The extended system context describes the system interfaces and the detailed connection to the system actors and to the internal parts of the actors. In the previous post How to model a simple system context with SysML I've written about system context in general and the simple edition of system context that is simply spoken just a list of external systems and human actors who interacts with the system under development. The extended system context adds information about the interfaces at the...

The system context defines the system boundary and all system actors - humans and external systems - that interact with the system under development. It is one of the most important parts of the system model. Many artifacts of the system specification and architecture are relative defined to the definition of the system. Every system behavior and structural element is completely inside the system and not covered by any system actor. If you change the system boundary, you must also change the...

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...