Purdue Enterprise Reference Architecture.

A layered reference model for industrial networks that segments business IT from process control, widely used to design ICS network segmentation. It belongs to the OT / ICS / IoT category of cybersecurity.

A layered reference model for industrial networks that segments business IT from process control, widely used to design ICS network segmentation.

The Purdue Enterprise Reference Architecture (PERA), commonly called the Purdue model, organises industrial systems into hierarchical levels: Level 0 (field devices), Level 1 (basic control PLCs/RTUs), Level 2 (supervisory SCADA/HMI), Level 3 (site operations, MES, historians), a DMZ (Level 3.5), and Levels 4-5 (enterprise IT and external services). Traffic between levels is restricted by firewalls and DMZs to ensure that lower control levels remain isolated from corporate networks. The model underpins ICS guidance from ISA-99/IEC 62443 and is the conceptual basis for OT segmentation and detection programmes. Modern variants extend Purdue to address cloud connectivity, remote support, IIoT gateways, and OT/IT convergence while preserving the principle of strict zone-to-zone control.

Defences for Purdue Enterprise Reference Architecture typically combine technical controls and operational practices, as detailed in the full definition above.

Common alternative names include: Purdue model, PERA, Purdue reference architecture.