From lechner@cs.uml.edu Fri Apr 7 20:56:02 2006 From: Bob Lechner Subject: Demystifying UML (SMellor) To: sfrye@cs.uml.edu (Scot Frye), ralmonte@cs.uml.edu (Almonte), 05f5624 RJLRef: $PH/06s524/demystifyingUML_sm_ESD0603.txt "Demystifying UML" Embedded Systems Design (03/06) Vol. 19, No. 3, P. 22; Mellor, Stephen J. Unified Modeling Language (UML) can describe systems standardized by the Object Management Group (OMG) graphically and textually, and UML manifests itself as a notation for common object-oriented concepts--as opposed to a system analysis and design method--for embedded systems developers, writes OMG participant and software development trailblazer Stephen Mellor. UML enables developers to function at a higher level of abstraction and become more productive, as well as visualize concurrent behavior. UML is comprised of 13 diagram types, and the author lists the class diagram (which shows classes, attributes, associations, and generalizations), the state machine (which shows behavior over time in reaction to events), the use case (which captures requirements according to system-user interactions), and the sequence diagram (which shows synchronous and asynchronous object interactions) as the most commonly used diagrams for embedded systems. There are a variety of methods to integrate UML diagrams, with no agreement on the optimal approach. Also, there are no required links among diagrams prescribed by UML, nor any rule that there has to be one state machine for every class. UML is most often used on an informal basis (sketch), but is also employed to particularize software structure (blueprint) and as executable models that incorporate action language. Each of these usage methods facilitate distinct types of reuse: Sketches chiefly visualize solutions and communication between people, blueprints are good for design documentation, and executable models allow separate reuse of the application and implementation. "Using UML doesn't have to change your development process, but the introduction of UML is often seen as an opportunity to make some changes," Mellor writes. http://www.embedded.com//showArticle.jhtml?articleID=180205522