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Chapter 5 - Domain Modeling Part 1

Chapter 5: Domain Modeling Part 1 – UML Class Diagram

Key Takeaway Points

  • Domain modeling aids in understanding the application domain.

  • Five Steps of Domain Modeling:

    • Collect information about the application domain.

    • Brainstorm ideas.

    • Classify brainstorming results.

    • Visualize using UML class diagrams.

    • Perform inspections and reviews.

Acquiring Requirements

  • Domain modeling contextualizes software architecture leading to use case derivation and allocation to iterations.

  • Involves understanding business goals, current situations, and preliminary requirements.

What Is a Model?

  • Conceptual representation of a system, useful for studying its properties.

Need for Models

  • Collective understanding among diverse team members.

  • Facilitates communication of perceptions and design ideas.

  • Essential during the maintenance phase for enhancements.

Domain Modeling

  • What: Process for understanding the application domain.

  • Why: Necessary due to varying backgrounds of software engineers impacting their understanding.

  • How: Collect information, brainstorming, classification, visualize via UML.

Domain Model

  • Defines application domain concepts via classes, attributes, and relationships.

  • Enhances understanding and communication among team members and stakeholders.

  • Acts as a basis for design, implementation, and maintenance.

Object-Oriented Paradigm

  • Views the real world as consisting of interacting objects.

Important Object-Oriented Concepts

  • Class: Abstraction of objects with similar properties and behaviors.

  • Attribute: Defines class properties.

  • Operation: Defines class behaviors.

  • Encapsulation: Instance of a class combining properties and behavior.

  • Information Hiding: Reducing the impact of changes on other program parts.

  • Polymorphism: One form taking multiple implementations.

UML Class Diagram

  • Structural representation of classes and their relationships, attributes, and operations.

  • Domain models are class diagrams excluding operations.

Inheritance Relationship

  • Generalization/specialization relationship illustrated as IS-A relation.

  • Example: A car is a vehicle (generalization of vehicle).

Object and Attribute Distinction

  • Objects exist independently; attributes require objects for context.

  • Attributes describe objects and store state without independent existence.

Inheritance Tests

  • IS-A Test: Each subclass instance is also an instance of the superclass.

  • Conformance Test: Superclass relationships apply to subclasses.

Aggregation Relationship

  • Represents part-of relationships between objects.

  • Example: Engine is part of a car.

Association Relationship

  • General relationships available in application.

  • Example: Instructor teaches a course.

Role and Multiplicity

  • Illustrates either role played by objects or the quantity involved in associations.

Summary: Relationships in UML Class Diagrams

  • Inheritance: IS-A relationship.

  • Aggregation: Part-of relationship.

  • Association: General relationships, direction indicated by arrows.

Sample Domain Model

  • Illustrates user attributes and admin management roles in a modeled system.

Applying Agile Principles

  • Collaborate with users for application understanding.

  • Simplify and expand domain models as necessary.