Unified Modeling Language

UML is primarily used for software development (in any industry or domain) UML is designed for use with many object-oriented software development methods, both today and for the methods when it was first developed – including OMT, Booch method, Objectory, and especially RUP, which it was originally intended to be used with when work began at Rational Software. Although originally intended for object-oriented design documentation, UML has been used effectively in other contexts such as modeling business process. As UML is not inherently linked to a particular programming language, it can be used for modeling a system independent of language. Some UML tools generate source code from a UML model. • Use case diagram for specifying user interactions with systems • Class diagram for specifying structures, including data structures • Activity diagram for specifying business process workflows • Component diagram for specifying how components interface with other components • Deployment diagram for specifying how components are deployed and executed on computational nodes In addition to syntactical (notational) elements with well-defined semantics, UML diagrams also allow for free-form comments (notes) that explain aspects such as usage, constraints, and intents. Sharing UML models can be exchanged among UML tools via the XML Metadata Interchange (XMI) format. Cardinality notation As with database Chen, Bachman, and ISO ER diagrams, class models are specified to use "look-across" cardinalities, even though several authors (Merise, Elmasri & Navathe, amongst others) prefer same-side or "look-here" for roles and both minimum and maximum cardinalities. Recent researchers (Feinerer and Dullea et al. including models, source code, scripts, executables, tables in database systems, development deliverables, a design documents, and email messages. MOF is designed as a four-layered architecture, as shown in the image at right. It provides a meta-meta model at the top, called the M3 layer. This M3-model is the language used by Meta-Object Facility to build metamodels, called M2-models. The most prominent example of a Layer 2 Meta-Object Facility model is the UML metamodel, which describes UML itself. These M2-models describe elements of the M1-layer, and thus M1-models. These would be, for example, models written in UML. The last layer is the M0-layer or data layer. It is used to describe runtime instances of the system. The metamodel can be extended using a mechanism called stereotyping. This has been criticized as being insufficient/untenable by Brian Henderson-Sellers and Cesar Gonzalez-Perez in "Uses and Abuses of the Stereotype Mechanism in UML 1.x and 2.0". ==Diagrams==

UML 2 defines many types of diagrams shown as a taxonomy in the image. Structure diagrams Structure diagrams emphasize the structure of the system using objects, classifiers, relationships, attributes and operations. They are used to document software architecture. • Class diagram Describes the structure of a class • Component diagram Describes how a software system is split into components and dependencies between the components • Composite structure diagram • Deployment diagram • Object diagram • Package diagram • Profile diagram Behavior diagrams Behavior diagrams emphasize the behavior of a system by showing collaborations among objects and changes to the internal states of objects. They are used to describe the functionality of a system. • Activity diagram Describes the business and operational activities of components • State machine diagram • Use case diagram Depicts of a user's interaction with a system Interaction diagrams Interaction diagrams, a subset of behavior diagrams, emphasize the flow of control and data between components of a system. • Communication diagram shows communication between components • Interaction overview diagram • Sequence diagram shows interactions arranged in time sequence; can be drawn via tools such as Lucidchart and Draw.io • Timing diagram focuses on timing constraints Examples Policy Admin Component Diagram.PNG |Component diagram BankAccount1.svg |Class diagram Activity conducting.svg |Activity diagram UML Use Case diagram.svg |Use case diagram Restaurant-UML-UC.png |Use case diagram UML Diagram Deployment.svg |Deployment diagram == Adoption ==

In 2013, UML had been marketed by OMG for many contexts, but aimed primarily at software development with limited success. It has been treated, at times, as a design silver bullet, which leads to problems. UML misuse includes overuse (designing every part of the system with it, which is unnecessary) and assuming that novices can design with it. It is considered a large language, with many constructs. Some people (including Jacobson) feel that UML's size hinders learning and therefore uptake. Visual Studio removed support for UML in 2016 due to lack of use. ==History==

UML has evolved since the second half of the 1990s and has its roots in the object-oriented programming methods developed in the late 1980s and early 1990s. The image shows a timeline of the history of UML and other object-oriented modeling methods and notation. Origin Rational Software hired James Rumbaugh from General Electric in 1994 and after that, the company became the source for two of the most popular object-oriented modeling approaches of the day: Rumbaugh's object-modeling technique (OMT) and Grady Booch's method. They were soon assisted in their efforts by Ivar Jacobson, the creator of the object-oriented software engineering (OOSE) method, who joined them at Rational in 1995. UML 1.x UML is originally based on the notations of the Booch method, the object-modeling technique (OMT), and object-oriented software engineering (OOSE), which were integrated into a single language. After the first release, a task force was formed The standards it produced (as well as the original standard) have been noted as being ambiguous and inconsistent. UML 2 UML 2.0 major revision replaced version 1.5 in 2005, which was developed with an enlarged consortium to improve the language further to reflect new experiences on the usage of its features. Although UML 2.1 was never released as a formal specification, versions 2.1.1 and 2.1.2 appeared in 2007, followed by UML 2.2 in February 2009. UML 2.3 was formally released in May 2010. UML 2.4.1 was formally released in August 2011. • UML Superstructure version 2.4.1 • UML Infrastructure version 2.4.1 • OCL version 2.3.1 • UML Diagram Interchange version 1.0. Since version 2.5, the UML Specification has been simplified (without Superstructure and Infrastructure), and the latest versions of these standards are now: • UML Specification 2.5.1 • OCL version 2.4 It continues to be updated and improved by the revision task force, who resolve any issues with the language. == See also ==