Unified Modeling Language (UML):-
UML, as the name implies, is a modeling language. It may be used to visualize, specify, construct, and
document the artifacts of a software system. It provides a set of notations (e.g. rectangles, lines, ellipses, etc.)
to create a visual model of the system. Like any other language, UML has its own syntax (symbols and sentence
formation rules) and semantics (meanings of symbols and sentences). Also, we should clearly understand that
UML is not a system design or development methodology, but can be used to document object-oriented and
analysis results obtained using some methodology.
UML Diagrams:
UML can be used to construct nine different types of diagrams to capture five different views of a system. Just
as a building can be modeled from several views (or perspectives) such as ventilation perspective, electrical
perspective, lighting perspective, heating perspective, etc.; the different UML diagrams provide different
perspectives of the software system to be developed and facilitate a comprehensive understanding of the
system. Such models can be refined to get the actual implementation of the system.
The UML diagrams can capture the following five views of a system:
Useƌ͛s ǀieǁ
Structural view
Behavioral view
Implementation view
Environmental view
User’s ǀieǁ: This view defines the functionalities (facilities) made available by the system to its users. The
useƌs͛ ǀieǁ Đaptuƌes the edžteƌŶal useƌ͛s ǀieǁ of the sLJsteŵ iŶ teƌŵs of the fuŶĐtioŶalities offeƌed ďLJ the
sLJsteŵ. The useƌ͛s ǀieǁ is a ďlaĐk-box view of the system where the internal structure, the dynamic behavior of different system components, the implementation etc. are not visible.
Structural view: The structural view defines the kinds of objects (classes) important to the understanding of
the working of a system and to its implementation. It also captures the relationships among the classes
(objects). The structural model is also called the static model, since the structure of a system does not change
with time.
Behavioral view: The behavioral view captures how objects interact with each other to realize the system
behavior. The system behavior captures the time-dependent (dynamic) behavior of the system.
Implementation view: This view captures the important components of the system and their dependencies.
Environmental view: This view models how the different components are implemented on different pieces of
hardware.
