Modeling language

A modeling language is a notation for expressing data, information or knowledge or systems in a structure that is defined by a consistent set of rules.
A modeling language can be graphical or textual. A graphical modeling language uses a diagramming technique with named symbols that represent concepts and lines that connect the symbols and represent relationships and various other graphical notation to represent constraints. A textual modeling language may use standardized keywords accompanied by parameters or natural language terms and phrases to make computer-interpretable expressions. An example of a graphical modeling language and a corresponding textual modeling language is EXPRESS.
Not all modeling languages are executable, and for those that are, the use of them doesn't necessarily mean that programmers are no longer required. On the contrary, executable modeling languages are intended to amplify the productivity of skilled programmers, so that they can address more challenging problems, such as parallel computing and distributed systems.
A large number of modeling languages appear in the literature.

Type of modeling languages

Graphical types

Example of graphical modeling languages in the field of computer science, project management and systems engineering:

Behavior Trees are a formal, graphical modeling language used primarily in systems and software engineering. Commonly used to unambiguously represent the hundreds or even thousands of natural language requirements that are typically used to express the stakeholder needs for a large-scale software-integrated system.
Business Process Modeling Notation is an example of a Process Modeling language.
C-K theory consists of a modeling language for design processes.
DRAKON is a general-purpose algorithmic modeling language for specifying software-intensive systems, a schematic representation of an algorithm or a stepwise process, and a family of programming languages.
EXPRESS and EXPRESS-G is an international standard general-purpose data modeling language.
Extended Enterprise Modeling Language is commonly used for business process modeling across a number of layers.
Flowchart is a schematic representation of an algorithm or a stepwise process.
Fundamental Modeling Concepts modeling language for software-intensive systems.
IDEF is a family of modeling languages, which include IDEF0 for functional modeling, IDEF1X for information modeling, IDEF3 for business process modeling, IDEF4 for Object-Oriented Design and IDEF5 for modeling ontologies.
Jackson Structured Programming is a method for structured programming based on correspondences between data stream structure and program structure.
LePUS3 is an object-oriented visual Design Description Language and a formal specification language that is suitable primarily for modeling large object-oriented programs and design patterns.
Lifecycle Modeling Language is an open-standard language for systems engineering that supports the full system lifecycle: conceptual, utilization, support and retirement stages.
Object-Role Modeling in the field of software engineering is a method for conceptual modeling, and can be used as a tool for information and rules analysis.
Petri nets use variations on exactly one diagramming technique and topology, namely the bipartite graph. The simplicity of its basic user interface easily enabled extensive tool support over the years, particularly in the areas of model checking, graphically oriented simulation, and software verification.
Southbeach Notation is a visual modeling language used to describe situations in terms of agents that are considered useful or harmful from the modeler's perspective. The notation shows how the agents interact with each other and whether this interaction improves or worsens the situation.
Specification and Description Language is a specification language targeted at the unambiguous specification and description of the behavior of reactive and distributed systems.
SysML is a Domain-Specific Modeling language for systems engineering that is defined as a UML profile.
Unified Modeling Language is a general-purpose modeling language that is an industry standard for specifying software-intensive systems. UML 2.0, the current version, supports thirteen different diagram techniques, and has widespread tool support.
FLINT — language which allows a high-level description of normative systems.
Service-oriented modeling framework is a holistic language for designing enterprise and application level architecture models in the space of enterprise architecture, virtualization, service-oriented architecture, cloud computing, and more.
Architecture description language is a language used to describe and represent the systems architecture of a system.
Architecture Analysis & Design Language is a modeling language that supports early and repeated analyses of a system's architecture with respect to performance-critical properties through an extendable notation, a tool framework, and precisely defined semantics.

Examples of graphical modeling languages in other fields of science.

EAST-ADL is a Domain-Specific Modeling language dedicated to automotive system design.
Energy Systems Language, a language that aims to model ecological energetics & global economics.
IEC 61499 defines Domain-Specific Modeling language dedicated to distribute industrial process measurement and control systems.
Textual types

Information models can also be expressed in formalized natural languages, such as Gellish. Gellish has natural language variants such as Gellish Formal English and Gellish Formal Dutch, etc. Gellish Formal English is an information representation language or semantic modeling language that is defined in the Gellish English Dictionary-Taxonomy, which has the form of a Taxonomy-Ontology. Gellish Formal English is not only suitable to express knowledge, requirements and dictionaries, taxonomies and ontologies, but also information about individual things. All that information is expressed in one language and therefore it can all be integrated, independent of the question whether it is stored in central or distributed or in federated databases. Information models in Gellish Formal English consists of collections of Gellish Formal English expressions, that use natural language terms and formalized phrases. For example, a geographic information model might consist of a number of Gellish Formal English expressions, such as:
- the Eiffel tower Paris
- Paris city
whereas information requirements and knowledge can be expressed for example as follows:
- tower geographical area
- city geographical area
Such Gellish Formal English expressions use names of concepts and phrases that represent relation types that should be selected from the Gellish English Dictionary-Taxonomy. The Gellish English Dictionary-Taxonomy enables the creation of semantically rich information models, because the dictionary contains more than 600 standard relation types and contains definitions of more than 40000 concepts. An information model in Gellish can express facts or make statements, queries and answers.

More specific types

In the field of computer science recently more specific types of modeling languages have emerged.

Algebraic

are high-level programming languages for describing and solving high complexity problems for large scale mathematical computation. One particular advantage of AMLs like AIMMS, AMPL, GAMS, Gekko, Mosel, OPL, MiniZinc, and OptimJ is the similarity of its syntax to the mathematical notation of optimization problems. This allows for a very concise and readable definition of problems in the domain of optimization, which is supported by certain language elements like sets, indices, algebraic expressions, powerful sparse index and data handling variables, constraints with arbitrary names. The algebraic formulation of a model does not contain any hints how to process it.

Behavioral

Behavioral languages are designed to describe the observable behavior of complex systems consisting of components that
execute concurrently. These languages focus on the description of key concepts such as: concurrency, nondeterminism, synchronization, and communication. The semantic foundations of Behavioral languages are process calculus or process algebra.

Discipline-specific

A discipline-specific modeling language is focused on deliverables affiliated with a specific software development life cycle stage. Therefore, such language offers a distinct vocabulary, syntax, and notation for each stage, such as discovery, analysis, design, architecture, contraction, etc. For example, for the analysis phase of a project, the modeler employs specific analysis notation to deliver an analysis proposition diagram. During the design phase, however, logical design notation is used to depict the relationship between software entities. In addition, the discipline-specific modeling language best practices does not preclude practitioners from combining the various notations in a single diagram.

Domain-specific

is a software engineering methodology for designing and developing systems, most often IT systems such as computer software. It involves the systematic use of a graphical domain-specific language to represent the various facets of a system. DSM languages tend to support higher-level abstractions than General-purpose modeling languages, so they require less effort and fewer low-level details to specify a given system.

Framework-specific

A framework-specific modeling language is a kind of domain-specific modeling language which is designed for an object-oriented application framework. FSMLs define framework-provided abstractions as FSML concepts and decompose the abstractions into features. The features represent implementation steps or choices.
A FSML concept can be configured by selecting features and providing values for features. Such a concept configuration represents how the concept should be implemented in the code. In other words, concept configuration describes how the framework should be completed in order to create the implementation of the concept.