Introduction to Model-driven Architecture

1. MDA
> Model Driven Architecture
> Orçun Dayıbaş
> December, 2006
> METU, Ankara

2. Agenda
> Introduction
> What is MDA?
> Some Key Terms
> Development Life Cycle
> Meta-modeling Architecture
> Language for PIM
> Conclusion
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3. Hetereogenity in
Software Development
> Programming Languages
Java, C/C++, C#, COBOL, ADA, V. Basic, Eiffel,
Smalltalk, ...
> Operating Systems
Windows (3.1 -> 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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4. 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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5. What is MDA? (1/2)
> Next level of abstraction; model-based development
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6. What is MDA? (2/2)
> The Idea
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7. 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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8. 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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9. 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
CORBA
Model
Java/EJB
Model … Other Model
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10. 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
CORBA
Model
Java/EJB
Model … Other Model
PSMs
CORBA
Imp.
Java/EJB
Imp. … Other Imp.
Implementations 10

11. The Four-Layer
Architecture of OMG(1/2)
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12. 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, ...) M2
Application
(classes, DB tables, ...) M1
Data of the Application M0
(instances, table rows, ...)
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13. OMG Meta-modeling
Architecture
Representation Interchanging
UML XML
By using By using
Mapped by
MOF XMI
Defined by
Specification
Standardized by
Meta-Model CWM
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14. 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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15. 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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16. Thank you...
Orçun Dayıbaş
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17. References
> OMG’s MDA An Architecture for Modeling
Desmond D’Souza
> MDA Distilled: Principles of Model-Driven
Architecture
Stephen J. Mellor, Kendall Scott, Axel Uhl, Dirk Weise
> OMG’s 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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