A Hazard and Operability Analysis (HAZOP) is a structured and systematic technique for system examination and risk management, when it is necessary to identify potential hazards in a system and identifying operability problems likely to lead to nonconforming products arising from operability problems even if not hazardous in itself, and unwanted events.

A HAZOP analysis is well suited for analyzing risks related to equipment and utility systems. The method is used during the design or installation of a new plant or process, or after major modifications. When there are unique hazards such as environmental hazards and quality or cost issues associated with the operation. Following a major incident involving fire, explosion, potential exposure. To justify why a particular code of practice, guidance, industry code or regulation is not being followed. This is especially relevant when working in fields where competing and conflicting guidelines are the norm.

HAZOP assumes risk events are caused by deviations from design or operating intentions. A set of guide words are used as a systematic way of identifying such deviations.

This approach is a core feature of the HAZOP methodology that helps focus the brainstorming, stimulate the discussions and trick the imagination of team members when exploring potential deviations. It is a qualitative risk and an inductive risk assessment tool, meaning that it is a “bottom-up” risk identification approach. This means that every part of a system that can fail or misbehave will be identified by subject matter experts (SMEs) to predict deviations based on past experiences and general subject matter expertise.

The HAZOP analysis is often the first step for defining the URS and drafting the qualification and validation protocols.


A HAZOP analysis asks questions like: