UML / UML 2.0 Diagrams

(Part I)

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Overview of the 13 diagrams of UML

Structure diagrams1. Class diagram2. Composite structure diagram (*)3. Component diagram4. Deployment diagram5. Object diagram6. Package diagram

Behavior diagrams1. Use-case diagram2. State machine diagram3. Activity diagram

Interaction diagrams1. Sequence diagram2. Communication diagram 3. Interaction overview diagram (*)4. Timing diagram (*)

(*) not existing in UML 1.x, added in UML 2.0

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UML principle: diagram vs. model

• Different diagrams describe various facets of the model

• Several diagrams of the same kind may coexist

• Each diagram shows a projection of the model

• Incoherence between diagrams (of the same or of different kind(s)) correspond to an ill-formed model

• The coherence rules between different kinds of diagrams is not fully stated

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Use case diagram

• Displays the relationship among actors and use cases, in a given system

• Main concepts:o System – the system under modelingo Actor – external “user” of the systemo Use case – execution scenario, observable by

an actor

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Class diagram

• The most known and the most used UML diagram

• Gives information on model structural elements

• Main concepts involvedo Class - Objecto Inheritanceo Association (various kinds of)

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UML Class

• Gives the type of a set of objects existing at run-time• Declares a collection of methods and attributes that

describe the structure and behavior of its objects

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Properties of UML classes

• May own featureso Structural (data related) : attributeso Behavioral : methods/operations

• May own behavior (state machines, interactions, …)

• May be instantiated o except for abstract classes that can NOT be directly

instantiated and exist only for the inheritance hierarchy

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Decode class symbol adornments

Class name in italics: abstract

class

Underlined attribute = class

attribute

Simple class box: passive class

Vehicle

Automobile

+wheelsNO : integer

-serialNo : integer

+fillTank(In volume:real):real

Door

+wheelsNO : integer

-serialNo : integer

door 1 *

+fillTank(In volume:real):realFeature visibility +,

-, #,~

Attributes area

Method(operation)

area

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Object

• Instance of a class• Can be shown in a class diagram• Notation

ford : Automobile

wheelsNO=4

serialNo=123ABC567

wheelsNO=4

serialNo=123ABC567D

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Relations

• Inheritance• Association (Aggregation, Composition)• Refer to UML_Class_Relation.ppt

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Interface

• Declares set of public features and obligations• Specifies a contract, to be fulfilled by classes implementing the

interface

• Not instantiable (abstract class)

• Its specification can be realized by 0, 1 or several classes

• Interfaces hierarchies can be defined through inheritance relationships

• In UML 2.0, interface may also include attributes and a special form of a state machine called a protocol state machine.

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Interface definition and use examples

<<interface>>InteractionPrimitives

tokenExchange(

<<interface>>SecureInteraction

checkConsistency

retrieveLast()

checkConsistency()

tokenExchange()

SatelliteSecureInteraction

The class Satellite provides implementation for the 3

operations

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Service Requester vs. Provider

Interface SiteSearch is realized (implemented) by SearchService.

Interface SiteSearch is used (required) by SearchController

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Package

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• Used to reflect the organization of packages and their elements.

• When used to represent class elements, package diagrams provide a visualization of the namespaces (domains).

• Subdivide models to permit teams of developers to manipulate and work effectively together

• Typically a logical view (compared against the component/subsystem/deployment diagrams)

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Component

• Its definition evolves from UML 1.x to UML 2.0• In UML 1.x - deployment artifacts• In UML 2.0 – structured classes Modular unit with well-defined interfaces that is

replaceable within its environment Autonomous unit within a system

•Has one or more provided and required interfaces•Its internals are hidden and inaccessible•A component is encapsulated•Its dependencies are designed such that it can be treated as independently as possible

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A component can have…• Interfaces

– An interface represents a declaration of a set of operations and obligations

• Usage dependencies– A usage dependency is relationship which one element requires

another element for its full implementation• Ports

– Port represents an interaction point between a component and its environment

• Connectors – Connect two components (links are used to connect objects)– Connect the external contract of a component to the internal

structure

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Subsystem

• Used to decompose the physical organization of large-scale system at the highest level of abstraction

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Nodes and Deployment

Nodes: Devices and Execution environment

Focused on the artifacts that deploy executables (i.e., .exe, .dll, .lib files)

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