Barriers are a foundational tool used in HPI programs and processes, but they can also be misunderstood. Today, we will look at what barriers are, what they aren’t, and how they should be used most effectively. This is an important concept to understand prior to learning the various tools and applying the various techniques available to us as Human Performance Improvement practitioners.
So what are barriers? Barriers are essentially safe-guards to prevent something from happening. In a safety program, barriers can be designed to prevent workers from contacting electrically energized equipment or falling from a height. In a Human Performance Improvement program, barriers are designed to prevent errors from escalating.
If barriers are used to prevent errors from escalating, then what isn’t a barrier designed to do? For one, a barrier will not prevent an error from occurring. This is a common misconception. We can use guard rails to prevent someone from falling (the consequence), but the guard rails won’t prevent the person from losing their balance (the error). Terminal barriers will not prevent someone from inadvertently contacting a terminal block (the error), but they will prevent that inadvertent contact from making an electrical connection when used correctly (the consequence). Using caution tape will not prevent an employee from mistakenly walking up to the wrong equipment (the error), but that caution tape should prevent an employee from working on the wrong equipment when used correctly (the consequence).
Knowing this, how can we effectively apply barriers in our Human Performance Improvement programs to get the most help without excessive burdens on our workers? The trick is to know how to layer barriers in a method that gives us “Defense in Depth.”
Referring to the figure, Defense in Depth attempts to prevent errors from escalating by layering barriers in a methodical way. By viewing this layering of barriers as slices of Swiss cheese, it can be easily seen that the various barriers used must complement each other. No single barrier can prevent everything, but at the same time, no combination of barriers can be allowed to have the same weakness. A hole in one barrier should be stopped at the next level.
Barriers (or defenses) can be broadly grouped into four groups: Administrative, Physical, Oversight and Behavioral. Barriers should be used from all four categories (when possible) to be most effective.
Administrative barriers are processes and procedures. These can be written (preferably), but aren’t always. These barriers lay down the groundwork of how employees are supposed to interact with equipment. Wearing PPE, such as hearing protection, or mandating a lock out/tag out program are examples of an administrative barrier.
Physical Barriers are engineered barriers designed to prevent employees from interacting with equipment in certain ways. Guard rails, mufflers and interlocks are examples of physical barriers.
Oversight Barriers include managerial oversight. These barriers typically include coaching and observation to ensure employees are behaving in a manner that is expected. Often times, after an incident, supervisors find out after the fact that employees were doing things in a way that wasn’t up to expectations.
Behavioral Barriers are the defenses we put in place at the point of contact. When we typically think about HP tools, behavioral barriers are the tools that come to mind first. These are the self-checks, communication tools and checklists that are all designed to improve an employee’s self-awareness and situational awareness. These tool also account for an employees perceived level of risk, which can be different than actual risk (future post).
Note that, over time, our defenses can break down due to drift (future posting) – this is essentially allowing the holes in the cheese to get bigger, which allow the gaps in our barriers to overlap. The behavioral barriers prevent errors from escalating while the administrative and managerial defenses counteract drift to ensure adherence to the behavioral barriers. Purposely defeating a physical barrier should only be done according to procedures under certain circumstances. Defeating a physical barrier just to make a job easier is a violation.
For more information on barriers or to see how we can help, please contact us.