This document is intended as a typical guideline and reference book that may be applied at petroleum, petrochemical and chemical facilities. It is suggested that this document is used as a practical reference to prepare the safety review requirements for these and related industries, and their process safety management systems. This publication is intended to provide guidance to I-IAZOP (Hazard and Operability) and What-If review teams associated with the petroleum, petrochemical, and chemical industries. It describes the nature, responsibilities, methods and documentation required in the performance of such reviews. This ensures the reviews are conducted in a timely, effective and professional manner as may be prescribed by a company`s Process Safety Management (PSM) Policy. A completed review report can be used to demonstrate to interested parties that a process hazard analysis has been accomplished and all possible actions have been examined and/or implemented to eliminate major hazards. This document can also be referred to by review team members, It will serve as a reminder of their duties and responsibilities in the performance of the required reviews and report development.