Metamodeling

This is the concept of metamodeling in computer science and related disciplines. For the language patterns known as the Meta-model in Neuro-linguistic programming see Meta model (NLP).

In computer science and related disciplines, metamodeling is the construction of a collection of "concepts" (things, terms, etc.) within a certain domain. A model is an abstraction of phenomena in the real world, and a metamodel is yet another abstraction, highlighting properties of the model itself. This model is said to conform to its metamodel like a program conforms to the grammar of the programming language in which it is written. Common uses for metamodels are:

As a schema for semantic data that needs to be exchanged or stored
As a language that supports a particular method or process
As a language to express additional semantics of existing information

Definition

The following discussion can be viewed as a detailed application of metamodeling techniques, related to Model Driven Engineering. In software engineering, data engineering and software engineering, the use of models is more and more recommended. This should be contrasted with the classical code-based development techniques. A model always conforms to a unique metamodel. One of the currently most active branch of Model Driven Engineering is the approach named model-driven architecture proposed by OMG. This approach is based on the utilization of a language to write metamodels called the Meta Object Facility or MOF. Typical metamodels proposed by OMG are UML, SysML, SPEM or CWM. All the languages presented below could be defined as MOF metamodels.

Types of meta-models

For software engineering, several types of models (and their corresponding modeling activities) can be distinguished:

Meta-Data Modeling (MetaData Model)
Meta-Process Modeling (MetaProcess Model)
Model Transformation Language (see below)

Zoos of metamodels. A library of similar meta-models has been called a Zoo of meta-models in paper. Several meta-model zoos may be found at: AtlanticZoo. Some are expressed in ECore. Others are written in MOF 1.4 - XMI 1.2. The metamodels expressed in UML-XMI1.2 may be uploaded in Poseidon, a UML CASE tool.

Model Transformations

One important move in Model Driven Engineering is the systematic use of Model Transformation Languages. The OMG has proposed a standard for this called QVT for Queries/Views/Transformations. QVT is based on the Meta-Object Facility or MOF. Among many other Model Transformation Languages (MTLs), some examples of implementations of this standard are AndroMDA, VIATRA, Tefkat or MT.

QVT (Transformation Model). In the case of MOF/QVT, a model transformation is also a model. This means that the transformation language should be defined by a precise meta-model. An example of a model transformation language based on a precise meta-model is ATL.

Relationship to ontologies

Meta-models are closely related to ontologies. Both are often used to describe and analyze the relations between concepts ^*.

Ontologies express something meaningful within a specified universe of discourse by utilizing a grammar for using vocabulary. The grammar specifies what it means to be a well-formed statement, assertion, query, etc. (formal constraints) on how terms in the ontology’s controlled vocabulary can be used together. ^*

Meta-modeling can be considered as an explicit description (constructs and rules) of how a domain-specific model is built. In particular, this comprises a formalized specification of the domain-specific notations. Typically, metamodels are – and always should – follow a strict rule set. “A valid metamodel is an ontology, but not all ontology are modeled explicitly as metamodels” [Metamodel-b.

References

^* Booch, G., Rumbaugh, J., Jacobson, I. (1999). The Unified Modeling Language User Guide. Redwood City, CA: Addison Wesley Longman Publishing Co., Inc.
^* J. P. van Gigch. System Design Modeling and Metamodeling. Plenum Press, New York, 1991
^* J. Bezivin. On the Unification Power of Models. Software and System Modeling (SoSym) 4(2):171--188. http://www.sciences.univ-nantes.fr/lina/atl/www/papers/OnTheUnificationPowerOfModels.pdf
^* What is meta-modeling? http://www.metamodel.com/staticpages/index.php?page=20021010231056977 . 11.10.2002
^* Johannes Ernst. What are the differences between a vocabulary, a taxonomy, a thesaurus, an ontology, and a meta-model? http://www.metamodel.com/article.php?story=20030115211223271 . 10.10.2002
^* E. Söderström, B. Andersson, P. Johannesson, E. Perjons, and B. Wangler. Towards a Framework for Comparing Process Modelling Languages. Lecture Notes In Computer Science; Vol. 2348. Proceedings of the 14th International Conference on Advanced Information Systems Engineering. Pages: 600 – 611, 2002

Software engineering | Systems engineering

Métamodèle

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Definition

Types of meta-models

Model Transformations

Relationship to ontologies

See also

References