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Human Factors vs. Common Sense

Author: Scott Linn, MS CHFP, is an active partner at Critical Reliability Consulting, providing valuable Human Factors content and… common sense to an uncommon world.  Scott was a flight test engineer with the Boeing Company for 32 years.  He has a master’s degree in Psychology/Human Factors and is a Certified Human Factors Professional by BCPE.  He consults on HF, CRM and safety issues and he urges you not to talk on your phone while driving.

The study of Human Factors is the cornerstone of understanding Crew Resource Management.  Human Factors (HF) is often characterized as just common sense.  This is not accurate.  Human Factors is a science with experimentation and hard data as its underpinning, while common sense is, well, just not that common.

A primary driver for asserting the false equivalence of HF and common sense is money.  This is not surprising.  If it is accepted that human factors is a valid scientific process with applicable results in a vast array of workplaces and activities where humans are involved (and that’s a lot), then money must be spent to implement the changes and provide the tools and accommodations resulting from established HF principles.  That could be expensive.  If on the other hand these ideas are merely common sense available to pretty much everyone as a consequence of existing, then workers will simply get on with the job as the natural order of things and there will be little, if any, extra expenditure or training required.  Such a false equivalence may be profitable in the short run, but much more expensive in the long run.

The origins of Human Factors as a science can be traced to the 1940s and a time when machines were rapidly changing and evolving to fight a war.  Many machines, notably tanks, ships and especially airplanes changed and became more complex so rapidly that there was little time for training and it was left to the operators to just figure it out; to understand exactly what the designers had in mind and how to make the machine work properly to achieve the desired result.  The undesired result was a lot of crashed and wrecked tanks, ships and especially airplanes.  At last people started wondering why this was happening and began investigating what had gone wrong and why.  As the jet age came into being, the stakes got higher and things moved faster.  An early example of a human factors design failure is the Lockheed P-80/T-33.  The four-step procedure for ejecting was written on a placard attached to the frame of the canopy.  Step one was to “blow the canopy”.  It was hoped the pilot in urgent need of departing the airplane had memorized steps two through four.

A pioneer in the field of HF was Paul Fitts, who preached the gospel of fitting the job to the person and not trying to fit the person to the job.  He is also notable for developing Fitts’ Law, which mathematically describes the relationship between a target device (e.g., a switch or button) and how fast it can be actuated by an operator based on the distance and size of the target.  At last rational, experimental data began to be used in design and applied in the operation of complex systems.  Human capabilities and limitations were also being studied in greater detail and quantified into usable data that could be practically applied.  A key area of inquiry was into the function of human memory, which had widespread implications for training and operation of complex systems.  Memory is not foolproof, so the concept of memory aids and checklists, in wide use today, came about.  The major limitation of such aids and tools is that they must be used to be effective, unfortunately this is not always the case.  Human performance is a major area of human factors research, and it is important to realize that it is variable.  How any individual performs a task or job may depend on several factors, including fatigue, stress, environmental conditions (too hot, etc.), workload, training and simply individual differences.

We live in a world of complex systems; nuclear power plants are one example.  The cause of the accident at the Three Mile Island nuclear plant in Pennsylvania in 1979 can be directly traced to incorrect and inadequate human factors design, in that a key indicator light which would have shown what the developing problem was, had been partially hidden from the operators by a different control and indicator.  Another more relevant example most of us are familiar with is the proliferation of cell and smartphones in the past few decades, and the desire by many to use these devices while driving a car.  Repeated and irrefutable research has shown that having a phone conversation while driving poses risks similar to driving while legally drunk.  The same areas of the brain needed for the driving task are used for the conversation, and they do not time-share well.  A phone conversation is fundamentally different from a conversation with someone in the car.  Hands-free devices make no difference; we drive with our brains, not with our hands.  Despite laws and training, accidents due to talking or texting while driving continue to increase.  Common sense or even knowledge might dictate avoidance of such a risk, but it has not done so.

A more recent outgrowth of Human Factors research and development is the concept of Crew Resource Management, or CRM.  In complex systems and high-reliability organizations or HROs (simply defined as a setting where teams of people operate the complex systems, and where even small errors may have dire and catastrophic consequences), the use of others as a resource for correct and efficient system operation is a key element of accomplishing the desired tasks and achieving the desired outcomes.  Examples of HROs include aviation/aerospace, healthcare, transportation systems such as rail and air traffic control, refineries and as noted above, power plants.  Other complex industrial settings also qualify.  Human Factors and CRM are closely linked to safety, which is typically a major initiative in an HRO.

Common sense is notoriously uncommon. Everyday frustrations with door handles, shower controls, setting the time on and operating digital devices and navigating websites are testament to this. So, stating that ‘Human Factors is just common sense’ betrays a lack of understanding of both Human Factors and common sense.  Anyone who describes Human Factors as common sense implies that the interaction of physical, biological, social, cultural and engineering sciences, and the application of this to the design of tasks and work (including the tools and environments of work), is obvious and straightforward, and can therefore be done by anyone based on knowledge and skills that are commonly available and obvious.  This couldn’t be further from the truth.  Since everyone has a body and also seeks shelter and builds structures to enhance their lives, if Human Factors is just common sense then we must conclude that disciplines such as surgery, dentistry, architecture and civil engineering are also just common sense, and pretty much obvious to everyone as to how to proceed.  Good luck with that.

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