Risk

Off the Hook: Kangaroo Collision Case Appeal Allowed

Off the Hook: Kangaroo Collision Case Appeal Allowed

A little over a year ago, I wrote about a court case involving the owner of an aircraft claiming damages from an aerodrome operator after their aircraft collided with a kangaroo on landing. I was pretty proud of that post as I had exercised some newly developed court judgement reading skills. So, of course, the legal system would have to go an turn all that on its head and change its mind. It turns out that the aerodrome operator was not liable for the damage.

Let’s find out why and whether we agree with them…

Image credit: Altered photo by Scott Calleja

Wildlife Risk Management Series

Wildlife Risk Management Series

A long time ago I wrote a rather comprehensive series on wildlife hazard management within an ISO 31000 risk management framework. It was the launch series for the New Airport Insider website and quite a bit of work on my part - but I enjoyed it. So, I thought I would repackage it as a quick blog post with links to each article.

The $200K Kangaroo

The $200K Kangaroo

I’m not a big fan of safety tropes. They are often repeated without much thought and eventually this repetition becomes detached from the concept the trope is trying to convey. With many tropes, there are few non-trivial or non-catastrophic events that can reinforce the trope.

The saying on my mind today is “if you think safety is expensive, try having an accident”. The “accident” I often think about is something big, something catastrophic and something that happens to other people. I rarely uttered this trope because I, personally, didn’t feel the power of it.

Now, thanks to a court case in Australia, I feel the power has been returned to this saying. We know have a non-catastrophic event with quantifiable costs associated with the “safety” part and the “accident” part. Plus, I think nearly every airport safety professional out there can empathise with the operator in the case

Noun-based Regulation

The modern world is definitely in love with its noun-based activities. Each week, a paradigm-shifting approach to some human endeavour is announced with a title like value-based health care or outcome-based education. When I delve into the details, I am generally left either confused as to what they are selling or how they are different at all. Regulation is no different. Just plugging "based regulation" into Google yields, on the first page alone, principle-basedresults-basedperformance-basedoutcomes-based and output-based regulatory approaches.

BTII: Control-freak*

BTII: Control-freak*

As a follow-on to my first post on the Bow-Tie risk assessment method, I thought I'd concentrate on controls (or barriers or whatever else you would like to call them). This is, after all, where all the action happens. Risk controls are how we spend most of our time - they are the practical aspect of managing risk.

BTI: Dressing up for Risk Assessments

BTI: Dressing up for Risk Assessments

I've been doing a lot of pondering on the Bow-Tie method of risk assessment for a project at work. Bow-Tie is a tool used by many, especially in the oil & gas industry, to create a picture of risk surrounding a central event. It's got a few positives and a few negatives but these can be overcome if you understand the limitations of the model being used.

As Low As Reasonably Practicable

It's another staple of the risk management diet but while I believe this one to be a completely valid concept, I can't help to feel that its being served up underdone. This time I'm talking about ALARP - As Low As Reasonably Practicable. To define ALARP, at least how I do, would probably negate the need to write the rest of this post. So let's just say that ALARP is the point at which any further reduction in risk would require resources significantly greater than the magnitude in the benefit gained1.

It is often described graphically. Here are a few examples of the types of diagrams you may see helping to explain the concept:

The left diagram is the one I see the most although I am seeing, more and more, other representations including the other two. Rather than link any specific instances on the web, feel free to find such diagrams using Google Images.

So what are the problems that I see with most of these graphs? Thanks for asking...

The ALARP Region

In the left diagram, it is shown as an orange trapezoid and in the centre diagram, it is a line but in both cases the point of this area is to identify the level of risk acceptable if ALARP is achieved. Sometimes, the diagram is missing some commentary so it looks like that this region is simply the ALARP region - whatever that means.

Going hand in hand with the former definition though is that risks falling in the green area need not be treated at all and we'll come back to this.

Axes (as in plural of axis)

Often the nature of the axes is confusing. Take exhibit A (the one on the left), it has a y-axis but not x-axis. Sometimes you see risk magnitude shown as an x-axis but isn't risk level and risk magnitude the same thing?

Anyway, the diagram on the right has a bigger problem than that. It has no label on the x-axis but it does have two y-axes. The two plotted lines intersect at a point identified as the ALARP point.

But what is the significance of the intersect when different scales are used? I would argue that unless you identified the exact relationship between the two scales, there is no significance - not to ALARP or acceptability of the risk.

Two Questions

I see ALARP as not a question relating to acceptability - i.e. risk evaluation - but a question relating to risk treatment. Two different questions, but do both have to be answered?

If we follow the standard ISO 31000 RM process, the question of acceptability appears first and allows for the decision to not treat the risk, instead relying on existing controls. The standard does start to talk about cost-benefit considerations but stops short of requiring the achievement of ALARP at either the evaluation or treatment stages.

It appears to me that ALARP tends to be enshrined in regulations or case law. CASA aeronautical studies often include the following quote from an Australian High Court decision.

Where it is possible to guard against a foreseeable risk which, though perhaps not great, nevertheless cannot be called remote or fanciful, by adopting a means which involves little difficulty or expense, the failure to adopt such means will in general be negligent.

So, it seems that regardless of the inherent acceptability of a risk, it must still be treated to ALARP2. Meaning that you need to answer both questions separately.

  • Have I treated this risk to a level ALARP?
  • Is the residual level of risk acceptable?

My ALARP Diagram

In conceptualising my take on ALARP, I'm going to steal from the UK HSE department:

“‘Reasonably practicable’ is a narrower term than ‘physically possible’ … a computation must be made by the owner in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed in the other, and that, if it be shown that there is a gross disproportion between them – the risk being insignificant in relation to the sacrifice – the defendants discharge the onus on them.”

Those seem like some pretty clear directions. Risk on one axis and cost on the other. In order to make the slope of that line mean something, the cost scale needs to be calibrated to the risk scale but I have no idea how one would actually do this - maybe we'll tackle that one later. See below for a very rough, hand-drawn diagram. The ALARP point is rather hard to identify but it is the point where the slope of the line exceeds the cost-benefit limit.

Too often, I think we incorrectly lump related concepts into the same bucket and this leads to a blurring of the objectives of the process. In this case, ALARP fell in with risk evaluation when, I think, it should have remained separate and contained in the risk treatment part of the RM process.

Those risk professionals out there who possess ninja-like RM skills, can certainly short-cut the process to achieve the desire outcome but us grasshoppers3 should probably keep these concepts separate to ensure we cover off all requirements.

1. Adapted from ALARP's wikipedia page.
2. What this means for the standard, I'm not sure. I honestly hadn't thought about the implications of this thought process until I typed it just now.
3. I think I just mixed up kung-fu and whatever martial art ninjas do - no emails or dark-clad assassins please.

On the Shoulders of Giants

On the Shoulders of Giants

I can't rule out that I had already viewed this presentation and the words pathways and proximal became lodged in my mind - seeds sown to sprout some distant day in the future. But upon reading this document (again?)  I was struck by the apparent similarities with my proposed risk evaluation methodology, which was the subject of much ranting a few weeks ago - here, here, herehere and here.

Find out what presentation by reading on…

Wrapping Up PIGs .... For Now

Wrapping Up PIGs .... For Now

Since I don't just want to be thought of as some PIG-hating obsessive lunatic, lets wrap this thread up for the moment. Quick recap: The traditional likelihood-consequence matrix (PIG - see original post) is not particularly useful when dealing with aviation safety. Why? Because a graduated consequence scale fails to recognise the perilous nature of aviation and consequence as a dimension isn't particularly useful when evaluating latent conditions remote from the ultimate outcome (death by aviation).

Alternate approach: Instead of scoring the consequence directly, I've offered two alternative dimensions under the generic title of influence1 - proximity and pathways.

In wrapping this up, I thought I would discuss what I think is the rationale behind this approach of using slightly off-centre indicators.

Influential Behaviour

Influential Behaviour

Near the end of my last post, I used the Swiss-cheese model to highlight that many risk conditions1 worthy of attention are not necessarily proximate to the ultimate outcome. I also hinted in the post before that, that I thought this to be only half the story. To tell this story, let me introduce another accident causation modelling technique. It is called an AcciMap and it is gaining popularity because it offers a way of representing the relationships between events (these being things such as decisions, functions, tasks, actions, etc.). An AcciMap is set up in two dimensions with vertical lanes separating system levels of increasing generality as you move up and the horizontal axis having no fixed dimension or scale. The system levels begin very specific to the accident in question with equipment and actor activities making up the first two levels. The higher levels relate to organisational, regulatory authority and government policy and decision making.

One Step Back...

One Step Back...

In continuing this little series I've got going here, I'd like to just quickly go back over a couple of points from last time. I'm trying to keep these posts relatively short. So that means I may have moved on to my next point a little too quickly. I guess the crux of the last post was that a graduated consequence scale is inappropriate in an aviation safety context. My two main points to back up that statement were:

  • the potential for a catastrophic event is persistent to the primary aviation activity of flying from A to B; and

  • that given aviation is a complex socio-technical system, risk conditions (call them hazards, events, or even just risks) upstream of the ultimate condition (death by aviation) cannot be categorised effectively.

I tried a few of these arguments out on some colleagues and they seemed unconvinced. So, I'm going to work on them a bit more here - this blogging thing is much more for my benefit than yours but thanks for stopping by anyway ;).

One step back...

Vulnerability & Proximity

Vulnerability & Proximity

In my last post, I commenced a whinge about the PIG or as it is more commonly known, the likelihood-consequence matrix. I signed off that post with a promise to further the discussion on the risk matrix within an aviation safety context. Here goes...

Consequence is an inappropriate dimension to consider in aviation safety. For two reasons which I call vulnerability and proximity. Let's take them in turn.