When creating network diagrams, which model is recommended to follow?

The Purdue model is widely recognized as a recommended framework for creating network diagrams in industrial automation and control systems (IACS). This hierarchical model categorizes the levels of an industrial system into distinct layers, which helps in clearly defining the separation between different functionalities and zones of operation.

The Purdue model breaks down an industrial system into different levels: from the enterprise level, down to control and field devices. This structured approach facilitates a better understanding of the system architecture and enhances security by visually differentiating the boundaries and interactions between various components. It underscores the importance of segmentation, which is crucial for cybersecurity strategies.

In contrast, the other models mentioned are not typically used in the context of industrial control systems. The Harvard model, for example, is more aligned with computing architectures and educational theories, while the MIT and Stanford models don't specifically address the unique needs or structures of industrial networks and cybersecurity practices. Thus, the Purdue model is preferred for its alignment with best practices in the cybersecurity field specific to IACS.