Subject: Object Oriented Modeling and Design

Difficulty: Medium

Marks: 4 Marks

Following are the three models of UML:

Three models of OO methodology:

• Class Model
• State Model
• Interaction Model

1. Class Model:

• The class model describes the structure of objects in a system, their identity, their relationships to other objects, their attributes and their operations.

• The class model provides context for the state and interaction models.

2. State Model:

• The state model describes those aspects of objects concerned with time and the sequencing of operations also events that mark changes, states that define the context for the events, and the organization of events and states.

• The state model captures control, the aspect of a system that describes the sequences of operations that occur, without regard for what the operations do, what they operate on, or how they are implemented.

3. Interaction Model:

• The interaction model describes interaction between objects i.e. how individual objects collaborate to achieve the behavior of the system as a whole.

• The state and interaction models describe different aspects of behavior. Use cases, sequence diagrams and activity diagrams document the interaction model. Use cases document major themes for interaction between the system and outside actors.