Conditions? Outcome? Which Is More Important For Safety?

BYGARETHLOCK

In May 2019, a student on a rebreather training class died when he made some errors in preparing his equipment prior to entering the water. Unfortunately, the mistakes that he made are the sorts of errors that many divers make all the time, but in this case, the errors that were made also aligned with conditions which meant that when he jumped in, his rebreather didn't support life, he went unconscious, sank, and drowned.

While executing a pre-dive checklist would have likely prevented THAT particular situation, there were multiple other factors that, if not corrected, could have led to a similar event in the future – almost the same event occurred two weeks prior. Still, those factors weren't picked up in a post-dive debrief. But how did it make sense for the diver not to use the checklist to trap the incorrect configuration effectively? What were the social, environmental, psychological, physiological, and cultural factors which made it easier not to use one?

CONDITIONS NOT OUTCOMES

We know what the causes of diving fatalities are - drowning, hypoxia, hyperoxia, hypercapnia, insufficient breathing gas, pulmonary barotrauma, AGE, blunt trauma, massive blood loss, hypothermia/hyperthermia – but we have less knowledge about the conditions that lead to errors that lead to these outcomes. Note error is not a cause of an accident, it is a precursor to an accident occurring, and if a report says the reason was 'human error', then the investigation stopped too early, and you need to start digging some more.

As with many aspects of bringing Human Factors into diving, the good thing is that researchers and practitioners from established high-risk environments have already done the hard work! In this case, the Institute of Nuclear Power Operations (INPO) analysed thousands of adverse events to determine the conditions surrounding error-like situations and their associated error precursors and produced a reference guide.

THE WITH MODEL

The article will briefly look at the different elements in the WITH model, how they can apply to diving and how we take them into account while managing risk and uncertainty in our diving and diving instruction. The WITH model is broken down into four areas Work.

Environment, Individual Capability, Task Demands and Human Nature, which are explained below.

Work Environment. The general influences of the workplace, organisational, and cultural conditions that affect individual behaviour, e.g., distractions, awkward equipment layout, complex procedures, atrisk norms and values, and a risk-seeking or causal attitude toward various hazards.

Task Demands. The specific mental, physical, and team requirements to perform an activity that may either exceed the capabilities or challenge the limitations of human nature of the individual assigned to the task, e.g., excessive workload, reduced time constraints, concurrent actions, unclear roles and responsibilities, and vague standards.

Individual Capabilities. The unique mental, physical, and emotional characteristics of a particular person that fail to match the demands of the specific task, e.g., unfamiliarity with the task, unsafe attitudes, lack of education, lack of knowledge, unpractised skills, inexperience, health and fitness problems, poor communication practices, and low self-esteem.

Human Nature. The generic traits, dispositions, and limitations common to all humans may incline them to err under unfavourable conditions, eg, habits, short-term memory, fatigue, stress, complacency/efficiency, and mental shortcuts or heuristics.

Error-precursors exist before the dive starts –they are latent conditions which 'come to life' when inevitable active failures like slips, lapses and mistakes happen. As these conditions are already present before the dive, we can be proactive, looking to reduce or eliminate the precursors and increase the chance of a successful outcome on a dive. This addresses Professor James Reason's point, "We can't change the human condition, but we can change the condition in which humans work".

Unfortunately, the quality of incident data in diving incidents is poor, with limited consideration given to the context surrounding the activity and the error-producing conditions that would have been present. As such, there isn't an opportunity to create a data-driven version of this table based on INPO data. Despite this data coming from the nuclear sector, the following explanations and examples should give you an idea of what to look for in your own diving operations to improve performance.

Given the limited space in this article, I can't go into detail about what each of these means, but you can download an extract from the INPO reference guide from above.

HOW TO USE THESE 'CONDITIONS' TO IMPROVE PERFORMANCE AND SAFETY IN DIVING

There are a couple of ways to use the table above and in the linked document. Firstly, you can use it as part of your own risk assessment and pre-dive preparation. Consider whether you've got a number of these precursors present. If so, think about what you will do to control the likelihood that a slip, lapse or mistake will happen given the different letters in the WITH model.

Secondly, given the insufficient data regarding incidents and accidents in diving, think about whether these error-producing conditions were present at the time of the dive. Whatever that person did, it must have made sense for them to do what they did, and these precursors make up part of that story. Remember, you need an error-likely situation (an action, a hazard, and conditions) for an adverse event to occur.

If you are part of an organisation that looks at quality and incidents/nearmisses, seriously consider looking at the conditions which appear in these incident/quality reports In industries with a relatively high level of safety maturity, investigations look at the extent of causes surrounding an event and whether they are present elsewhere in the business unit or company if spread geographically to stop them from happening elsewhere A more modern view is to look at the error-producing conditions surrounding an event and whether they can be changed too.

SUMMARY

Diving incidents and accidents always occur within a context and have a history behind them. That context comprises a hazard, some actions, and error-producing conditions. If we want to make a bigger impact on diving safety, rather than focus on the counterfactuals (what the diver didn't do, i.e., could have, should have), look at the conditions surrounding the event to see how it made sense for them to do what they did and see if those conditions can be changed, or at least highlighted before the event so divers and instructors are aware that they are more likely to make an error.

If you want to learn more about this specific event, visit wwwthehumandivercom/ifonly, where you can watch a documentary of the event told through the lens of human factors and also download a free guide which will allow you to run a workshop using the video as the basis for discussion.