I have some question about Hazard analysis

How a system shoud be partioned in order to apply checklist and Hazop techniques?
which are the most appropriate keywords for the different aspect of the system?
How to verify mitigation have been correctly applied?(this is important)
How it it possible to quantify events related to human acrivities? How to quantify events relared to new system?

                                           bye  
                                        barboncino(italy)