(144a) Independent Protective Layers and Human Response: Using Human Factors Principles for Verification of Effectiveness of Safeguards

Process Safety Management strives to “Keep the Tiger in the Cage”; to protect people, the environment, and our business from hazards associated with the process. Designing an inherently safer process is our top priority. When controls are required, we sometimes rely on administrative controls (people responding to alarms or following a procedure) as part of our safeguard layers of protection, especially when engineering controls are not practical.

However, it can be difficult to determine accurate verification criteria or how to improve the robustness of administrative controls. Using human factors principles to understand what shapes human performance is essential in determining when to use and how to improve these safeguards or when to install engineering controls. This paper will discuss how to create a safeguard verification system for human factors to improve situation awareness and corrective action response. First, we will examine the importance that situation awareness plays in an operator’s ability to detect, decide, and/or deflect when using administrative controls. Next, we will describe how to identify error traps and operational dilemmas that can reduce the effectiveness of safeguards. Lastly, we will discuss the concepts of learning from normal work which can help improve procedure writing, preventative maintenance programs, and selection of independent protective layers.

By employing these human factors principles, we can create a verification program for safeguards in our PHA process so that we can better support human response and decision-making.