Tutorials/IEC 62443 standard/Achieved level (SL-C) and gap
IEC 62443 standard

Achieved level (SL-C) and gap

Your actual current position

IEC 62443 menu → SL-C

Assess the security level currently achieved (SL-C) for each zone and conduit. The tool calculates the gap against SL-T and highlights the areas that require priority treatment.

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

What you will do

  1. Assess each Foundational Requirement (FR) for the relevant zone or conduit.
  2. Let the tool calculate the resulting SL-C and the gap against SL-T.
  3. Sort zones by decreasing gap to prioritise the remediation plan.

Pitfall to avoid. A zero gap does not mean that a zone has no residual risk. It means that the achieved level matches the target. If SL-T was underestimated, a zero gap is misleading.

← Target security level (SL-T)SIS mode (optional) →
FR