UML and its Use-Case Modeling Professor Chen School of Business Gonzaga University Spokane, WA 99258 [email protected]

UML and its Use-Case UML and its Use-Case ModelingModeling

Professor Chen

School of Business

Gonzaga University

Spokane, WA 99258

[email protected]

UML (Use-Case Modeling), Dr. ChenTM -2

Methods vs. Modeling LanguagesMethods vs. Modeling Languages

A model has its purpose of structuring our thoughts

A method– is an explicit way of structuring one’s

thinking and actions– tells us:

• What to do• How to do it• When to do it• Why it’s done


Method, Modeling Language Method, Modeling Language and Processand Process

METHOD = +

Modeling Language

PROCESS


Process vs. MethodProcess vs. Method

A process is a group of activities that, if done correctly, will achieve an explicit goal.

A method, in contrast, is normally also considered as a set of related activities, but without explicit goals, resources, and rules.


What is a Process?What is a Process?

ProcessResourcesDocumentation,

Products, Models

etc.Humans,

computers

tools,

Information

What to do,

How to do it,

When to do it,

Why it should be done

Rules<<Util

ize>> [VALUE]


What is a Process?What is a Process?

ProcessResources Documentation,

Products, Models

etc.Humans,

computers

tools,

Information

What to do,

How to do it,

When to do it,

Why it should be done

Rules

<<Utilize>>

[VALUE]Software Development:

Process CONTEXT,

USER, STEPS

A process is a group of activities that, if done correctly, will achieve an explicit goal.


What is the UML?What is the UML? The Unified Modeling Language (UML)

is a graphical language for visualizing, specifying, constructing, and documenting the artifacts of a software-intensive systems.

UML is only a modeling language without a process– it is a lot easier to comprehend than a

natural language


What does UML give you?What does UML give you?

The UML gives you a standard way to write a system’s blueprints covering conceptual things, such as business processes and system functions, as well as concrete thins, such as classes written in a specific programming language, database schemas, and reusable software components.


How Applicable of UML?How Applicable of UML?

The UML is applicable to anyone involved in the production, deployment, and maintenance of software.


What is Visual Modeling?What is Visual Modeling?

VISUAL MODELING is a way of thinking about problems using (graphical) models organized around real-world idea.

UML is a product of VISUAL MODELING language.


Models are useful for ..Models are useful for ..

understanding problems, communicating with everyone involved

with project (customer, domain experts, analysts, designers, etc.)

modeling enterprise, preparing documentation, and designing programs and databases


Objectives of the ModelingObjectives of the Modeling

Modeling promotes: better understanding of requirements, cleaner designs, and more maintainable systems.


What is a Good Model?What is a Good Model?

A model is good when:

it is a relevant model it is possible to communicate it fits its purpose it captures the essentials


System Boundary

Use Case ACTOR

(Role)<deli

ver tan

gible valu

e to>

Customer Statistics

Sales Statistics

Signing an insurance policy

<send> <receive>

<initiate>

<communicate>

Figure: A Use-Cases Example


Purposes of the Use-Case Purposes of the Use-Case ModelingModeling

What a new system should do What an existing system already does


What is an Actor?What is an Actor?

An actor is a class not an instance. It represents a role, not an individual

user of the system. primary vs. secondary actors

– customer/user, developer, test teams vs. manager or board members

active vs. passive


Return books

Interlibrary loan

Borrow books

Library

Member

Figure: An Library Use-Cases Example

Do research

Read books, newspaper

Purchase supplies

Circulation Clerk

Supplier


SummarySummary Use-case modeling is a technique used to

describe the functional requirements of a system A use case is a set of sequence of actions

performed in the system. A scenario is an illustration or an example

(instance) of a use case or collaboration. An actor represents a role that an external entity

(user, hardware) plays in interacting with the system.


Insurancecompany

Insurance contract

Customer

1 0..*

0..*

1..*Figure 4.1: A simple mode of an insurance business. One insurance company hasmany (zero-to-many) insurance contracts. An insurance customer has many (zero-to-many) insurance contracts. Aninsurance contract is related to one insurance company. The insurance contract is related to many (one-to-many) insurance customers. The entities shown in the model are classes.

Figure 4.1: A simple mode of an insurance business. One insurance company hasmany (zero-to-many) insurance contracts. An insurance customer has many (zero-to-many) insurance contracts. Aninsurance contract is related to one insurance company. The insurance contract is related to many (one-to-many) insurance customers. The entities shown in the model are classes.


Figure 4.2 A Class in UML

Attributes

Operations

Name


Car

registration number dataspeed direction

Figure 4.3 A class car with the attributes registration number, data, speed, and direction. Attribute names typically begin with a lowercase letter


Car

registration number: Stringdata: CarDataspeed: integerdirection: Direction

Figure 4.4 The car with typed attributes

Invoice

+amount : Real+ date: Date + customer: String+specification: String-administrator: String

Figure 4.5: A class with public and private attributes


Invoice

+amount : Real+ date: Date=Current date+ customer: String+specification: String-administrator: String=“Unspecified”

Figure 4.6 A class with attributes and their default values


Invoice

+amount : Real+date: Date=Current date+customer: String

-number_of_invoices: integer = 0

Figure 4.9 An Invoice class

Public class Invoice{ public double amount; public Date date = new Date(); public String customer; static private int number_of_invoices = 0; //Constructor, called every time an objects is created public Invoice () { // Other Initialization number_of_invoices++; //Increment the class attributes } // Other methods go here};


Car

+ registration number: String+ data: CarData+ speed: integer+ direction: Direction

+ drive (speed: integer, direction: Direction)+ getData() : CarData

Figure 4.10 The car has attributes and operations. The operation drive has two parameters, speed and direction. The operation getData has a return type, CarData.


Author Computer

Figure 4.15 An author uses a computerThe author class has an association to theComputer class.

Figure 4.15 An author uses a computerThe author class has an association to theComputer class.

Uses

Associations: Normal Association


Person Car0..*

Figure 4.16 A person owns many (zero-to-many) cars,A car can be owned by many (one-to-many) persons.

Figure 4.16 A person owns many (zero-to-many) cars,A car can be owned by many (one-to-many) persons.

1..* Owns

Owned by


Person Car0..*

Figure 4.17 A navigable association says that a person can own many cars, but it does not say anything about how many people can own a car.

Figure 4.17 A navigable association says that a person can own many cars, but it does not say anything about how many people can own a car.

Owns


Insurancecompany

Insurance contract

1 0..*

0..*

Customer

1..*

Insurance policy

WebInsurance

policy0..1

0..1is expressed in an

Expressed

an

hasrefer to

has

refer to

Figure 4.18 A class diagram describing

an insurance business

Figure 4.18 A class diagram describing

an insurance business


Author

name : Stringage: Integer

0..* 1..*

Computer

name : Stringmoney: Integer

Bob:Author

name : Stringage: Integer

0..* 1..*

Bob’s PC COMPUTER

name : Stringmoney: Integer

Figure4.19 A class diagram and an object diagram and an example of the class diagram being instantiated


Node

Connects

Recursive Association

Figure 4.20 A network consists of many nodesconnected to each other.

Figure 4.20 A network consists of many nodesconnected to each other.

Person

married to


Insurance contract

Insurancecompany

1 0..*

refer to

contracts

Figure 4.22 Insurance company hasassociations to Insurance contract

Figure 4.22 Insurance company hasassociations to Insurance contract


Car Person

Figure 4.24 What roles do Person and Car play in this association?

Figure 4.24 What roles do Person and Car play in this association?

Another example of Roles in Association

drives **

drivercompany car


Person

married to

wife

husband

Figure 4.25 A husband is married to a wife. Both husband and wifeare people. If a person is not married, then he or she cannot play

the role of husband or wife, which means that the married toassociation is no applicable.

Figure 4.25 A husband is married to a wife. Both husband and wifeare people. If a person is not married, then he or she cannot play

the role of husband or wife, which means that the married toassociation is no applicable.

Roles in Association


Ready for the Next Run?Ready for the Next Run?


Insurance contract

0..*

0..*

Insurance policy

0..1

is expressed in an

Expressed an

Insurancecompany

1 has

refer to

1..*

has

refer to

insurer

Person

policyholder

husband

married to

wife

Figure 4.26 A class can play different roles in different associations. The model fromFigures 4.18 and 4.25 are combined. In this model, a person can play the role ofhusband, wife, or policyholder. The insurance company plays the insurer role.

Figure 4.26 A class can play different roles in different associations. The model fromFigures 4.18 and 4.25 are combined. In this model, a person can play the role ofhusband, wife, or policyholder. The insurance company plays the insurer role.

Roles in an Association


FileDirectory file name*

An example for Qualified Association

FileDirectory**


Insurance contract

0..*

Insurancecompany

1 0..*

1..*

Person Company

1..*

0..*

Figure 4.28 An insurance contract cannot have associations to both company and person at the same time

Figure 4.28 An insurance contract cannot have associations to both company and person at the same time

Or-Association


Insurance contract

0..*

Insurancecompany

1 0..*

1..*

Person Company

1..*

0..*

Figure 4.29 An or-association shows that only oneof the associations is valid at a time

Figure 4.29 An or-association shows that only oneof the associations is valid at a time

Or-Association

or


0..*

1..*

Insurance contract

Insurancecompany

1 0..*has

refer toinsurer

Results of Figures 4.26, 28, and 29: An insurance contract cannot have associations to both company and person at the same time

Results of Figures 4.26, 28, and 29: An insurance contract cannot have associations to both company and person at the same time

Company

0..*

1..*

0..*

has

refer toPerson

policyholder

husband

married to

wife

1..*

Or-Association

or


Insurance contract

0..*

0..*

Insurancecompany

1

1..*

Person

Figure 4.32 A ternary association connects three classes.Figure 4.32 A ternary association connects three classes.

Insurance policy

0..1

policyholder

insurer


Teams Person*

Members

Figure 4.34 A team is composed of team Members. One person could be a member of many teams. The model shows an example of a shared aggregation, where the people are the shared parts.

Figure 4.34 A team is composed of team Members. One person could be a member of many teams. The model shows an example of a shared aggregation, where the people are the shared parts.

*


Window

Text*

Listbox*

Button*

Menu*

Figure 4.36 The diamond shows the composition aggregate; the window contains ( is aggregated of) many menus, buttons, listboxes, and texts. All types of aggregation can have a name.


Window

Text*

Listbox*

Button*

Menu*

Figure 4.37 If there is more than one part in the same aggregate (wholeside into a single end.This is allowed for all types of aggregates. An aggregate has only one role name, and that is at the partside.

Contains


Vehicle

CAR Boat Truck

Figure 4.41 Vehicle is a general class (superclass) derived to specific classes (subclasses) via inheritance (generalization-specialization).


Vehicle

CAR Boat Truck

Figure 4.42 The same model as in Figure 4.41, but the inheritance takes the form of a tree (with only one hollow triangle).


Vehicle

CAR Boat Truck

Vehicle

CAR Boat Truck

Vehicle

Figure 4.43 A class hierarchy for vehicles. The Car class is subclass to Vehicle, but superclass to Sports car, Passenger car, and Truck.


Vehicle {abstract}

Drive() {abstract}

Car

drive()

Boat

drive()

drive() startsthe wheels

drive() startsthepropeller

Figure 4.44 The Car inherits the attribute color and the operation drive. The operation drive is redefined in the class Car and Boat. The class Vehicle is abstract, which also is marked. The notes below the classes are used to comment on a class diagram

Figure 4.44 The Car inherits the attribute color and the operation drive. The operation drive is redefined in the class Car and Boat. The class Vehicle is abstract, which also is marked. The notes below the classes are used to comment on a class diagram


drives

Vehicle {abstract}

colordrive() {abstract}

Car

drive()

Boat

drive()

*Person

Figure 4.45 A person drives vehicles.When the drive operation is called, the implementation used depended on whether the object used is a car or a boat. Vehicle is an abstract class showing the commonalties between cars and boats, including the association relationship to the Person class

Figure 4.45 A person drives vehicles.When the drive operation is called, the implementation used depended on whether the object used is a car or a boat. Vehicle is an abstract class showing the commonalties between cars and boats, including the association relationship to the Person class


Vehicle {abstract}

drive() {abstract}

Car

drive()

Boat

drive()

Propulsion Propulsion

Figure 4.47 Generalization-specialization with a discriminator that specifies that it is with respect to the propulsion that the subclass differ.


Object vs. Function-Oriented Analysis and Design

(Structured Analysis and Design)

The Library Information system

Object-oriented A/D

Decomposed by objects

or concepts

Structured A/D

Decomposed by functions

or processes

LibrarianCatalogue

LibraryBook

System

RecordLoans

AddResource

ReportFines


Figure: Conventional vs. Object - Oriented

Conventional Object-OrientedDecomposed by

Functions/process Objects/concepts

Types Data type

(e.g.) int num_of_employees

Class type class employee … }employee full-time, part-time;

Content One variable

contains one value.

e.g. number_of _employees

=20

One class containsmany objectsOne objecthas many attributes, operations

Documents

UML and its Use-Case Modeling Professor Chen School of Business Gonzaga University Spokane, WA 99258 [email protected]