly, involve as broad a selection of people as possible in hazard identification. Perhaps, diagonal slice the organisation. Do not put everybody in a room together where they can converge rapidly. This is probably a situation where some variant of the Delphi method can be justified.

Secondly, be aware that all assessments are provisional. Make design assumptions explicit. Collect data at every stage, especially on your assumptions. Compare the data with what you predicted would happen. Respond to any surprises by protecting the customer and investigating. Even if you’ve not yet melted a Jaguar, if the glass is looking a little more reflective than you thought it would be, take immediate action. Do not wait until you are in the Evening Standard. There is a reputation management side to this too.

Thirdly, as Petroski advocates, analysis of case studies and reflection on the lessons of history helps to develop broader horizons and develop a sense of humility. It seems nobody’s life is actually in danger from this “death ray” but the history of failures to identify risk leaves a more tangible record of mortality.


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