Model based systems engineering (or MBSE) is a methodology for organizing your engineering information exchange and workflow that centers everything around models rather than around documents. Put simply, documents are textual descriptions of workflows, connections, features, requirements, and more. They’re read by engineers to understand how to work with a part of a system. Models have textual elements, but also contain graphical representations of how the elements of a system interact. The connections between different parts of the system are represented visually, rather than just being described in text.

It may seem like a minor difference, but model based systems engineering opens up wholly new ways of thinking about and interacting with your system.