IEC61511 Part 3 Annex F, Page 46: F.1 Introduction. This annex describes a process hazard analysis tool called Layer of Protection Analysis (LOPA). The method starts with data developed in the Hazard and Operability analysis (HAZOP study) and accounts for each identified hazard by documenting the initiating cause and the protection layers that prevent or mitigate the hazard. The author's emphasis has been added to the quotation. See also clause F.2 on the same page.
2.
“A review of Layers of Protection Analysis (LOPA) analyses of overfill of fuel storage tanks” by ChambersColinWildayJillTurnerShane, Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, SK17 9JN. HSE Research Report RR716, published 07/09.
3.
Page 10, section 2.3.5, analysis of LOPA for company A in HSE Research Report RR716, published 07/09.
4.
TCE, April 201, page 56, published by The Institution of Chemical Engineers.
