Tutorials/IEC 62443 standard/Target security level (SL-T)
IEC 62443 standard

Target security level (SL-T)

Your target for each zone

IEC 62443 menu → SL-T

For each zone and conduit, define the expected target security level (SL-T, from 0 to 4) based on the facility's actual criticality and the consequences of compromise.

Screenshot: iec62443-sl-t-01.png 📷 Screenshot to be added img/iec62443-sl-t-01.png

What you will do

  1. Assess each zone's criticality, including safety, production and environmental impacts in the event of compromise.
  2. Derive an SL-T for each zone and conduit. The most critical zones, such as safety and SIS zones, require the highest target.
  3. Document the justification for the selected level; it will be included in the report.

Pitfall to avoid. SL-T is based on the consequence of compromise, not its probability. Do not confuse it with a conventional risk rating.

← Zone and conduit modellingAchieved level (SL-C) and gap →
FR