An object-oriented program is described by the interaction of these objects. Object-oriented design is a method of design encompassing the process of object-oriented decomposition and a notation for depicting both logical and physical as well as state and dynamic object oriented techniques pdf of the system under design. Both analysis and design can be performed incrementally, and the artifacts can be continuously grown instead of completely developed in one shot. A description of sequences of events that, taken together, lead to a system doing something useful.
Use case actors may be end users or other systems. In many circumstances use cases are further elaborated into use case diagrams. It is not mandatory to have this, but it helps to visualize the end-product and therefore helps the designer. A data model is an abstract model that describes how data is represented and used. However, it is possible to develop the relational data model and the object-oriented design artifacts in parallel, and the growth of an artifact can stimulate the refinement of other artifacts. The five basic concepts of object-oriented design are the implementation level features that are built into the programming language. A tight coupling or association of data structures with the methods or functions that act on the data.
Each object serves a separate function. It is defined by its properties, what it is and what it can do. An object can be part of a class, which is a set of objects that are similar. The ability to protect some components of the object from external entities.