Disasters are either natural, such as floods, droughts, cyclones and earthquakes, or human-made such as riots, conflicts, refugee situations, and others like fire, epidemics, industrial accidents, and environmental fallouts. Often, the difference between them is marginal.

HAZOP:

Identify plant section on the P&I diagram; Define the design intent and normal operation conditions of the section; Identify a deviation from design intent or operating conditions by applying a system of guidewords like more flow, less/no flow etc.; Identify possible causes for, and consequences of, the deviation; action plan for addressing meaningful deviation that can result in harmful consequences; consultation and discussion with stakeholders and preparation of HAZOP Report

QRA:

Reconnaissance survey, data collection and discussion with proponent engineering staff; Hazard identification, preparation of hazard indices, PHA analysis; Generation of release scenarios for accidental release of hazardous chemicals, fuels etc. from BP and their handling due to natural and manmade causes; Computation of damage distances for credible release scenarios based on consequence analysis; Computation of frequency of release scenarios; Assessment of risks and design of Risk Mitigation Measures and Plan.