Disadvantage | Advantages | |
a) LOPA is not a tool for identifying hazards. | a) LOPA is effective in resolving disagreements related to risk. | |
b) LOPA may be excessive for simple or low risk decisions. | b) LOPA determines whether SIS or alternative means of protection are required and associated SIL if SIS is chosen. | |
c) LOPA may be overly simplistic for very complex systems. | c) LOPA complies with IEC 61511, clauses 8 and 9. | |
d) Risk comparison scenarios are only valid if same LOPA method is used throughout. | d) LOPA eliminates excess recommendation generation. | |