ICS (Industrial Control Systems) is the umbrella term for systems that control and monitor industrial processes — including SCADA, DCS, and PLC. These systems are found in manufacturing, energy, water treatment, and building automation. ICS differ fundamentally from traditional IT: availability has the highest priority, patch cycles are long, and many protocols were designed without security mechanisms. For your ISMS this means a separate risk assessment with tailored controls. Network segmentation between IT and OT networks is one of the most important measures. If your organization operates ICS, you should consider frameworks like IEC 62443 alongside ISO 27001.