MDA

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MDA

• gt Model Driven Architecture

gt Orçun Dayibas gt December, 2006 gt METU, Ankara
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Agenda

• Introduction
• What is MDA?
• Some Key Terms
• Development Life Cycle
• Meta-modeling Architecture
• Language for PIM
• Conclusion

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Hetereogenity in Software Development

• Programming Languages
• Java, C/C, C, COBOL, ADA, V. Basic, Eiffel,
  Smalltalk, ...
• Operating Systems
• Windows (3.1 -gt Vista), MacOS, Unix, Mobile
  (WinCE, PalmOS), Embedded, ...
• Networks
• Ethernet, IP, FireWire, USB, Bluetooth, HomeRF,
  ...
• There will be no consensus on below subjects
• Hardware
• Operating System
• Network Protocols
• Programming Languages

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Middleware solution

• Middleware is a software layer that masks
  hetereogentiy
• Placed between operating systems and application
  components.
• Middleware itself has various approaches
• CORBA
• COM / DCOM
• Java / EJB
• XML / SOAPNetworks
• No consensus again
• None of them will come out on top of others.
  Hence, the problem remains.
• Can we agree at a higher level?
• OMG says Yes!

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What is MDA? (1/2)

• Next level of abstraction model-based
  development

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What is MDA? (2/2)

• The Idea

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MDA in Practice

• Reduced cost and complexity of application
  development.
• Model-oriented implementation.
• Improved application quality and validation at
  model level.
• Constraint based, generated test cases.
• Reuse of business models
• Platform independence
• Rapid inclusion of emerging technologies
• Take a business model (off the shelf).
• Take a implementation model (off the shelf).
• Describe links between them.
• Generate the system.
• Available modelling products
• ArcStyler, iUML, OptimalJ, ...

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Basic Concepts of MDA

• Model
• A model is a formal specification of the
  function, structure and behavior of a system.
• Models of different systems are structured
  explicitly into
• Platform Independent Models (PIM)
• Platform Specific Models (PSM)
• PIM
• A formal specification of the structure and
  function of a system that abstracts away
  technical detail.
• PSM
• Specifies how the functionality specified in a
  PIM is realized on a particular platform.

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Developing in MDA(1/2)

• Create the PIM
• All MDA development projects start with the
  creation of a PIM.
• PIM at this level represents business
  functionality and behavior.
• Create and map the PSM
• After the first iteration, PIM is input to
  mapping which will produce PSM.
• PIM can be mapped either to a single platform or
  to multiple platforms

PIM
maps to
maps to
maps to

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Developing in MDA(2/2)

• Generating Application
• An MDA tool generates all or most of the
  implementation code for the deployment technology
  selected by the developer

PIM
maps to
maps to
maps to
PSMs

Implementations

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The Four-Layer Architecture of OMG(1/2)
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The Four-Layer Architecture of OMG(2/2)

• Beyond M3, M4?
• Yes, we could build a meta-model of M3, but the
  modeling language we use would itself be at M3.
  Hence, we do not need new M4.

MOF (class, attribute, association)
M3
UML, CWM (class, att., assoc., state, ...)
Application (classes, DB tables, ...)
Data of the Application (instances, table rows,
...)
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OMG Meta-modeling Architecture
Interchanging
Representation
XML
UML
By using
By using
Mapped by
MOF
XMI
Defined by
Specification
Standardized by
Meta-Model
CWM
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UML as a PIM Language

• UML
• Based on Object Orientation.
• Strong in modeling stractural aspects of the
  system.
• Weak in modeling behavioral parts.
• xUML (eXecutable UML)
• Plain UML AS (Action Semantics)
• Relays on state machine approach.
• State machine approach is suitable for specific
  domains (esp. embedded).
• The AS language is not a very high-level
  language.

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COSEML as a PIM Language

• Decomposition
• Based on Component Orientation.
• In each iteration converges to existent
  components.
• Weak in modeling behavioral parts.
• Over Specification
• Over-specification of the Component Orientation
  provides easier transformation for mapping PIM to
  PSM.
• Dynamic or behavioral parts of system
• COSEML needs some action semantics.

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Thank you, for your participation...
Orçun Dayibas
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References

• OMGs MDA An Architecture for Modeling
• Desmond DSouza
• MDA Distilled Principles of Model-Driven
  Architecture
• Stephen J. Mellor, Kendall Scott, Axel Uhl, Dirk
  Weise
• OMGs Model Driven Architecture
• Davide Buscaldi
• MDA Explained Practice and Promise
• Anneke Kleppe, Jos Warmer, Wim Bast
• Model-Driven Architecture Vision, Standards And
  Emerging Technologies
• John D. Poole

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