Plant Hazard Analysis and Safety Instrumentation Systems

6.0. Human Reliability Analysis in Brief

From various internationally published estimates, it is found that in the world, out of the total number of plant accidental scenarios, around 60–90% are on account of human failure in different forms, and the rest are on account of technical deficiencies of equipment and control systems, or on account of other issues. Naturally, human reliability assessment or analysis claims is a major focus. In Fig. V/6.0-1A, a short depiction (Ref: Clause 6.4 also) has been presented to demonstrate understanding of how does it happens.

Figure V/5.4-1 Quantitative risk analysis process.

In almost all the PHA methods discussed ...