The XDSM (eXtended Design Structure Matrix) is a tool used to visualize MDO processes. It is an extension of the classical Design Structure Matrix commonly used in systems engineering to describe the interfaces among components of a complex system. In a computational MDO context, the complex system is the MDO architecture, the components of the system are pieces of software (disciplinary analyses, optimization algorithms, surrogate models, etc.) used by the architecture, and the interfaces between components are the data exchanged by this software. Because the architecture also contains an algorithm defining the order in which the software is run, a numbering system and lines depicting the process are introduced in the diagram. In this way, we are able to capture all of the data and process flow of an architecture in a single diagram.
The full details of how to construct and interpret XDSMs are the subject of this paper
Check out the pyXDSM GitHub repository for further documentation and the installation instructions.