7
Chapter 7:
The Object-Oriented Approach
to Requirements
Systems Analysis and Design in a Changing
The Unified Modeling Language and the
Object Management Group
7
 Object-oriented
modeling notation is Unified
Modeling Language (UML)
 UML
was presented to Object Management
Group (OMG) as standard modeling technique
 Purpose
of Object Management Group

Promote theory and practice of object technology
for development of distributed systems

Provide common architectural framework for OO
Systems Analysis and Design in a Changing World, 3rd Edition
4
7
Object-Oriented Requirements
 Systems
development process starts with
identification of events and things

Events are business processes that new system
must address

Things are problem domain objects involved in
business process
Systems Analysis and Design in a Changing World, 3rd Edition
5
7
Object-Oriented Approach Models
 Class
diagram – definition of system components
case diagrams and use case descriptions –
show user roles and how they use the system
 Use
sequence diagrams (SSDs) – define
inputs and outputs and sequence of interactions
between user and system for a use case
 Systems
 Statechart
diagrams – describe states of each
object
 Activity
diagrams – describe user activities
Systems Analysis and Design in a Changing World, 3rd Edition
6
Requirements Diagrams: Traditional and
OO Models
Systems Analysis and Design in a Changing World, 3rd Edition
7
7
The System Activities –
A Use Case / Scenario View
7
 Use
case analysis used to identify and define all
business processes that system must support
 Use
Case - single function performed by system
for those who use that function
 Actors

Role played by user

Outside automation boundary and organization
Systems Analysis and Design in a Changing World, 3rd Edition
8
7
Simple Use Case with an Actor
Systems Analysis and Design in a Changing World, 3rd Edition
10
7
Use Case Diagram with System Boundary
Systems Analysis and Design in a Changing World, 3rd Edition
11
7
Use Case of Customer Support System
Systems Analysis and Design in a Changing World, 3rd Edition
12
7
All Use Cases Including Customer
Systems Analysis and Design in a Changing World, 3rd Edition
13
Example of Order-Entry Subsystem with
<<Includes>> Use Cases (Figure 7-6)
7
<<includes>>
Common
Subroutines
Systems Analysis and Design in a Changing World, 3rd Edition
15
7
Developing a Use Case Diagram
 Starting
points for use case development

Use event table

Identify all actors of the system

Identify functions actors perform with system
 Develop
flow of activities to identify various
scenarios
 Common
internal use cases can be identified and
separated into different use cases
Systems Analysis and Design in a Changing World, 3rd Edition
16
Brief Description of Create New Order
Use Case
Systems Analysis and Design in a Changing World, 3rd Edition
7
19
Intermediate Description of the Telephone
Order Scenario for Create New Order
Systems Analysis and Design in a Changing World, 3rd Edition
7
20
Intermediate Description of the Web
Order Scenario for Create New Order
Systems Analysis and Design in a Changing World, 3rd Edition
7
21
Fully Developed Description of Telephone
Order Scenario for Create New Order
Systems Analysis and Design in a Changing World, 3rd Edition
7
22
Fully Developed Description of Web
Order Scenario for Create New Order
Systems Analysis and Design in a Changing World, 3rd Edition
7
23
7
Activity Diagram: Telephone Order Scenario
Systems Analysis and Design in a Changing World, 3rd Edition
25
7
Activity Diagram: Web Order Scenario
Systems Analysis and Design in a Changing World, 3rd Edition
26
Problem Domain Modeling –
The Domain Model Class Diagram
7
 Class
diagram is focal point of object-oriented
development
 Provides
definition of system components
 Contains
important class structural information for
implementation with object-oriented programming
 Provides
conceptual data model to describe
classes for database definition
 Consists
of problem domain classes and
implementation classes
Systems Analysis and Design in a Changing World, 3rd Edition
37
7
RMO Domain Model Class Diagram
Systems Analysis and Design in a Changing World, 3rd Edition
39
Relationships Between OO
Requirements Models
Systems Analysis and Design in a Changing World, 3rd Edition
7
41
7
Use Case Diagram for Inventory System
Systems Analysis and Design in a Changing World, 3rd Edition
42
Relationships Between OO
Requirements Models (Figure 7-28)
Systems Analysis and Design in a Changing World, 3rd Edition
7
43