Chapter 6: Object Modeling

Attributes

characteristics that describe the object

O-O analysis

describes an IS by identifying things called objects; the end product of O-O analysis is an object model which represents the IS in terms of objects

Methods

specific tasks an object performs when it receives a message to do so

Message

an O-O command that tells an object to perform a certain method

Polymorphism

a message gives different meanings to different objects

Encapsulation

the idea that all data and methods are self-contained, as in a black box

Relationships

enable objects to communicate and interact as they perform business functions and transactions the system requires

Inheritance

enables an object to derive one or more of its attributes from another object (STRONGEST RELATIONSHIP)

Cardinality

describes how instances of one class relate to instances of another class

State transition diagram

shows how an object changes from one state to another, depending on events that affect the object; all possible states must be documented in it

Activity diagram

resembles a horizontal flowchart that shows the actions and events as they occur; shows the order in which the actions take place and identifies the outcomes

Use case

represents the steps in a specific business function or process in UML

What represents a business function

after objects, classes, and relationships have been identified, an object relationship diagram can be prepared to provide an overview of the system.

Subclasses

A further division of objects in a class. Subclasses are more specific categories within a class