Object-Oriented Database Systems CSCI 397C-16ScopeThe following information presents an overview of the "Unified Modeling Language" (UML).This paper is associated with a corresponding PowerPoint presentation that will be presented inthe Chico CSCI 397C-16 class on November 2, 1999. The concepts and descriptions containedwithin are provided as a supplement to this presentation. My presentation focuses on the usage of UML within the conceptual and design phases of adevelopment process. The presentation seeks to illustrate how differing UML components anddiagrams build upon one another to increasingly define design based artifacts. I believe this willbe more interesting and educational than focusing upon UML notational constructs. IntroductionUML is a modeling language used to represent the conceptual and physical aspects of asoftware system. A model is used to specify information that must be included within the system.It is the development of the plan that will be used to construct the system. [BRJ99]Object-oriented modeling technologies supplemented the emergence of object-orientedprogramming languages in the 1970's and early 1980's. These programming languages werecreated as a more effective and real-world approach to developing software systems than thetraditional functional-oriented languages. Object-oriented modeling technologies weredeveloped to support these new type of programming languages.As a result, many modeling languages existed prior to the development of UML. Theseincluded Object-Oriented Software Engineering (OOSE), Object Modeling Technique (OMT),Fusion, and Yourdon. Each of these languages offered complete modeling solutions; however,each was recognized as having individual strengths and weaknesses. [BRJ99]As object-oriented technologies continued to grow and mature, a common set of ideas andexpectations began to develop. These expectations began to drive specific market requirementsinto the prevailing products. As a result, these technologies began to evolve toward one anotherUnified Modeling Language Prepared By: Keith Bryant 2 November 1999Object-Oriented Database Systems CSCI 397C-16and the OOSE and OMT authors recognized the need to begin a unification of the differentcomponents and ideas that remained unique. UML was created from this unification effort.The unification effort was begun in October 1994. This occurred when Rumbaugh wasemployed at Rational with Booch. Following is the major sequence of events in the developmentof UML: [BRJ99] October 1994: James Rumbaugh joins Grady Booch at Rational and begins the unificationof the Booch and OMT methodologies. October 1995: Alpha version 0.8 was released. October 1995: Ivar Jacobson joins Rational and begins the unification of the OOSEmethodology. June 1996: Alpha version 0.9 was released. January 1997: UML Version 1.0 was submitted to the Object Management Group (OMG)as a proposed standard modeling language. July 1997: UML version 1.1 was submitted for standardization. November 1997: UML version 1.1 was officially adopted as a standard by OMG. June 1998: UML version 1.2 released. October 1998: UML version 1.3 released.UML DiagramsUML consists of several different structural and behavioral type diagrams. Structural diagramsare static in nature with behavioral diagrams representing more dynamic type data. Differingstructural diagrams are shown as follows: Classes: Defines classes, interfaces, collaborations, and relationships. [BRJ99] Class-Responsibility-Collaboration Cards: Defines a high-level description of classresponsibilities. [Fowler97] Objects: Defines objects and their relationships at a given point in time. [BRJ99] Components: Defines components and their relationships from a perspective of asoftware architecture. [BRJ99] Deployment: Defines a configuration from a perspective of a hardware computingarchitecture. [BRJ99]Unified Modeling Language Prepared By: Keith Bryant 2 November 1999Object-Oriented Database Systems CSCI 397C-16Differing behavioral diagrams are shown as follows: Use Case: Defines a set of use case specifications, actors, and their associatedrelationships. [BRJ99] Sequence: Defines a set of interactions or messages between objects relative to orderor time. [BRJ99] Collaboration: Defines a set of interactions or messages between objects relative to time.[BRJ99] Statechart: Defines a type of state machine that consists of states, transitions, andevents. [BRJ99] Activity: Defines the flow from activity to activity. These emphasize the flow ofcontrol among objects. [BRJ99]Designing Using UML ComponentsRequirements are often generated as a set of ideas initiated from some type of marketing orproduct analysis. These types of analysis determine the business projections needed forjustification of the project. Once project approvals are obtained, a conceptual design can begin.Conceptual designs are typically begun by constructing a set of "Use Case Diagrams" from agiven set of user requirements. Use case diagrams attempt to model interactions between anactor or external event and the system. Actor interactions with the system assist indemonstrating activities within the use case. These activities define the various use cases whichare represented by the oval figures. [Larman98]Once the different use cases are determined. Use case narratives can be developed. Thesenarratives describe varying elements of each individual use case. These elements can includeactors, the purpose of the use case, an overview of what is does, a relative ranking of the usecase, and a cross reference to the stated requirement. The use case must include descriptionsof each individual actor action. This is an external event that initiates some system response. Itmust also include each individual system response(s) to these actions. Alternative responsesmay also be included. These may be high level exception type conditions. [Larman98]Unified Modeling Language Prepared By: Keith Bryant 2 November 1999Object-Oriented Database Systems CSCI 397C-16Once use case narratives are developed, a conceptual model can be created usinginformation from the narratives. A conceptual model forms the basis of the preliminary design