Adding Structure to Our Lives

UML and SysML classify diagrams as showing structure, interactions, or behavior.  Structural diagrams show the system's pieces and relationships among those parts.  Interaction diagrams show the communications among those pieces.  Behavioral diagrams specify how the pieces respond when they receive messages.  (Please note:  I used the term "pieces" specifically because it is not a UML or SysML term.  A piece could be a class, object, file, structure, block, or part) Structure diagrams serve similar purposes in both UML and SysML, it with some important differences.  For Systems Engineers, the entities represent abstract concepts about a system's decomposition.  For software developers, the entities represent code that will be created (i.e., generated or handwritten) to implement the software application. The next few articles discuss structural diagrams.