The technical term System is relative and depends on the viewpoint. From one viewpoint an entity is a system, from another one it is a subsystem or an external system. It is a role that is applied to an entity. You loose this flexibility of changing the viewpoint if you model a system context with SysML and the model elements Block (for the system) and Actor (for the users and external systems). By definition, the model element Actor represents an...

In many respects, the future of systems engineering can be said to be “model-based.” (INCOSE Vision 2020) Model Based Systems Engineering (MBSE) is a key technology to respond to the need of developing more and more complex systems in more and more complex (network) organizations. I work in the MBSE domain since 10 years. I've written a book about MBSE with SysML, parts of the SysML specification and several papers. These are static unidirectional medias. I like to talk about MBSE in...