What is UML?

UML stands for Unified Modeling Language. The name itself tells us something about it and its history. It is a modeling language. This implies that it is a formal method of modeling programs. In practice, it can go beyond just the original modeling use though.

Areas where UML is effectively used;

UML has been used effectively in following areas

Enterprise information systems.

Banking and financial services.

Telecommunications.

Transportation.

Defense.

Retail.

Medical electronics.

Scientific.

Distributed Web-based services.

The UML can also be used to model nonsoftware systems, such as workflow in the legal system, a patient healthcare system, software engineering in aircraft combat systems, and the design of hardware.

Types of UML Diagrams

UML defines nine types of diagrams: class (package), object, use case, sequence, collaboration, statechart, activity, component, and deployment.

Class Diagrams

Class diagrams are the backbone of almost every object oriented method, including UML. They describe the static structure of a system.

Package Diagrams

Package diagrams are a subset of class diagrams, but developers sometimes treat them as a separate technique. Package diagrams organize elements of a system into related groups to minimize dependencies between packages.

Object Diagrams

Object diagrams describe the static structure of a system at a particular time. They can be used to test class diagrams for accuracy.

Use Case Diagrams

Use case diagrams model the functionality of system using actors and use cases.

Sequence Diagrams

Sequence diagrams describe interactions among classes in terms of an exchange of messages over time.

Collaboration Diagrams

Collaboration diagrams represent interactions between objects as a series of sequenced messages. Collaboration diagrams describe both the static structure and the dynamic behavior of a system.

Statechart Diagrams

Statechart diagrams describe the dynamic behavior of a system in response to external stimuli. Statechart diagrams are especially useful in modeling reactive objects whose states are triggered by specific events.

Activity Diagrams

Activity diagrams illustrate the dynamic nature of a system by modeling the flow of control from activity to activity. An activity represents an operation on some class in the system that results in a change in the state of the system. Typically, activity diagrams are used to model workflow or business processes and internal operation.

Component Diagrams

Component diagrams describe the organization of physical software components, including source code, run-time (binary) code, and executables.

Deployment Diagrams

Deployment diagrams depict the physical resources in a system, including nodes, components, and connections.