Compare methods

	FMEA	Hazard and Operability Study (HAZOP)
Field	Decision-making	Disaster Studies
Family	MCDM	Process / pipeline
Year of origin	1995	2016
Originator	Stamatis, D. H.	ICI (1960s practice); codified in IEC 61882 and CCPS guidelines
Type	Risk priority via product of O·S·D ratings	Structured guide-word deviation analysis of process designs
Seminal source	Stamatis, D. H. (1995). Failure Mode and Effect Analysis: FMEA from Theory to Execution. ASQ Quality Press ISBN: 978-0-87389-300-8	International Electrotechnical Commission. (2016). IEC 61882:2016 Hazard and operability studies (HAZOP studies) — Application guide (2nd ed.). IEC, Geneva.
Aliases	—	HAZOP Study, Hazard and Operability Analysis, Guide-Word HAZOP, Deviation Analysis
Related	8	3
Summary	FMEA (Failure Mode and Effects Analysis) is a ranking multi-criteria decision-making (MCDM) method introduced by Stamatis, D. H. in 1995. It turns a decision matrix of alternatives scored on multiple criteria into a structured, reproducible result.	A Hazard and Operability Study, or HAZOP, is a structured, team-based examination of a process design that systematically searches for deviations from the design intent and judges whether each deviation could create a hazard or impair operability. Its signature device is the guide word: terms such as 'No', 'More', 'Less', 'Reverse' and 'Other than' are combined with process parameters like flow, pressure and temperature at each part of the system to provoke a complete and disciplined set of 'what if it went wrong this way?' questions. IEC 61882 is the international application guide that defines the technique, its guide words and its workflow, while the CCPS Guidelines for Hazard Evaluation Procedures situates HAZOP among the core hazard-evaluation methods of process safety. The method's power lies in its rigorous, qualitative completeness: by walking every node and every guide word, a multidisciplinary team aims to leave no credible deviation unconsidered.