The STPA handbook (March 2018) defines loss identification as:

Identifying losses
Definition: A loss involves something of value to stakeholders. Losses may include a loss of human life or human injury, property damage, environmental pollution, loss of mission, loss of reputation, loss or leak of sensitive information, or any other loss that is unacceptable to the stakeholders.

How to: Identify Losses

1. Double click Losses in the STPA Project tree to open the new tab in the work space to the right.
2. Click the to create a New Loss.
3. Enter the Name of the loss.
4. Enter a unique ID for the new loss (example: L1, L-2).
5. Enter a description of the loss to distinguish it from other losses.
6. After creating the hazards the analyst can connect the losses with the hazards. This can also be done in the Relationship analysis or in the Hazards.

Here are some tips to prevent common mistakes when identifying losses:

• Losses can include any loss that is unacceptable to any stakeholder
• Losses should not reference individual components or specific causes like “human error” and “brake failure”
• Losses may involve aspects of the environment that are not directly controlled by the system designer
• Document any special considerations or assumptions made, such as losses that are explicitly excluded

After the losses of concern in the analysis are identified, the next step is to define the hazards related to these losses.