Types of Models in Object Oriented Modeling and Design

Intention of object oriented modeling and design is to learn how to apply object -oriented concepts to all the stages of the software development life cycle.Object-oriented modeling and design is a way of thinking about problems using models organized around real world concepts. The fundamental construct is the object, which combines both data structure and behavior. Purpose of Models:

1. Testing a physical entity before building it
2. Communication with customers
3. Visualization
4. Reduction of complexity

Types of Models: There are 3 types of models in the object oriented modeling and design are: Class Model, State Model, and Interaction Model. These are explained as following below.

1. Class Model: The class model shows all the classes present in the system. The class model shows the attributes and the behavior associated with the objects. The class diagram is used to show the class model.The class diagram shows the class name followed by the attributes followed by the functions or the methods that are associated with the object of the class.Goal in constructing class model is to capture those concepts from the real world that are important to an application.


2. State Model: State model describes those aspects of objects concerned with time and the sequencing of operations – events that mark changes, states that define the context for events, and the organization of events and states.Actions and events in a state diagram become operations on objects in the class model. State diagram describes the state model.


3. Interaction Model: Interaction model is used to show the various interactions between objects, how the objects collaborate to achieve the behavior of the system as a whole. The following diagrams are used to show the interaction model:
   • Use Case Diagram
   • Sequence Diagram
   • Activity Diagram