True or False: The reliability of an IPL is unaffected by human intervention.

The correct answer is that the reliability of an Independent Protection Layer (IPL) is affected by human intervention. In practical applications of Layer of Protection Analysis (LOPA), human factors play a crucial role in determining the effectiveness of safety systems, including IPLs.

Human actions—or inactions—can introduce variability and potential uncertainty into the operation of safety systems. For example, if an IPL relies on human intervention, such as manual activation of a safety measure, any errors, delays, or misjudgments made by personnel can directly impact the effectiveness of that layer of protection. Conversely, if the IPL is fully automated and designed to operate independently of human control, its reliability may be less susceptible to human error, but the premise remains that human factors still influence the overall safety process during maintenance, training, and operational conditions.

By recognizing the influence of human intervention, safety assessments can create a more accurate depiction of risk and the required reliability of each IPL in place. This appreciation for the human factor is crucial in designing effective safety systems to mitigate potential hazards adequately.