Unified Modeling Language (UML) Overview

Unified Modeling Language (UML)

• UML is a standard visual modeling language.
• UML models software architecture, design, and implementation of complex systems both structurally and behaviorally.
• UML is the most important industry-standard language for specifying, visualizing, constructing, and documenting software systems.
• Three existing practices contributed to the development of UML: the Booch Method, Object-Modeling Technique (OMT), and Objectory.
• The Object Management Group (OMG) oversees the definition and maintenance of the UML specifications.
• UML enables engineers and programmers to use one language across all phases of the software development lifecycle.

Modeling Concepts Specified by UML

• Functional
  • Uses use case diagrams to represent system functionality from a user's perspective.
• Object
  • Uses class diagrams to represent system structure in terms of objects, attributes, associations, and operations.
• Dynamic
  • Uses interaction diagrams, state machine diagrams, and activity diagrams to describe a system's internal behavior.

Types of UML Diagrams

• Structural UML Diagrams
  • Class diagram: Describes the static structure of a system.
  • Package diagram: Used as a subset of a class diagram to organize elements of a system.
  • Object diagram: Describes the static structure of a system at a particular time.
  • Component diagram: Describes the organization of physical software components like source codes, run-time code, and executables.
  • Composite structure diagram: Shows the internal parts of a class.
  • Deployment diagram: Depicts the physical resources in a system, including nodes, components, and connections.
• Behavioral UML Diagrams
  • Activity diagram: Illustrates the dynamic nature of a system by modeling the flow of control from activity to activity.
  • Communication diagram: Describes interactions among classes in terms of message exchanges over time.
  • Use case diagram: Models the functionalities of a system using actors and use cases.
  • State machine diagram: Describes dynamic behavior of a system in response to external stimuli.
  • Sequence diagram: Models interactions among objects in sequence.
  • Interaction overview diagram: Combines an activity diagram with a sequence diagram to model complex interactions.
  • Timing diagram: Focuses on processes taking place during a specific period of time, with time increasing from left to right.

Architecture Description Language (ADL)

Element Types in Business Process Diagrams

• Swimlanes: Show who is responsible for each step
  • Pool: Represents major participants in a process. Different pools may be in different companies or departments.
  • Lane: A sub-part of a pool. Shows activities and flow for a certain role or participant, defining accountability within the processes.
• Artifacts: Add extra details
  • Data object: Shows the necessary data for an activity.
  • Group: Shows a logical grouping of activities, but does not change the diagram's flow.
  • Annotation: Provides further explanation to a part of the diagram.

Sub-Models Within A BPMN Diagram

• Private BP: Involves internal processes specific to an organization and do not cross organizational boundaries.
• Abstract BP: Occurs between a private BP and an external participant or process.
• Collaborative BP: Shows interactions between two or more business entities.