Model Driven Architecture

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Model Driven Architecture

• Secure Systems Group
• Patrick Morrison
• September 7, 2006

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MDA Definition

• Model Driven Architecture - The OMG approach for
  specifying system as models separate from their
  implementations, for specifying implementation,
  and for transforming models into implementations.
  This is based on a set of standards for
  describing business and application logic in a
  machine-readable, technology-independent way.
  The standards include MOF, UML, OCL, QVT and XMI.
  

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MDA Marketing

• These (MDA) specifications will lead the
  industry towards interoperable, reusable,
  portable software components and data models
  based on standard models. - MDA Guide Version
  1.01, www.omg.org/docs/03-06-01.pdf
• Model-driven engineering technologies offer a
  promising approach to address the inability of
  third-generation languages to alleviate the
  complexity of platforms and express domain
  concepts effectively. - Douglas C. Schmidt, in
  IEEE Computer, February 2006

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MDA A specialization of MDE
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MDE Concepts

• Models and Meta-Models
• Domain Specific Languages
• Transformations

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Models and Meta-Models

• Models give a high-level, problem-oriented view ,
  rather than a low-level, solution-oriented view
  of systems
• Meta-Models are used to describe Models in a
  precise, machine-translatable way

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Domain Specific Language (DSL)

• (Wikipedia) A programming language designed to
  be useful for a specific set of tasks. This is in
  contrast to general-purpose programming language
  (general-purpose language, GPL), for example Java
  or C, or general-purpose modeling languages like
  UML. Examples of DSLs include spreadsheet macros,
  YACC for parsing and compilers, Csound, a
  language used to create audio files, and
  GraphViz, a language used to define directed
  graphs, and create a visual representation of
  that graph.
• DSLs have also been called by various names
• Little languages
• Macros (in reference to the macro feature found
  in many applications)
• Application languages
• Very high level languages

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MDA Definitions

• MDA Model-driven architecture, a platform for
  abstracting system details in a machine-readable
  format 1
• Models and Meta-models
• CIM Computation Independent Model
• Domain Model business-level view
• PIM Platform Independent Model
• PSM Platform Specific Model
• UML-based (defined by MOF)
• Machine-readable (XMI)
• Documented standards

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MDA Definitions (2)

• UML Unified Modeling Language
• OCL Object Constrain Language
• MOF Meta Object Facility
• XMI - XML Metadata Interchange
• QVT Query, View, Transformation

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MOF A DSL for DSL's

• MOF can be viewed as a domain language for
  describing language
• OMG has used the MOF to define UML, a domain
  language for graphical modeling of systems
• This gives UML a precise, machine-readable and
  translatable definition, for which tool support
  can be provided
• The intent of MOF is to allow the precise
  definition of DSL's by its users

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The MDA (Meta-)Model Hierarchy
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From Models... to Models

• Query, View, Transformation (QVT)
• Takes a Model and a Mapping as inputs, produces a
  lower level model as output
• Example Given a CIM and a mapping to a PIM
  design model, a transformation produces a PIM
  design model for that CIM

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From Models to Artifacts (Code)

• With sufficiently detailed PSMs and Platform
  models, it is possible to generate code and
  configuration files for environments such as J2EE
  and .NET
• The OMG MDA specification doesn't have anything
  specific on this topic
• Other MDE systems use a variety of technologies,
  usually called 'model compilers' or 'generators'

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XMI XML Metadata Interchange

• (Wikipedia) The XML Metadata Interchange (XMI) is
  an OMG standard for exchanging metadata
  information via Extensible Markup Language (XML).
  It can be used for any metadata whose metamodel
  can be expressed in Meta-Object Facility (MOF).
  The most common use of XMI is as an interchange
  format for UML models, although it can also be
  used for serialization of models of other
  languages (metamodels).

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References
1 www.omg.org/mda 2 MDA Guide 1.0.1, 3
Meta Object Facility Specification,
http//www.omg.org/docs/formal/02-04-03.pdf 5
Model-Driven Engineering, Douglas C. Schmidt,
IEEE Computer, February 2006 6
http//www.voelter.de/data/articles/cgn.pdf
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Useful Links

• www.planetmde.org - site collecting links to
  MDE-related projects, people, books, papers,
  sites
• http//www.se-radio.net/ - Podcasts on software
  engineering, including MDSD