Systems Analysis and Design Alan Dennis Barbara Haley

Systems Analysis and Design Alan Dennis, Barbara Haley Wixom, and Roberta Roth John Wiley & Sons, Inc. Slides by Candace S. Garrod Red Rocks Community College 14 - 1 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Unified Modeling Language Chapter 14 14 - 2 Power. Point Presentation for Dennis, Wixom,

Key Definitions Object-oriented techniques view a system as a collection of self-contained objects which include both data and processes. The Unified Modeling Language (UML) the object modeling standard adds a variety of techniques to the field of system development. 14 - 3 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

BASIC CHARACTERISTICS OF OBJECT-ORIENTED SYSTEMS 14 - 4 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Object Concepts An object is a person, place, event, or thing about which we want to capture information. Each object has properties (or attributes). The state of an object is defined by the value of its properties and relations with other objects at a point in time. Objects have behaviors -- things that they can do -which are described by methods (or operations). Objects do not use primary or foreign keys, instead each instance is assigned a unique identifier (UID) when it is created. 14 - 5 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Classes and Objects 14 - 6 Power. Point Presentation for Dennis, Wixom, & Roth

Class A class is a general template we use to define and create specific instances or objects. 14 - 7 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Object An object is an instantiation of a class. An object is a person, place, event, or thing about which we want to capture information. 14 - 8 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Messages and Methods Messages are information sent to objects to trigger methods 14 - 9 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Encapsulation and Information Hiding Encapsulation is simply the combination of process and data into a single entity. The principle of information hiding suggests that only the information required to use a software module be published to the user of the module. 14 - 10 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Inheritance Classes are arranged in a hierarchy Superclasses or general classes are at the top Subclasses or specific classes are at the bottom Subclasses inherit attributes and methods from the superclasses above them Classes with instances are concrete classes Abstract classes only produce templates for more specific classes 14 - 11 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Class Hierarchy 14 - 12 Power. Point Presentation for Dennis, Wixom, & Roth Systems

Inheritance 14 - 13 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis

Polymorphism and Dynamic Binding 14 - 14 Power. Point Presentation for Dennis, Wixom, &

Benefits of an Object Approach 14 - 15 Power. Point Presentation for Dennis, Wixom,

Unified Modeling Language – UML (Version 2) Defines a set of fourteen object diagramming techniques The key building block is the use case Diagrams are tightly integrated syntactically and conceptually to represent an integrated whole Application of UML can vary among organizations 14 - 16 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

UML 2. 0 Diagram Summary 14 - 17 Power. Point Presentation for Dennis, Wixom,

Integration of four UML Diagrams 14 - 18 Power. Point Presentation for Dennis, Wixom,

Adaptation of the Unified Process Phased Development Methodology 14 - 19 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

USE CASE DIAGRAM 14 - 20 Power. Point Presentation for Dennis, Wixom, & Roth

Use Case Diagram Concepts Summarizes all use cases (for the part of the system being modeled) together in one picture Typically drawn early in the SDLC Shows the associations between actors and use cases 14 - 21 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Use Case Diagram for Appointment System 14 - 22 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Syntax for Use Case Diagram 14 - 23 Power. Point Presentation for Dennis, Wixom,

Use Case Diagram for Specialized Actor 14 - 24 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Extends and Includes Associations 14 - 25 Power. Point Presentation for Dennis, Wixom, &

Steps in Creating the Use Case Diagram 1. Identify Use Cases 2. Draw the system boundary 3. Place Use Cases on the diagram Group Use Cases into packages Add special Use Case associations 4. Identify the actors 5. Add associations 14 - 26 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

CLASS DIAGRAM 14 - 27 Power. Point Presentation for Dennis, Wixom, & Roth Systems

Elements of a Class Diagram A static model that shows the classes and relationships among classes that remain constant in the system over time Resembles the ERD, but depicts classes which include both behaviors and states, while entities in the ERD include only attributes Scope not system wide, but pertaining to a single Use Case 14 - 28 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Class Diagram for Manage Appointment 14 - 29 Power. Point Presentation for Dennis, Wixom,

Class Diagram Syntax 14 - 30 Power. Point Presentation for Dennis, Wixom, & Roth

Operation Types Constructor operation: create new instances of a class Similar to relationships in ERDs Multiplicity shows how an instance of an object can be associated with other instances 14 - 31 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Multiplicity 14 - 32 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis

Steps in Creating a Class Diagram 1. Identify classes 2. Identify attributes and operations 3. Draw associations between classes 14 - 33 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Initial Attributes for Class Diagrams 14 - 34 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Revised Attributes and Associations 14 - 35 Power. Point Presentation for Dennis, Wixom, &

Final Class Diagram 14 - 36 Power. Point Presentation for Dennis, Wixom, & Roth

SEQUENCE DIAGRAM 14 - 37 Power. Point Presentation for Dennis, Wixom, & Roth Systems

Sequence Diagram Concepts Illustrates the classes that participate in a use case Shows the messages that pass between classes over time for one Use Can be a generic sequence diagram, but more frequently one is drawn for a single scenario within the use case Design diagrams are implementation specific -database objects or specific GUI components serve as classes 14 - 38 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Sequence Diagram 14 - 39 Power. Point Presentation for Dennis, Wixom, & Roth Systems

Steps in Creating a Sequence Diagram 1. Identify classes 2. Add messages 3. Place lifeline and focus of control 14 - 40 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Syntax for Sequence Diagram 14 - 41 Power. Point Presentation for Dennis, Wixom, &

Steps of the Customer Places Order Scenario 14 - 42 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.

Sequence Diagram for Customer Places Order Scenario 14 - 43 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

BEHAVIORAL STATE MACHINE DIAGRAM 14 - 44 Power. Point Presentation for Dennis, Wixom, &

Behavioral State Machine Concepts A dynamic model showing changes of state of a single class over time in response to events along with its responses and actions Typically not used for all classes, but just to help simplify the design of algorithms for methods of complex classes 14 - 45 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Behavioral State Machine Diagram for a Hospital Patient 14 - 46 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Behavioral State Machine Syntax 14 - 47 Power. Point Presentation for Dennis, Wixom, &

The Life of an Order 14 - 48 Power. Point Presentation for Dennis, Wixom,

Steps for Creating a Behavioral State Machine Diagram 1. Identify the states 2. Identify the transitions 14 - 49 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Behavioral State Machine Diagram for a Special Order 14 - 50 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Summary Many organizations are moving to the use of object-oriented techniques Objects are grouped into classes that share common properties and methods and arranged in a hierarchy Objects communicate by sending messages which trigger methods 14 - 51 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Summary Major object-oriented modeling techniques include: Use Case diagrams Class diagrams Sequence diagrams Statechart diagrams 14 - 52 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.

Copyright © 2009 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without the express written permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for redistribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages, caused by the use of these programs or from the use of the information contained herein. 14 - 53 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 4 th Edition Copyright 2009 © John Wiley & Sons, Inc. All rights reserved.