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.