UMLUML

The Unified Modeling Language

Brief Summary of UML(The Unified Modeling Language)

The UML is a language forThe UML is a language for•visualizingvisualizing•specifyingspecifying•constructingconstructing•DocumentingDocumenting

It is used to understand, design, browse, configure, It is used to understand, design, browse, configure, maintain, and control information about systems.maintain, and control information about systems.

The UML uses mostly graphical notations to express the The UML uses mostly graphical notations to express the OO analysis and design of software projects.  OO analysis and design of software projects. 

Simplifies the complex process of software designSimplifies the complex process of software design

Object Oriented ModelingObject Oriented Modeling

Goals of UML

•Provides a common language for describing both components and architectures

•Supports language-independent analysis and design

•Provides a common method for developing both information systems and technical applications

•Enables seamless transition from analysis to design to implementation

•Scales from small to large projects

•Facilitates iterative development

UML Assessment•UML is messy, imprecise, complex.

•You don’t have to know or use every feature of UML any more than you need to know or use every feature of a large software application or programming language.

•UML can be and has been used in many different ways in real-world development projects.

•UML is more than a visual notation. UML models can be used to generate code and test cases.

Model:

•Models are the language of designer, in many disciplines

•Models are representations of the system to-be-built or as-built

•Models are vehicle for communications with various stakeholders

•Models allow reasoning about some characteristic of the real system

Types of UML DiagramsTypes of UML Diagrams

Use Case DiagramUse Case Diagram

Class DiagramClass Diagram

Sequence DiagramSequence Diagram

Collaboration DiagramCollaboration Diagram

State DiagramState Diagram

Activity DiagramActivity Diagram

Interaction DiagramInteraction Diagram

Deployment DiagramDeployment Diagram

Component Diagram Component Diagram

This is only a subset of diagrams … but are most widely usedThis is only a subset of diagrams … but are most widely used

Use Case DiagramUse Case Diagram

Used for describing a set of user scenarios

Mainly used for capturing user requirements

Work like a contract between end user and software developers

Use Case Diagram (core components)

Actors: A role that a user plays with respect to the system,including human users and other systems. e.g.,inanimate physical objects (e.g. robot); an external system that needs some information from the current system.

Use case: A set of scenarios that describing an interaction between a user

and a system, including alternatives.

System boundary: rectangle diagram representing the boundary between the actors and the system.

Use Case Diagram(core relationship)

Association: communication between an actor and a use case; Represented by a solid line.

Generalization: relationship between one general use case and a special use case (used for defining special alternatives)Represented by a line with a triangular arrow head toward the parent use case.

Use Case Diagram(core relationship)

Extend: a dotted line labeled <<extend>> with an arrow toward the base case. The insertion of additional behavior into abase use case that does not know about it. The base class declares “extension points”.

<<extend>>

Include: a dotted line labeled <<include>> beginning at base use case and ending with an arrows pointing to the include use case. The insertion of additional behavior into abase use case that explicitly describes theinsertion

<<include>>

Use Case DiagramsUse Case Diagrams

Library System

Borrow

Order Title

Fine Remittance

ClientEmployee

Supervisor

• A generalized description of how a system will be used. 

• Provides an overview of the intended functionality of the system

Boundary

ActorUse Case

Use Case DiagramsUse Case Diagrams(cont.)(cont.)

(TogetherSoft, Inc)

Use Case DiagramsUse Case Diagrams(cont.)(cont.)

•Pay Bill is a parent use case and Bill Insurance is the child use case. (generalization)

•Both Make Appointment and Request Medication include Check Patient Record as a subtask.(include)

•The extension point is written inside the base casePay bill; the extending class Defer payment adds the behavior of this extension point. (extend)

Class diagramClass diagram A class is a collection of objects with common A class is a collection of objects with common

structure, common behavior, common structure, common behavior, common relationships and common semanticsrelationships and common semantics

Classes are found by examining the objects in Classes are found by examining the objects in sequence and collaboration diagramsequence and collaboration diagram

A class is drawn as a rectangle with three A class is drawn as a rectangle with three compartmentscompartments

Classes should be named using the vocabulary of Classes should be named using the vocabulary of the domainthe domain Naming standards should be createdNaming standards should be created e.g., all classes are singular nouns starting with a capital e.g., all classes are singular nouns starting with a capital

letterletter Detailed class diagrams are used for developersDetailed class diagrams are used for developers

Class representationClass representation

Each class is represented by a rectangle subdivided into Each class is represented by a rectangle subdivided into three compartmentsthree compartments NameName AttributesAttributes OperationsOperations

Modifiers are used to indicate visibility of attributes and Modifiers are used to indicate visibility of attributes and operations.operations. ‘‘+’ is used to denote +’ is used to denote PublicPublic visibility (everyone) visibility (everyone) ‘‘#’ is used to denote #’ is used to denote ProtectedProtected visibility (friends and visibility (friends and

derived)derived) ‘‘-’ is used to denote -’ is used to denote PrivatePrivate visibility (no one) visibility (no one)

By default, attributes are hidden and operations are visible.By default, attributes are hidden and operations are visible.

An example of Class An example of Class

Account_Name- Customer_Name- Balance

+addFunds( )#withDraw( )+transfer( )

Name

Attributes

Operations

OO Relationships

There are two kinds of RelationshipsThere are two kinds of Relationships Generalization (parent-child Generalization (parent-child

relationship)relationship) Association (student enrolls in course)Association (student enrolls in course)

Associations can be further classified Associations can be further classified asas AggregationAggregation CompositionComposition

Subtype2

Supertype

Subtype1

OO Relationships: Generalization

- Generalization expresses a parent/child relationship among related classes.

- Used for abstracting details in several layers

Regular Customer

Loyalty Customer

Customer Example:

Regular Customer

Loyalty Customer

Customer or:

Represent relationship between Represent relationship between instances of classesinstances of classes Student enrolls in a courseStudent enrolls in a course Courses have studentsCourses have students Courses have examsCourses have exams Etc.Etc.

Association has two endsAssociation has two ends Role names (e.g. enrolls)Role names (e.g. enrolls) Multiplicity (e.g. One course can have many Multiplicity (e.g. One course can have many

students)students) Navigability (unidirectional, bidirectional)Navigability (unidirectional, bidirectional)

OO Relationships: Association

Association: Multiplicity and RolesAssociation: Multiplicity and Roles

University Person

1

0..1

*

*

Multiplicity

Symbol Meaning

1 One and only one

0..1 Zero or one

M..N From M to N (natural language)

* From zero to any positive integer

0..* From zero to any positive integer

1..* From one to any positive integer

teacheremployer

Role

Role

“A given university groups many people; some act as students, others as teachers. A given student belongs to a single university; a given teacher may or may not be working for the university at a particular time.”

student

Class DiagramClass DiagramOrder

-dateReceived-isPrepaid

-number :String-price : Money

+dispatch()+close()

Customer

-name-address

+creditRating() : String()

Corporate Customer

-contactName-creditRating-creditLimit

+remind()+billForMonth(Integer)

Personal Customer

-creditCard#

OrderLine

-quantity: Integer-price: Money

-isSatisfied: Boolean

Product* 1

1

*Employee*

{if Order.customer.creditRating is"poor", then Order.isPrepaid must

be true }

* 1

Constraint

(inside braces{}}

Operations

Attributes

Name

Association

Multiplicity: mandatory

Multiplicity: Many value

Multiplicity: optional

Generalization

[from UML Distilled Third Edition]

class

0..1

Association: Model to ImplementationAssociation: Model to Implementation

Class Student {Class Student { Course enrolls[4];Course enrolls[4];}}

Class Course {Class Course {Student have[];Student have[];

}}

Student Courseenrollshas

* 4

OO Relationships: Composition

Class W

Class P1 Class P2

Composition: expresses a relationship among instances of related classes. It is a specific kind of Whole-Part relationship.

Whole Class

Part Classes

Automobile

Engine Transmission

Example

OO Relationships: Aggregation

Class C

Class E1 Class E2

AGGREGATION

Aggregation: expresses a relationship among instances of related classes. It is a specific kind of Container-Containee relationship.

Container Class

Containee Classes

Bag

Apples Milk

Example

Aggregation vs. CompositionAggregation vs. Composition

•CompositionComposition is really a strong form of aggregation •components have only one owner •components cannot exist independent of their owner •components live or die with their owner e.g. Each car has an engine that can not be shared with other cars.

•AggregationsAggregations may form "part of" the aggregate, but may not be essential to it. They may also exist independent of the aggregate. e.g. Apples may exist independent of the bag.

Sequence Diagram(make a phone call)Sequence Diagram(make a phone call)

Caller Phone Recipient

Picks up

Dial tone

Dial

Ring notification Ring

Picks up

Hello

Sequence Diagram:Object interactionSequence Diagram:Object interaction

Self-CallSelf-Call: A message that an Object sends to itself.

Condition: indicates when a message is sent. The message is sent only if the condition is true.

Iteration

Condition

A B

Synchronous

Asynchronous

Self-Call

[condition] remove()

*[for each] remove()

A sequence diagram displays an interaction as a two-dimensional chart. The vertical dimension is the time axis; time proceeds down the page. The horizontal dimension shows the roles that represent individual objects in the collaboration.Each role is represented by a vertical column containing a head symbol and a vertical line—a lifeline.

Sequence Diagrams – Object Life SpansSequence Diagrams – Object Life Spans

CreationCreation Create messageCreate message Object life starts at that pointObject life starts at that point

ActivationActivation Symbolized by rectangular Symbolized by rectangular

stripesstripes Place on the lifeline where Place on the lifeline where

object is activated.object is activated. Rectangle also denotes when Rectangle also denotes when

object is deactivated.object is deactivated. DeletionDeletion

Placing an ‘X’ on lifelinePlacing an ‘X’ on lifeline Object’s life ends at that pointObject’s life ends at that point

Activation bar

A

BCreate

XDeletion

Return

Lifeline

Sequence DiagramSequence DiagramUser Catalog Reservations

1: look up ()

2: title data ()

3: [not available] reserve title ()

4 : title returned ()

5: hold title ()

5 : title available ()

6 : borrow title ()

6 : rem ove reservation ()

•Sequence diagrams demonstrate the behavior of objects in a use case

by describing the objects and the messages they pass.

•The horizontal dimension shows the objects participating in the interaction.

•The vertical arrangement of messages indicates their order.

•The labels may contain the seq. # to indicate concurrency.

Message

Interaction Diagrams: Collaboration diagramsInteraction Diagrams: Collaboration diagrams

User

Catalog

Reservations

start

1: look up2: title data

3 : [not available] reserve title

4 : title returned

5 : hold title

6 : borrow title

6: remove reservation

5: title available

•Shows the relationship between objects and the order of messages passed between them.  between them. •The objects are listed as rectangles and arrows indicate the messages being passed •The numbers next to the messages are called sequence numbers. They show the sequence of the messages as they are passed between the objects. •convey the same information as sequence diagrams, but focus on object roles instead of the time sequence.

State DiagramsState Diagrams ((Billing Example)Billing Example)

State Diagrams show the sequences of states an object goes through during its life cycle in response to stimuli, together with its responses and actions; an abstraction of all possible behaviors.

Unpaid

Start End

PaidInvoice created payin

gInvoice destroying

State DiagramsState Diagrams (Traffic light example)(Traffic light example)

Yellow

Red

Green

Traffic LightState

Transition

Event

Start

Activity DiagramActivity Diagram

Activity DiagramActivity Diagram

Built during analysis and designBuilt during analysis and design PurposePurpose

Model business workflowsModel business workflows Model operationsModel operations

Developed by analysts, designers Developed by analysts, designers and implementersand implementers

The Physical ModelThe Physical Model The The component diagram component diagram shows the shows the

relationship between software relationship between software components, their dependencies, components, their dependencies, communication, location and other communication, location and other conditions.conditions.

A A deployment diagramdeployment diagram illustrates the illustrates the physical deployment of the system into a physical deployment of the system into a production (or test) environment. It shows production (or test) environment. It shows where components will be located, on where components will be located, on what servers, machines or hardware. It what servers, machines or hardware. It may illustrate network links, LAN may illustrate network links, LAN bandwidth & etc.bandwidth & etc.

The Physical ModelThe Physical ModelThis diagram shows the relationships among This diagram shows the relationships among software and hardware components involved in real software and hardware components involved in real estate transactions. estate transactions.

Component DiagramComponent Diagram

Captures the physical structure of the Captures the physical structure of the implementationimplementation

Built as part of architectural Built as part of architectural specificationspecification

PurposePurpose Organize source codeOrganize source code Construct an executable releaseConstruct an executable release Specify a physical databaseSpecify a physical database

Developed by architects and Developed by architects and programmersprogrammers

Deployment DiagramDeployment Diagram

Captures the topology of a system’s Captures the topology of a system’s hardwarehardware

Built as part of architectural Built as part of architectural specificationspecification

PurposePurpose Specify the distribution of componentsSpecify the distribution of components Identify performance bottlenecksIdentify performance bottlenecks

Developed by architects, networking Developed by architects, networking engineers, and system engineersengineers, and system engineers

Architecture and the UMLArchitecture and the UML

OrganizationPackage, subsystem

DynamicsInteraction, State machine

Design View Implementation View

Process View

Components Classes, interfaces,collaborations

Activity, Active classes

Deployment View

Nodes

Use Case ViewUse cases