Avancier Avancier Methods UML distilled Including some Figures from the UML 2.4.1 standard (Know that UML is enormous It would take a week to learn all of it) Copyright Avancier Limited 2012 Unified Modeling Language Avancier ► “A standard language for writing software blueprints” ► “to visualise, specify, construct and document ► the artefacts of a software-intensive system” ► A specification language ► Grew out of need to specify an OO program ► Not originally designed for architects, business analysis or database design, but since extended to cover them. ► Bear in mind that a notation is not a panacea Copyright Avancier Limited 2012 UML is for OO system design Avancier All system design is about: ■ Defining the requirements for the system ■ Dividing the system into modules ■ Defining how those modules are related to each other. In OO system design ■ The requirements are defined as use cases ■ The modules are called classes ■ The two principal kinds of relationship are association and generalisation. Copyright Avancier Limited 2012 UML applies to object-oriented problem solving. Avancier ► UML embodies the tenets of object-oriented problem solving ► The domain is that part of the world that a system monitors or directs, containing entities and processes to be remembered or directed ► The run-time software system represents each entity and process as an object which has: ■ a structure or state - attribute values ■ behaviours – activities it can perform - operations ► Objects interact by sending each other messages. ► Each object is regarded as an instance of a class ► The model describes both domain and run-time software in terms of classes. A class is a template for a set of objects that defines ■ Structure – attribute types (data types) ■ Behaviour - operations (methods or functions) Copyright Avancier Limited 2012 But at a first-level of understanding, Avancier ► You can learn and use a lot of UML without knowledge of object-oriented software design ► UML is a set of diagram types. ► Each diagram is composed of ■ Boxes – nodes - things ■ Lines – arcs – relationships between things Copyright Avancier Limited 2012 14 UML diagram types Avancier ► Notice the division between structure and behaviour diagrams What a systems What a system is made of does/offers Copyright Avancier Limited 2012 Most popular diagram types Avancier Most popular Next most popular Copyright Avancier Limited 2012 A vastly simplified meta model of UML entities Avancier Structure ► Key entities in UML diagrams Class Behaviour Feature Relationship Process Behavioural Structural Feature Feature State machine Event State Operation Attribute Association Generalisation Action Transition Sequence Collaboration Guard Class Association Condition Action Role Role Message Copyright Avancier Limited 2012 Structure diagrams Avancier ► Class diagram: a system's classes, with their attributes and interrelationships ► Deployment diagram: execution environments and artefacts deployed onto hardware. ► Component diagram: components and the dependencies among these components. ► Package diagram: logical groupings in a system and dependencies among groupings. ► Composite structure diagram: the internal structure and possible collaborations of a class ► Object diagram: the structure of instances in a system at a specific time. ► Profile diagram: show stereotypes as classes at the metamodel level Copyright Avancier Limited 2012 Class diagram Avancier ► What are the basic components of a software system? ► How are they related? ► Software architects decompose applications into classes (not only data-entity-centric classes like the ones shown here). Copyright Avancier Limited Deployment diagram: Avancier ► execution environments and artefacts deployed onto hardware. Copyright Avancier Limited 2012 Component diagram: Avancier ► components and the dependencies among these components. ■ Components shown as boxes. ■ Interfaces shown as lollipops. ■ Dependencies shown in two ways. UML 1 Dependency arrow Component Component UML 2 Lollipop grabber Component Component Copyright Avancier Limited 2012 Package diagram: Avancier ► logical groupings in a system and dependencies among groupings. dependency Package Name Package Name Package Name Class 1 Class 2 Class 3 Copyright Avancier Limited 2012 Not illustrated here Avancier ► Composite structure diagram: the internal structure and possible collaborations of a class ► Object diagram: the structure of instances in a system at a specific time. ► Profile diagram: show stereotypes as classes at the metamodel level Copyright Avancier Limited 2012 Behaviour diagrams Avancier ► Use case diagram: processes that actors of a system are involved in, and dependencies between use cases. ► Activity diagram: step-by-step flow of work - shows the overall flow of control. ► State machine diagram the states and state transitions of a process. ► Interaction diagram ■ Sequence diagram: a sequence of message-based interactions between objects or components ■ Communication diagram: a sequence of message-based interactions between objects or components ■ Interaction overview diagram: an overview in which nodes represent communication diagrams. ■ Timing diagrams: a specific type of interaction diagram where the focus is on timing constraints. Copyright Avancier Limited 2012 Use case diagram: Avancier ► processes that actors of a system are involved in… Copyright Avancier Limited 2012 Activity diagram: Avancier ► step-by-step flow of work ► shows the overall flow of control. Copyright Avancier Limited 2012 State machine diagram Avancier ► the states and state transitions of a process. Copyright Avancier Limited 2012 State machine diagram Avancier Similar to activity diagrams Nodes: states rather than steps Lines: transitions "decorated” to indicate the triggering method call or condition Birth Born Change P’word 18th Birthday Logged On Id match Log Off Voter Waiting Vote Disconnection Authentication Death Enter Id Dead Logged Off Id mismatch Copyright Avancier Limited 2012 Interaction diagram Communication diagram: Avancier ► a sequence of message-based interactions between objects or components Copyright Avancier Limited 2012 Not illustrated here Avancier ► Interaction overview diagram: an overview in which nodes represent communication diagrams. ► Timing diagrams: a specific type of interaction diagram where the focus is on timing constraints. Copyright Avancier Limited 2012 UML diagram usage Avancier ► From “Empirical Assessment of MDE in Industry” ► Most of the diagram types appear in our training Copyright Avancier Limited 2012 Avancier training focuses on the more popular diagrams Avancier Structure diagrams ► Class diagram: a system's classes, with their attributes and interrelationships ► Deployment diagram: execution environments and artefacts deployed onto hardware. ► Component diagram: components and the dependencies among these components. ► Composite structure diagram: the internal structure and possible collaborations of a class ► Object diagram: the structure of instances in a system at a specific time. ► Package diagram: logical groupings in a system and dependencies among groupings. ► Profile diagram: show stereotypes as classes at the metamodel level Behaviour diagrams ► Activity diagram: step-by-step flow of work - shows the overall flow of control. ► State machine diagram the states and state transitions of a process. ► Use case diagram: processes that actors of a system are involved in, and dependencies between use cases. ► Interaction diagram ■ Sequence diagram: a sequence of message-based interactions between objects or components ■ Communication diagram: a sequence of message-based interactions between objects or components ■ Interaction overview diagram: an overview in which nodes represent communication diagrams. ■ Timing diagrams: a specific type of interaction diagram where the focus is on timing constraints. Copyright Avancier Limited 2012 Useful references Avancier For more on diagrams and notations http://avancier.website UML reference card http://www.holub.com/goodies/uml/ UML tutorial http://atlas.kennesaw.edu/~dbraun/csis4650/A&D/UML_tutorial/index.htm UML1.1 http://umlcenter.visual-paradigm.com/umlresources/nota_11.pdf Copyright Avancier Limited 2012 .