HAZOP

Aim: To determine safety hazards in a proposed or existing system, their possible causes and consequences, and recommend actions to minimize the chance of their occurrence.

A team normally consists of:

• a study leader;

• a recorder (documents the meeting);

• a designer (explains the design);

• users (e. g. train driver, train operator);

• specialists (experts of the system or the study);

• and maybe a maintainer.

Basic guide words

Guide word	Meaning
NO OR NOT	Complete negation of the design intent
MORE	Quantitative increase
LESS	Quantitative decrease
AS WELL AS	Qualitative modification/increase
PART OF	Qualitative modification/decrease
REVERSE	Logical opposite of the design intent
OTHER THAN	Complete substitution
EARLY	Relative to the clock time
LATE	Relative to the clock time
BEFORE	Relating to order or sequence
AFTER	Relating to order or sequence