Chapter 5 - structural modelling

Structural model

Describes the structure of objects that supports the business processes or system

Static Structural model

Represents the system's structure at a specific point in time

Dynamic Structural model

Represents the system's behaviour over time

Basic elements of structural model

-Class

-Attributes

-Methods/operations

-Relationships

Types of methods/operations

-Constructor: creates an object

-Query: Makes information about the state of an object available

-Update: changes values of some or all of an object's attributes

-Destructor: deletes or removes an object

Types of relationships in a structural model

-Generalization

-Aggregation

-Association

-Composition

-Multiplicity

Aggregation relationship

A "whole-part" relationship where one class contains or is composed of other classes. Represents a "has-a" relationship

Association relationship

structural relationship indicating that one class is connected to or knows about another class. Represents any general connection between objects.

Composition relationship

stronger form of aggregation where the "part" cannot exist independently from the "whole."

Multiplicity relationship

Relationship that indicates how many of one class are related to another class

Object identification approaches

-Textual analysis

-Brainstorming

-Common object lists

-Patterns

Textual analysis

Reviews use case diagrams to identify objects. Nouns become classes and verbs become methods

Brainstorming

Facilitator leads a group to share ideas in comfortable setting then participants identify classes and attributes

Common object lists

A technique where analysts set aside use cases and instead identify objects based on the business domain

Patterns

relatively new area in OOSAD. Reusable tools for collaborating classes that provide solutions ot common problems

Class responsibility collaboration card

A brainstorming tool used in the design of object-oriented system and is most popular

Index cards

Used to document the responsibilities and collaborations of a class

Types of responsibilities in a class

Knowing responsibility and doing responsibility

Knowing responsibility

Things that an instance of a class must be capable of knowing

Doing responsibility

Things that an instance of a class must be capable of doing