Tag: Regulation

Probabilistic Predictions

Uncertainty is the only certainty. Not a radical statement. As long as I live, dealing with uncertainty is inevitable. Unavoidable everywhere. I wouldn’t have it any other way, even if it can be uncomfortable.

Prominent Ancient Greeks may have travelled to Delphi for advice as to what the future may hold. There’re those three enigmatic witches who warn Macbeth of his fate. History and fiction are littered with references.

For me, I can pick-up a newspaper and look for a daily astrological prediction. One I like. I can flick around social media and see more prophecies than ever. Mostly gibberish. There are those convinced of their foresight.

Despite a cynical disposition towards the above, science can be applied to the world of uncertainty. Generally, the proposition is that an element of the past and present will be reproduced in the future. This is not absolute. However, human engineered systems tend to behave with a degree of predictability.

Empirical methods, where society collects data from the past and present, can be useful in trying to forecast what may happen next. The more deterministic the systems under study, the more useful acquired data can be. For these, forecasting challenges mount for the new, novel, or radically altered.

I’m writing this given the interest there is in probabilistic safety. There are figures that hit the headlines that are almost incompressible. If the rationale behind the numbers is not clear then incorrect assumptions result. Tiny numbers from 1 x 10-6 to 1 x 10-9 are quoted in the News (SI Units). What do they mean? Let’s start with simple probability.

If an occurrence is certain then a numerical value of “1” can be given to it.

Absolute certainty is a rare thing. I can say that the Sun will rise tomorrow, and most people will take that as a statement of certainty. Intriguingly there’s the most incredibly improbable case where the solar system is thrown into instability and the Sunrise isn’t as expected.

If an occurrence never happens then a numerical value of “0” can be given to it.

Absolute impossibility is only possible with absolute knowledge. So, again it’s rare. I can say that human time-travel, to and from the distant past, is only fiction to next discover that a way has been found.

Let’s say we live in a world where the probability of occurrences ranges from the 0.99999, with ever more “9s”, to a number as small as 1 x 10-30[1]. A quecto.

These extreme numbers are nice for physicists and astronomers to play with, but they are outside normal engineering practices. As yet, we do not have the means to operate at the level of these limits. Time will tell. Or I maybe wrong.

By the way, I used the word “occurrence” above to denote anything that can happen in an instant. When talking about undesirable happenings, that can mean an incident, accident, mishap, slip, failure, or error. Each of these has a definition. Often more than one.

Next. I’ll go back to the tiny numbers more commonly quoted.

POST: For extraordinary numbers we need look no further than the nimble electron. So far, the best measurement for the life of an electron suggests that one now will still be around in 66,000 yottayears (6.6 × 1028 yrs). That’s about 5-quintillion times the current age of our universe. 

[1] https://www.nist.gov/pml/owm/metric-si-prefixes

From Prescription to Performance-Based Regulation

One regulatory development that has stuck since the start of the new century is the idea that we need to transition from prescriptive requirements to performance-based requirements. It’s not too hard to understand where the motivation to change has come from but there are several strands to the path. Here’s three that come to mind.

For one, the intense dislike of overbearing governmental regulators who adopt an almost parental attitude towards industry. It’s true that safety regulatory bodies have a duty to serve the public interest. The difficulty arises in interpreting that brief. Not as police officers sometimes did, imagining everyone as a potential miscreant.

My experience as a regulator started at a time when traditional institutional approach was quite common. There was a respectful distance between the airworthiness surveyor or operations inspector and the aviation industry that they oversaw. I think, even the term “surveyor” was one inherited from the insurance industry at the birth of flying.

A wave of liberalisation swept into the 1980s. It was an anathema to those who started their careers as men from the Ministry. The idea that regulators should be in a partnership with industry to meet common goals was not easily accepted. Undoubtably a change was necessary and, naturally, easier for an up-and-coming generation.

The next move away from regulatory prescription came as its value declined. That is, not that there will not always be an element of prescription by matter of the written law. However, for detailed technical considerations it became less and less practical to say, this is the way it must be. The minute decision-makers were faced with the complexity of a microprocessor it become clear that it’s not effective to simply prescribe solutions.

Much of the changes that took place can be traced to the evolution of system safety assessment and the use of probabilistic methods in aviation. In mechanics, prescribing a safety guard for a chain drive is straightforward. For complex electronics saying when a flight system is safe enough requires a different approach. Regulators are now driven to set objective rather than dictate solutions.

My third point is a future looking one. Whatever the history and heritage of aeronautical innovation, it’s true that a “conservative” but rapid adoption of new technology continues to be a source of success. Great safety success as well as commercial success.

Hidden amongst the successes are products, and ways of working that don’t meet the grade. The joke goes something like this: “How can I make a fortune in aviation?” Answer: “Just start with a big one.” Implicit in this observation is a wiliness to innovate at risk. That means, amongst many things, having confidence, adaptability and not be so constrained as to be assured failure. An objective or performance-based approach to safety regulation opens opportunity to innovate more freely whilst still protecting the public interest in safety.

There’s no fixed destination for regulatory development.

Bad Smell

Where is the accountability?

My desk, that’s the one in the early 1990s, faced towards the London Gatwick airport approach. It was a good reminder of the business we were in at the time. Seeing aircraft land and take-off about 500 m from the sheet glass windows of our office block was the daily background. Being in a rugged hermetically sealed building aircraft noise wasn’t a great concern.

Little more than 300m from the building and looking in the same direction was, and still is, the Gatwick sewage works. Its structures were low rise, so it was often hidden behind the greenery. Every so often, a strong wind would blow from the northeast. When it did a distinct odor filled the air. Yes, you guessed it. The sweet smell of the sewerage works would permeate the air conditioning.

This odor was at its most notable in the metrological conditions called an inversion[1]. In fact, given the seasonal frequency of these weather conditions it could be said that Gatwick wasn’t the most sensible place to build a major airport. These occasional pongs were a bit of a joke. Along with the occasional smells of unburnt aviation fuel it was just life at the airport. Lingering odors didn’t stay for long. A day at most and the wind would change direction back to where it normally came from – the south west.

Airports and sewage works are not a good combination for the health of rivers and streams. Long ago, when Gatwick airport was built the tributaries of the River Mole[2] were diverted. The part of that river, the Gatwick stream going north to south, at the end of the runway, is an unattractive V-shaped gully. Not nice for nature at all. There was a track that ran parallel with the river. In the summer, I’d walk that track at a lunchtime as it was a way of getting to the airport’s south terminal.

In the news, Thames Water are being fined for dumping raw sewage in the River Mole[3]. The consequences of the UK’s water regulator[4] taking a relatively hands-off approach to managing water companies, since privatisation in the late 1980s, has come home to roost.

I must admit, I’m not the least bit surprised. So far, the dance of those who shrug their shoulders astonishing. Ministers, regulators, company chiefs are all pointing fingers at each other.

The sequence of events is mind blowing when looked at over several decades[5]. Chief executives attracting massive salaries. Companies being loaded up with debt. Generous payouts to shareholders. Investments in infrastructure not keeping pace.

Ofwat, the regulator talks with incredible complacency. Such weak regulators are no more than a piggy in the middle as the powerful forces of unethical commercial behaviour and disinterested government oversight combine. As millions of families struggle with the cost of living this kind of failure is intolerable. Where is the accountability?

[1] https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/temperature/temperature-inversion

[2] https://www.southeastriverstrust.org/river-mole/

[3] https://www.independent.co.uk/news/uk/crime/thames-water-sewage-spill-gatwick-airport-b2368707.html

[4] https://www.ofwat.gov.uk/

[5] https://www.bbc.com/news/business-66103356.amp