Human factors and Homer Simpson

Human Factors 101 - Making it easy for Homer to do the right thing.

It can sometimes be difficult to explain in simple terms what ‘human factors’ means, or what value it adds. The next time that you’re asked to define human factors, the following explanation may help. It could also form the basis of a ‘safety moment’ on the subject of human reliability.

When visiting the central control room of a chemical site a few years ago I did a quick sketch of one of the control room operators in my notebook (yes, I really did draw this myself, I need to consider a change of career. . . ). I promised not to reveal this operator’s real name, so let’s just call him Homer.

Homer’s main tasks are to monitor key plant conditions, make adjustments from the control room to ensure that the plant runs smoothly and safely, and to communicate with the operators who work outside on the chemical plant.

Now, let’s imagine that there’s a serious process upset on the site. How might Homer respond?

Maybe there’s dozens of alarms going off, lots of calls on the radio from operators outside on the site, Homer hasn’t seen this situation before, his supervisor is on a lunch break, the emergency response procedures aren’t very clear, all the buttons on his control panel look the same, Homer is concerned about shutting down the plant (Mr Burns always talks about production targets), he’s been working overtime recently due to staff shortages, he’s worried about his wife Marge who is ill, his son Bart is in trouble at school (again), and on top of all that, he hasn’t had a donut for at least half an hour and his blood sugar is dangerously low.

All of these things will influence how Homer responds to the process upset. They might even make it more likely that, unintentionally, he won’t do the right thing.

These conditions are often referred to as Performance Influencing Factors, because they do exactly that. They Influence our Performance.

The question that I’m asked most often is “why do people behave like they do?“, or perhaps, “why do smart people sometimes do dumb things?“. The answer is quite simple. Our actions and decisions are ‘nudged’ and shaped, sometimes without us knowing, by these Performance Influencing Factors (PIFs). Many of the Topics outlined on (such as fatigue, workload, competence and supervision) are actually Performance Influencing Factors.

If we’re investigating an incident or a near-miss, we should be looking for these Performance Influencing Factors. They are the context in which behaviours occur and will help us to understand why people did what they did. We can identify the factors or conditions that set people up to fail. And we recognise that these same factors could create the conditions that will set other people up to fail as well. When we know which of these factors played a role in the event, we can put measures in place to address them.

Managing these factors will be more effective than simply telling people to ‘be more careful’. When we identify these factors that influence behaviours, we’re less likely to think that the train driver, pilot, control room operator or nurse did something ‘dumb’, or didn’t do the right thing, and is therefore to blame.

But there’s so much more to human factors than contributing to an investigation when something goes wrong. Although this may be useful, should we wait for an incident to occur before we attempt to understand the human factors aspects?  If we do, we may be missing a trick. Proactively addressing these Performance Influencing Factors could increase human reliability and therefore prevent near-misses, accidents and tragedies.

Performance Influencing Factors, PIFs (sometimes referred to as Performance Shaping Factors, PSFs)
Performance Influencing Factors (pdf version available)

To get started, list the activities or tasks you and your team really need to get right – the most critical tasks that you perform. ‘Critical’ means different things to different organisations – tasks may be critical because of health, safety, environmental, quality or commercial reasons. Now examine the Performance Influencing Factors that might impact human performance on these critical tasks. I’ve included the most common Performance Influencing Factors in the attachment, but you may wish to create your own list. These factors are listed under three sections – People, Work and Organisation (hence the tagline on my humanfactors101 logo).

By identifying and making these factors optimal (before an adverse event occurs), you will be able to set yourself and your team up for success, instead of setting people up for failure.

In Homer’s case, we could provide training in foreseeable emergencies and upsets (maybe using simulators to examine likely scenarios); we could improve the procedures; ensure that supervision is always available; improve the design of the control panel; ensure that the right numbers of people are available; address conflicts and unclear priorities; improve fatigue management and so on. The key point is that these factors can be identified in advance by talking to Homer, understanding his tasks, and assessing his workplace.

It’s important to note that many of these factors are not within Homer’s control. Mr Burns and the management team are responsible for these influences on Homer and his colleagues. As James Reason said: “you cannot change the human condition, but you can change the conditions in which humans work” (2003).

Some organisations include these influencing factors in their front-line risk assessments, so that they are communicated to everyone and considered in pre-start assessments, or when something changes (such as when the task doesn’t go to plan, or when new people join the work party).

The above is a simple Human Reliability Assessment. Understanding and managing these Performance Influencing Factors is the essence of human factors and key to improving human reliability.

Therefore, a simple definition of human factors could be “making it easy for Homer to do the right thing”. This is human factors 101.

Human Factors 101 - Making it easy for Homer to do the right thing.