If you want to know where Crew Resource Management as a discipline started, then you need to read NASA Technical Memorandum 78482 or “A Simulator Study of the Interaction of Pilot Workload With Errors, Vigilance, and Decisions” by H.P. Ruffel Smith, the British borne physician and pilot. Before this study it was hours in the seat and line seniority that mattered when things went to hell. After it the aviation industry started to realise that crews rose or fell on the basis of how well they worked together, and that a good captain got the best out of his team. Today whether crews get it right, as they did on QF72, or terribly wrong, as they did on AF447, the lens that we view their performance through has been irrevocably shaped by the work of Russel Smith. From little seeds great oaks grow indeed.
Archives For Decision making
The law of unintended consequences
There are some significant consequences to the principal of reasonable practicability enshrined within the Australian WHS Act. The act is particularly problematic for risk based software assurance standards, where risk is used to determine the degree of effort that should be applied. In part one of this three part post I’ll be discussing the implications of the act for the process industries functional safety standard IEC 61508, in the second part I’ll look at aerospace and their software assurance standard DO-178C then finally I’ll try and piece together a software assurance strategy that is compliant with the Act. Continue Reading…
Ladies and gentlemen you need to leave, like leave your luggage!
This has been another moment of aircraft evacuation Zen.
The NTSB have released their final report on the Boeing 787 Dreamliner Li-Ion battery fires. The report makes interesting reading, but for me the most telling point is summarised in conclusion seven, which I quote below.
Conclusion 7. Boeing’s electrical power system safety assessment did not consider the most severe effects of a cell internal short circuit and include requirements to mitigate related risks, and the review of the assessment by Boeing authorized representatives and Federal Aviation Administration certification engineers did not reveal this deficiency.
NTSB/AIR-14/01 (p78 )
In other words Boeing got themselves into a position with their safety assessment where their ‘assumed worst case’ was much less worse case than the reality. This failure to imagine the worst ensured that when they aggressively weight optimised the battery design instead of thermally optimising it, the risks they were actually running were unwittingly so much higher.
The first principal is that you must not fool yourself, and that you are the easiest person to fool
Richard P. Feynman
I’m also thinking that the behaviour of Boeing is consistent with what McDermid et al, calls probative blindness. That is, the safety activities that were conducted were intended to comply with regulatory requirements rather than actually determine what hazards existed and their risk.
… there is a high level of corporate confidence in the safety of the [Nimrod aircraft]. However, the lack of structured evidence to support this confidence clearly requires rectifying, in order to meet forthcoming legislation and to achieve compliance.
Nimrod Safety Management Plan 2002 (1)
As the quote from the Nimrod program deftly illustrates, often (2) safety analyses are conducted simply to confirm what we already ‘know’ that the system is safe, non-probative if you will. In these circumstances the objective is compliance with the regulations rather than to generate evidence that our system is unsafe. In such circumstances doing more or better safety analysis is unlikely to prevent an accident because the evidence will not cause beliefs to change, belief it seems is a powerful thing.
The Boeing battery saga also illustrates how much regulators like the FAA actually rely on the technical competence of those being regulated, and how fragile that regulatory relationship is when it comes to dealing with the safety of emerging technologies.
1. As quoted in Probative Blindness: How Safety Activity can fail to Update Beliefs about Safety, A J Rae*, J A McDermid, R D Alexander, M Nicholson (IET SSCS Conference 2014).
2. Actually in aerospace I’d assert that it’s normal practice to carry out hazard analyses simply to comply with a regulatory requirement. As far as the organisation commissioning them is concerned the results are going to tell them what they know already, that the system is safe.
Finding MH370 is going to be a bitch
The aircraft has gone down in an area which is the undersea equivalent of the eastern slopes of the Rockies, well before anyone mapped them. Add to that a search area of thousands of square kilometres in about an isolated a spot as you can imagine, a search zone interpolated from satellite pings and you can see that it’s going to be tough.
John Adams has an interesting take on the bureaucratic approach to risk management in his post reducing zero risk.
The problem is that each decision to further reduce an already acceptably low risk is always defended as being ‘cheap’, but when you add up the increments it’s the death of a thousand cuts, because no one ever considers the aggregated opportunity cost of course.
This remorseless slide of our public and private institutions into a hysteria of risk aversion seems to me to be be due to an inherent societal psychosis that nations sharing the english common law tradition are prone to. At best we end up with pointless safety theatre, at worst we end up bankrupting our culture.