Three Human Factor Patterns in Safety Incidents

Virtually every safety incident has a human element in one form or another. They follow three basic patterns:

Design decisions—Even if every individual at a plant is experienced, thoroughly trained, works conscientiously and pays attention, incidents can happen because a decision was made about an element of process design, plant location, or whatever, that put the facility in harm’s way. The 2011 Fukushima Daiichi disaster in Japan is a good example. Reports following the incident suggest that the operators were well trained and did follow procedures correctly, but the disaster occurred because people had decided to locate the plant so closely to the water. There was nothing the operators or systems could do to overcome the sheer power of the tsunami.

Operator training (inadequate or insufficient) —The number of disasters that escalated due to an operator making an incorrect, or inadvisable decision are too many to count. While most process control and safety instrumented systems are supposed to limit such effects, it is not possible to imagine every possibility and prepare for it. Other situations may make an operator deliberately ignore normal safety procedures for the sake of getting a unit back into production.

Maintenance practices—Like design decisions, allowing a plant to deteriorate due to inadequate maintenance practices, is also a human decision. Some problems are simply the result of neglect where a sensor fails to operate and nobody does anything about it. Others involve a technician repairing a device incorrectly or doing a sloppy job, leaving it in a condition where it cannot perform a critical function.

Human Factors—People Are Part of the Solution

Various studies have estimated the losses in process plants caused by operator errors at more than $6 billion annually. However It wouldn’t be fair to assume people as the problem. People who are well trained and deeply familiar with a process can use their intuition and knowledge to analyze and respond to a situation that the automation system designers never imagined. Clever people can find new solutions when facing an unfamiliar situation.

Problems are more subtle, consider a lax safety culture. If a company does not stress the importance of following safety procedures, operators have been known to cut corners. When safety is identified as critical to a company’s vision and culture, people at every level will think more about it and behavior will change for the better. Conscientious people that are aware of the importance of safety and have been thoroughly trained on correct practices and procedures, working in a well-designed and maintained plant should expect day-to-day operations without incidents or injuries.