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Aspects of IEEE P1471 Viewpoints in Unified Modeling Language (UML). Manzur Ashraf, BRAC University Humayra Binte Ali, Dhaka University Md.Mahfuz Ashraf, BRAC University ICCIT 2004, BRAC University. Terminologies. ‘View’:
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Aspects of IEEE P1471 Viewpoints in Unified Modeling Language (UML) Manzur Ashraf, BRAC University Humayra Binte Ali, Dhaka University Md.Mahfuz Ashraf, BRAC University ICCIT 2004, BRAC University
Terminologies ‘View’: One system can be described by 1-many views (conception/ idea) and each view can be described by 1-many graphical/textual ‘Model’ (Symbol) ‘Viewpoint’: To apprehend views at a certain level of detail [Roel] ‘Meta-layer/Meta-meta layer’ concept (in UML)is bounded. To conceive external concepts we use ‘Extension mechanism’ (UML). To make generalized viewpoints IEEE P1471 (98) motivation Fit UML to IEEE P1471
Classification 1 • Rich Hillard clustered the IEEE P1471 constructs in different conceivable groups. • Structural viewpoint • Behavioral viewpoints • User viewpoint • Distribution Viewpoint
A) Structural viewpoint: Concerns: – Defines the computational elements of a system and the organization of those elements. – What software elements comprise the system? What are their interfaces? How do they interconnect? What are the mechanisms for interconnection?
In UML, A class diagramdepicts the static structure of a system in terms of object classes, their attributes and operations and their relationships with one another. • Each class represents unique structure and a common behavior. • A class diagram can capture many other types of application semantics, such as association roles, role constraints, association classes, abstract classes, abstract operations, polymorphic operations, derived elements, class-scope attributes and operations, generalization discriminators, and semantic constraints among subclasses. Hence class diagram validates structural model according to IEEEP1471.
B) Behavioral viewpoints: • Concerns: • – Expresses the dynamic actions of and within a system. • - What are the kinds of actions does the system produce and participate in? How do those actions relate (ordering, synchronization, etc.)? What are the behaviors of system components? How do they interact? Here Modeling Methods are events, processes, states and operations on those entities.
- In UML, A state diagramdepicts the various state transitions or changes an object can experience during its lifetime, along with the events that cause those transitions. • -In UML, activity diagram represents internal process flow as opposed to processes controlled by external events. The state represents performance of the actions and transitions are triggered by completion of the actions. contd Results & internal aspect of system behavior
In UML, an interaction diagramis used to show the pattern of interactions among objects for a particular use case. There are two types of interaction diagrams. • 1) Sequence diagramsshow the explicit sequencing of messages, 2) collaboration diagramsshow the relationship among objects. Both are useful for developing a dynamic model of a system in terms of object interactions. Objects communicate with one another by sending messages.
C) User viewpoint: Concerns: – Captures the purpose, scope and policies for the system. – Roles played by the system. – Activities undertaken by the system. – Policy statements about the system.
A use case model is developed during the early phase of requirements analysis. Use case modeling helps developers gain a clear understanding of the functional requirements (overview) of the system, without having to worry about how those requirements would be implemented. Itrepresents a sequence of actions initiated by an actor.
D) Distribution Viewpoint: Concerns: - Defines how Command ,Control information and capabilities will be distributed. - Defines how enterprise data is defined, organized (structured), accessed and maintained. - What runs where? What talks to what? How do they talk? Distribution includes location and mechanisms to provide both transport and access between processes.
In UML, distribution viewpoint is performed by implementation diagram. Two types of implementation diagram are possible: a) Component diagram shows the structure of the source code and the relationship between modules; b) Deployment diagram shows the structure of the run-time environment and the physical structure of the installed platform/hardware on which the system is installed (running).
Classification 2 Roel W. clustered the IEEE P1471 constructs in different conceivable groups. • Conceptual and analysis viewpoints: The objective is to highly abstract software descriptions. • Logical design viewpoint: The objective is to describe the software design • Environmental / Physical viewpoint: The objective is to focus on the environment and physical aspects of the software.