System Level Hazards and Losses can be defined in multiple ways in the RM Studio STPA Module. You can create them via the ‘System Level Hazards’, respectively ‘System Level Losses’ section in the STPA Project Overview or via the ‘Relationship’ section. Both are described in the following.

System Level Hazards may be linked to System Level Losses. Additionally, System Level Hazards can be refined by sub-hazards. As a consequence of this a Hazard may link to a Hazard or a Loss.

System Level Losses cannot be refined. Therefore, a Loss may only link to a Hazard.

How to: Create System Level Hazards in ‘System Level Hazards’

1. Double click the ‘System Level Hazards’ section in the STPA Project Tree and notice the new tab opening in the work space to the right of the STPA Project tree.
2. Click ‘+’ icon in the toolbar to create a new System Level Hazard. By default, the hazard is labelled “New Hazard”.
3. Select the newly created hazard.
4. Change the Name of the hazard
5. Optionally provide an ID (e.g. H-1, H-2, etc.)
6. Leave the “Available in Step 1” checkbox ticked unless you want to explicitly exclude this hazard in STPA Step 1 (for example this hazard has refined hazards and you want to make sure only the refined hazards are available in STPA Step 1).
7. Add an optional description
8. Optionally, select any constraints, the hazard relates to (in the screenshot the list of constraints is empty, hence nothing can be selected). You can save your progress now to allow the name to save for the list (‘Ctrl+S’ keys or save icon at the top-left).

How to: Create System Level Losses in ‘System Level Losses’

The sequence is identical to the one described for System Level Hazards with the only difference that you have to double click the ‘System Level Losses’ at the beginning.

How to: Create System Level Hazards in the ‘Relationship’

1. Double click the ‘System Level Hazards’ in the STPA Project Tree and notice the new tab opening in the work space to the right of the STPA Project tree.
2. Right click on an empty space in the ‘Relationship Canvas’ to bring up the context menu
3. Select ‘Hazard’ under ‘Create’. This will create a new System Level Hazard. By default, the hazard is labelled “New Hazard”.
   
4. Select the newly created hazard.
5. Use the ‘General Information’ tab as described in the how to above.