As a consultant in the “performance” field, I read many articles, journals and books on ergonomics, continuous improvement strategies, process change, and behavioral psychology. One of the emerging trends in safety during the past several years has been Behavioral-Based Safety (BBS). The more I learn about BBS the more I am concerned about its use as the primary basis for improving safety. The safety philosophy of BBS compared to ergonomics is quite different.
BBS is focused on what people do, analyzes why they do it and then applies an improvement strategy to change what people do. The philosophy of ergonomics is that ergonomic interventions removes or reduces the sources of the risk. What “people do” is imbedded in the process or task design. I’ve always wondered about the wisdom of focusing on changing behaviors and/or habits as the primary method to improve safety. Everyone who knows someone who smokes or drinks to excess or has a teenager knows that behavior modification is quite challenging to say the least. The other problem is that the efforts to change the behavior may not result in the behavior that we really wanted to achieve. In other words, it is all too easy to induce an unwanted behavioral response if the reinforcement techniques are not well thought out. Are we relegating safety to the condition/response model?
An incident/accident investigation using BBS tends to concentrate on the human—assigning human error as the root cause. After all, in BBS the solution to the problem revolves around changing the behavior, i.e. the response to the condition. Whereas in ergonomics, the root cause delves beyond the human and looks closely at environmental, organizational, cognitive and physical factors that caused the human to perform/behave the way s/he did. In the book, Behind Human Error (2nd ed.; Woods, Dekker, Cook, Johannesen, and Sarter; Ashgate, 2010), the authors present two types of thinking: “first story” and “second story”. First story thinking sounds very similar to BBS. In an incident investigation first story thinking stops at what people did and affixes “human error” as the cause. “Second story” thinking looks at what happened and asks, “Why did the person(s) involved think what they did was perfectly acceptable and a reasonable path of action?” Second story analysis strives to remove the hindsight bias that comes from knowing the outcome of the particular incident. Instead of assigning someone blame, such as “s/he didn’t wear PPE”, the second story looks at the “why’s” for that person decision not to wear PPE. By considering cognitive, physical, operational and organizational elements, the second story seeks to determine the process imbalances that set the stage for whatever happened. The authors go to state that errors in actions and decisions are a symptom (of system problems), not a cause.
This isn’t to say that behavioral research isn’t important and shouldn’t be used in an effort to improve safety. However, to primarily focus on changing the habits, behavior and culture without first considering ergonomics and human factors will result in the continuation of errors and injuries. From my perspective as an ergonomist, the knowledge from behavioral research is to be applied to the design of systems, tasks and tools to minimize the undesirable outcomes potentially linked to those behaviors.
Now one might argue that despite well designed workstations, people tend to engage in risky/unsafe behaviors. For instance, people sit on “ergonomically” designed chairs with bad posture. So, one could argue that the application of BBS could be used in this instance. I’d like to point out that people are not designed to sit in one position all day long and no matter how the chair is designed. For good reasons people will alter their postures throughout the day. Some postures will be good and others will be not-so-good. So, is it the person’s behavior that is to blame or is it the requirement of the task, i.e. person must stay sitting all day long, that is the cause of their behavior?
Let’s take another example. Say a worker is standing at the end of a conveyor. His job is to take the widget from the conveyor and put it into bins. The worker is observed picking up the widget, twisting his back and throwing the widget into the bin. The bins are positioned behind and to the side of the worker. Let’s say the widget weight 40lbs and the workers lifts/throws 2000 widgets/day. One should not be surprised if that worker experiences a lower back strain or arm/hand repetitive motion disorder given the amount of weight and frequency of the job and the body mechanics of the worker. One could say that the worker is using poor body mechanics and if he would only hold his hands a certain way when lifting or move his feet instead of twisting that he wouldn’t have gotten hurt. Or, one could say the worker is using those “poor” body mechanics due the location of the bins. If the bin was repositioned or even better, if a chute was attached from the end of the conveyor to the bin so that all the worker would have to do is push the part down the chute then the risk would be significantly minimized and therefore the injury wouldn’t occur. One solution focuses on the behavior of the person (“human error”), the other solution focuses on the reasons for the behavior and fixes it so that the behavior doesn’t occur.
The two examples clearly show the difference in philosophy of BBS and ergonomics. Assigning the blame on the human is often easier and quicker instead of assigning blame and finding solutions to the system, process or task. However, changes to the system, process or task will achieve the goal of zero injuries much more reliably and sustainably compared to relying on human behavior.
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