Introduction to UML

What is UML? UML stands for “Unified Modeling Language”. It is an industry-standard graphical language for analysing, describing and documenting the artifacts of an object-oriented system under development. The UML uses mostly graphical notations to express the OO analysis and design of software projects.  Simplifies the complex process of software design.

Why UML for Modeling Use graphical notation to communicate more clearly than natural language (imprecise) and code (too detailed). Help acquire an overall view of a system. UML is not dependent on any one language or technology. UML moves us from fragmentation to standardization.

History of the UML In 1990s, many different methodologies, along with their own set of notations, were introduced to the market Object Modeling Technique (OMT) (James Rumbaugh) Booch (Grady Booch) Object-oriented software engineering (OOSE) (Ivar Jacobson)

History of the UML

UML Diagrams Behavioral diagrams : It affects how the states of objects change over time Use case diagram Sequence diagram Collaboration diagram Activity diagram State diagram Structural diagrams: show the structure of a system Class diagram Object diagram Component diagram Package diagram Deployment diagram

Use Case Diagram A use case is a description of some way in which a system or a business is used, by its customers, users or by other systems. Mainly used for capturing user requirements (describing a set of user scenarios). Work like a contract between end user and software developers. A use case diagram shows how system use cases are related to each other and how the users can get at them.

Use Case Diagram

Sequence Diagram Sequence diagrams are used to represent the flow of messages, events and actions between the objects or components of a system. The horizontal dimension shows the objects participating(Interaction Partners) in the interaction. The vertical arrangement the messages indicates their order.

Sequence Diagram

Communication Diagram A communication diagram, formerly called a collaboration diagram, is an interaction diagram that shows similar information to sequence diagrams but its primary focus is on object relationships. On communication diagrams, objects are shown with association connectors between them. Messages are added to the associations and show as short arrows pointing in the direction of the message flow. The sequence of messages is shown through a numbering scheme.

Communication Diagram

Activity Diagram Activity Diagrams are a type of flowchart used to describe a business process or workflow of a system; that is, they show the flow of control from activity to activity in the system, what activities can be done in parallel, and any alternate paths through the flow. They support parallel tasks, which a pure flowchart can’t handle.

Activity Diagram

State Diagram State diagrams show the sequences of states an object goes through during its life cycle.

Class Diagram Used for describing structure and behavior in the use cases. Provide a conceptual model of the system in terms of entities and their relationships. Used for requirement capture, end-user interaction. Detailed class diagrams are used for developers.

Class diagram

Object Diagram

Component Diagram Component diagrams illustrate the pieces of software that will make up a system. A component diagram has a higher level of abstraction than a class diagram – usually a component is implemented by one or more classes (or objects). They are the building blocks so a component can eventually encompass a large portion of a system.

Component Diagram

Package Diagram Logical grouping of UML elements. Simplifies UML diagrams Groups related elements into a single higher-level element. Dependency relationships Shows a dependency between packages.

Package Diagram

Deployment Diagram A deployment diagram models the run-time architecture of a system. It shows the configuration of the hardware elements (nodes) and shows how software elements are mapped onto those nodes. The diagram shows how the finished system will be deployed on one or more machines.

Deployment Diagram

UML Modeling Tools Enterprise Architect. Rational Rose. Microsoft Office Visio. Edraw UML Diagram.