Unified Modelling Language

Unified Modeling Language (UML) is a modelling language for software engineering.

UML has been adopted as a standard by the Object Management Group (OMG) and International Standard Organization (ISO).

Object Contraint Language (OCL) defines the rules for model elements.

In its latest version as of 2023, UML 2.5 consist of two elements:

UML Specification 2.5
OCL 2.4

List of UML Diagram Types

Non-exhaustive list of UML diagram types:

Structural
- Class
Behavioral
- General
  - Activity
  - Use case
- Interaction
  - Sequence
  - Communication
  - Interaction overview
  - Timing

Structural

Class Diagram

Considering object-oriented programming, a class diagram displays classes within a software project and the relationships between them.

Optionally, class diagrams may include attributes and methods.

Behavioral

General behavioral Diagrams

I define general behavioral diagrams that does not belong to any specific subset of behavioral diagrams

Use Case Diagram

Use Case diagram is a graphical depiction of a user’s possible interactions with a system.

It is usually done at the earliest stages of design.

Activity Diagram

An activity diagram represents a workflow.

It represents the actions. It does not represent the actor or agent performing the action.

A merge node is a control node that brings together multiple incoming alternate flows to accept single outgoing flow. There is no joining of tokens. Merge should not be used to synchronize concurrent flows.

A join node is a control node that has multiple incoming edges and one outgoing edge and is used to synchronize incoming concurrent flows. Join nodes are introduced to support parallelism in activities.

A swimlane diagram would be an activity diagram where the processes and decisions can be grouped in lanes.

Interaction Diagrams

Interaction diagrams are a subset of behavioral diagrams.

Sequence diagram

A sequence diagram displays the actors and the actions taken by them.

Communication diagrams

A communication diagram combines information present in Class, Sequence, and Use Case diagrams.

External references

Wikipedia; “Unified Modelling Language“; Wikipedia