A higher reliability shutdown system will have a ___ Probability of Failure on Demand (PFD).

A higher reliability shutdown system is characterized by its improved ability to perform its intended safety function when required, which directly influences its Probability of Failure on Demand (PFD). The PFD is a metric that quantifies the likelihood that a system will fail to respond correctly upon demand.

In simpler terms, if a shutdown system is designed to be more reliable, it means that it is less likely to fail when its activation is needed. Consequently, a reliable shutdown system results in a lower likelihood of failure, thus leading to a lower PFD.

This concept is essential in risk management and safety engineering, as it emphasizes the importance of selecting and designing safety systems with higher reliability to minimize the risk of hazardous events. In the context of Layer of Protection Analysis (LOPA), understanding and applying this principle aids in evaluating and justifying the necessary layers of protection against potential failures or hazardous scenarios.