Analysis Using UML

Foundations

Object-Oriented Analysis (OOA)

Understanding a problem domain by modeling it as collaborating objects with responsibilities and relationships, before considering implementation.

Analysis vs. Design

Analysis focuses on understanding what the system must do in the problem domain; design decides how it will be built in the solution domain.

UML

The Unified Modeling Language, a standard visual notation for modeling structure and behavior of object-oriented systems.

Analysis Model

A model of the problem domain that captures key concepts, responsibilities, and relationships, free of implementation detail.

Domain Model

A representation of real-world concepts and their relationships in the problem area, used to ground analysis.

Requirements Input

Use Cases as Input

Use cases describe required behavior and drive analysis by revealing the objects and interactions needed to fulfill them.

Use Case Realization

Showing how a use case's behavior is achieved by collaborating analysis objects, often via interaction diagrams.

Glossary / Ubiquitous Language

A shared vocabulary of domain terms that keeps the analysis model consistent and understandable.

Finding Classes

Identifying Classes

Deriving candidate classes from domain nouns, use cases, and responsibilities that the system must handle.

Noun-Verb Analysis

A technique of examining requirement text where nouns suggest classes/attributes and verbs suggest operations and relationships.

Responsibilities

What a class must know and do; assigning responsibilities well is central to good analysis.

CRC Cards

Class-Responsibility-Collaborator cards used to explore classes and how they collaborate.

Boundary, Control, Entity

Analysis stereotypes: boundary objects interface with actors, control objects coordinate behavior, entity objects hold domain data.

Class Diagrams

Class Diagram

A UML diagram showing classes, attributes, operations, and relationships — the core of the analysis model's structure.

Attributes and Operations

The data a class holds (attributes) and the behavior it provides (operations).

Association

A structural link between classes, often with multiplicity and role names describing how instances relate.

Multiplicity

How many instances participate in an association (e.g., 1, 0..*, 1..*).

Aggregation and Composition

Whole-part relationships; composition implies the part's lifecycle depends on the whole, aggregation does not.

Generalization

An inheritance relationship where a subclass shares and specializes the features of a superclass.

Behavior

Sequence Diagram

An interaction diagram showing how objects collaborate over time via messages to realize a use case.

Communication Diagram

An interaction diagram emphasizing the relationships among objects as they exchange messages.

State Machine Diagram

A diagram showing the states of an object and transitions triggered by events, useful for objects with rich lifecycles.

Quality

Good Analysis Model

Clear, cohesive classes with well-assigned responsibilities, minimal coupling, and faithful representation of the domain.

From Analysis to Design

The analysis model provides a foundation that design refines with implementation decisions and technology concerns.