HAZOP/ LOPA Study is performed at the early stage of the design phase of a project, after the process design is finalised and before the detailed design commenced, during the FEED stage. (A HAZOP (Hazard and Operability study) is a detailed hazard and operability problem identification process, and a LOPA (Layer of Protection Analysis) is a risk assessment methodology for evaluating plant hazards in reducing the frequency and/or consequence severity of hazardous events.)

Reference Definition by Aiche.org/ccps: A HAZOP/ LOPA Study is the extension of a HAZOP Study to include aspects of a LOPA, including selecting identified scenarios for further analysis; evaluating the initiating event frequency, consequence severity and effectiveness of IPLs on an order-of-magnitude basis; considering enabling conditions and/or conditional modifiers as appropriate when evaluating scenario risk; and comparing the calculated scenario risk to a risk goal to determine the adequacy of existing risk control measures.

Related Definitions in the Project: The Engineering; Process Safety Engineering; HSE Management; Project Management