Ontologies Reasoning Components Agents Simulations An Overview of Model-Driven Engineering and Architecture Jacques Robin

Outline  What is MDA?  MDA Principles  MDA Process and Software Reuse  OMG MDA standards  Third party providers roles, standards and tools

What is Model-Driven Architecture (MDA)?  An initiative from the Object Management Group (OMG) started in 1997,  New paradigm of software development  Goals:  Maxime software reuse across platforms  Solve the second order interoperability problem among different middleware (which goal was to solve the first order interoperability problem among programming languages)  Raise the level of abstraction where most development effort is spent from code to model  Provide standards to automate the entire software development process through a model transformation approach  Reuses and extends previous standards  Unified Modeling Language (UML), by OMG  Meta-Object Facility (MOF), by OMG  eXtensible Markup Language (XML), by W3C (World-Wide Web Consortium,

MDA Principles  The most valuable, durable, reusable assets produced during the development process is not code but models  Far more significant and cost-effective quality gains are achievable by improving design and models than by improving code  Benefits from careful, detailed, explicit modeling is not limited to the application under development but extend to all the processes, artifacts, languages, tools and platforms used for this development

MDA Principles  A high degree of software process automation can be achieved by:  Building a variety of models, each one with a different role in the process,  Making each of these models machine processable by expressing it in a semi-formal notation devoid of natural language  Defining this notation itself as an object-oriented model (called a meta- model)  Storing all models and meta-models with traceability links in a repository accessible to model manipulation software  Abstracting generic transformations between pairs of meta-models that computationally codify the know how for one software process stage  Using model transformation engines to apply these transformations to the source model of a process stage and generate the target model of that stage  Define meta-models for the meta-modeling and model transformation notations

Abstraction Executability Current Mainstream OOSE Domain Modeling w/ UML or DSML CASE Tool Domain/ Business Model: UML or DSML + Feature Tables + NL Specification Model: (UML or DSML) + NL Requirement Analysis w/ UML or DSML CASE Tool High-Level Design Model: (UML or DSML) + NL High-Level Design Detail Design (Refinement) simultaneously with Programming (Translation) with Execution Platform IDE Source Code Executable Code Source Code to Executable Code Translation

Abstraction Executability Manual MDE: Extreme Modeling Fully Refined Specification Platform Independent Model (PIM): UML/OCL or DSPIML Fully Refined Requirement Analysis w/ UML/OCL or DSPIML CASE Tool High-Level Realization PIM: UML/OCL or DSPIML High-Level Design w/ UML/OCL or DSPIML CASE Tool PSM MetaModel and/or UML Profile Platform Specific Model (PSM) Metamodeling and/or Profiling Fully Refined Realization PIM: UML/OCL or DSPIML Design Full Refinement w/ UML/OCL or DSPIML CASE Tool PSM: Profiled UML/OCL or DSPSML PIM to PSM Translation Source Code PSM to Source Code Translation PIM MetaModel and/or UML Profile Platform Independent Model (PIM) Metamodeling and/or Profiling Executable Code Source Code to Executable Code Translation

Abstraction Executability Transformation Based MDE: UML Programming Fully Refined Specification Platform Independent Model (PIM): UML/OCL or DSPIML Fully Refined Requirement Analysis w/ UML/OCL or DSPIML CASE Tool High-Level Realization PIM: UML/OCL or DSPIML High-Level Design w/ UML/OCL or DSPIML CASE Tool Fully Refined Realization PIM: UML/OCL or DSPIML Design Full Refinement w/ UML/OCL or DSPIML CASE Tool PSM: Profiled UML/OCL or DSPSML PIM to PSM Translation Source Code PSM to Source Code Translation Executable Code Source Code to Executable Code Translation PSM to Source Code Translation Transformation Base PSM to Source Code Translation Transformation Development PIM to PSM Translation Transformation Base PIM to PSM Translation Transformation Development Realization PIM Refinement Transformation Base Realization PIM Refinement Transformation Development High-Level Realization PIM Transformation Base High-Level Realization PIM Transformation Development

MDA Software Process Application Requirement Model Domain Computation Independent Model Requirement Meta-model Application Platform Independent Model CIM Meta-model PIM Meta-model Meta- Meta-Model Platform Model Platform Meta-model PSM Meta-model Application Platform Specific Model Application Source Code Source Code Meta-Model Testing Model Testing Code Meta-Model Testing Meta-model Testing Code Textual Meta- Meta-Model

Artifact Reuse with MDA Process Domain Computation Independent Model Application A Requirement Model Application A Platform Independent Model Platform P Model Application A Platform P Specific Model Application B Platform Independent Model Application B Requirement Model Application B Platform P Specific Model Platform Q Model Application A Platform Q Specific Model Application B Platform Q Specific Model Testing Model AP Testing Model AQ Testing Model BP Testing Model BQ

Automated MDA Process: Design Model Transformation Engine Requirement Meta-model CIM Meta-model PIM Meta-model Design Transformations Model Transformation Meta-model Application Requirement Model Domain Computation Independent Model Application Platform Independent Model

Automated MDA Process: Implementation Model Transformation Engine PIM Meta-model Model Transformation Meta-model Application Platform Independent Model PIM  PSM Transformations Platform Model Platform Meta-model PSM Meta-model Application Platform Specific Model

Automated MDA Process: Code Generation Model Transformation Engine Model Transformation Meta-model PSM Meta-model Application Platform Specific Model Code Generation Transformations Source Code Meta-Model Application Source Code

Automated MDA Process: Test Generation Model Transformation Engine Model Transformation Meta-model PSM Meta-model Application Platform Specific Model Requirement Meta-model Application Requirement Model Test Generation Transformations Testing Model Testing Meta-model

Automated MDA Process: Reverse Engineering Model Transformation Engine PIM Meta-model Model Transformation Meta-model Application Platform Independent Model PSM  PIM Reverse Engineering Transformations Platform Model Platform Meta-model PSM Meta-model Application Platform Specific Model

Automated MDA Process: PIM Refactoring Model Transformation Engine Model Transformation Meta-model PIM Refactoring Transformations PIM Meta-model Refactored PIM Meta-model Legacy PIM

Automated MDA Process: PSM Refactoring Model Transformation Engine Model Transformation Meta-model PSM Refactoring Transformations PSM Meta-model Refactored PSM Meta-model Legacy PSM

Automated MDA Process: Code Refactoring Model Transformation Engine Model Transformation Meta-model Code Refactoring Transformations Source Code Meta-Model Refactored Source Code Legacy Source Code Source Code Meta-Model

OMG Tasks in MDA Initiative  Define meta-modeling standard: Meta-Object Facility (MOF)  Define general-purpose visual modeling standard: Unified Modeling Language (UML)  Define complementary general-purpose, semi-formal textual modeling standard to make both MOF metamodels and UML models more precise and devoid of natural language: Object Constraint Language (OCL)  Define general-purpose, both machine-processable and user- readable persistent textual format for both MOF meta-models and UML models: XML Model Interchange (XMI)  Define model manipulation standard: Query View Transform (QVT)  Each of these standards to be defined in terms of:  Abstract syntax as a MOF meta-model  Concrete syntax (visual or textual)  Formal semantics (very partial up to now)

Relationships between OMG’s MDA standards... UML2 Infrastructure Classes Attributes Types Packages... Basic Associations... Constructs... UML2 Superstructure Activities Actions States Transitions... Behavioral Components Ports... Structural QVT MOF2 EMOFCMOFOCL merge XMI merge DI merge UML2 RAPI

Example Meta-Model system +name actor +name useCase +title * * extends includes OrderItem ValidateCart e-Store UML Model: Use-Case Diagram MOF Meta-Model of Use-Cases 1..* extends

Example Meta-Meta-Model system +name actor +name useCase +title 1.. * * extends includes MOF Meta-Model of UML Use-Cases MOF Meta-Model of MOF Meta-Model attribute +name +multi parameter +direction operation +name class +name associationEnd +name +multi association +name package +name extends 1..*

Example of XMI Encoding system +name * orderItem validateCart 0..* extends includes useCase +title e-Store 0..1 actor +name “orderItem” “validateCart” “Client” “e-Store” Client

Other Stakeholders’ Tasks in MDA Initiative  Platform providers:  Define platform model as UML Profile or PSM meta-model in MOF  Multiple domains or wide domain application providers:  Use only standards defined by OMG and platform providers  Narrow domain application providers:  Define special-purpose modeling languages in MOF  MDA CASE tool providers:  Implement model base development and management services such as edition, syntactic validation, import, export, persistence, query, access control, versioning and traceability for:  Models in UML, OCL and MOF-specified user-defined languages  MOF meta-models  QVT and MOF-specified model transformation languages  Define APIs to program new model processing services on top of theses basic services  Implement model transformation engines based on MOF and QVT  Implement code and test generation services from PSM

MDA Third-Party Standards and Tools  Java Modeling Interface (JMI):  Standard from Java Community Process (JCP)  Defines a set of Java interfaces to process models represented as Java objects:  Reflective interfaces define general model manipulation operations that are independent of the model’s meta-model  Taylored interfaces define model manipulation operations that are specific to models that follow a given meta-model  Taylored interfaces can be automatically generated from a MOF meta-model  Eclipse Modeling Framework (EMF):  Standard from the Open Source Java-Based IDE project Eclipse (  Plug-in for Eclipse IDE framework  Implements similar reflective and taylored interfaces than JMI  Implements generation of taylored interface from MOF meta-model  Implements generation of Eclipse-integrated model editor from MOF meta-model

Model representation as XML document and Java Objects Model Meta-model MOF Meta-model (meta-meta-model) File SystemMain Memory XML Document XML Schema XMI Schema textually represents Java Objects Java Taylored Interfaces Java Reflective Interfaces programmatically represents programmatically represents import / export generates create / process

Java Model Representation vs. Implementation  Java objects generated using the taylored and reflective interfaces of JMI or EMF merely represent model elements  They only provide a handle to process these elements using Java  They are completely different from Java objects that implement these model elements  Though among many other uses, theses model representation Java objects can be used as input to program in Java the generation of model implementing Java objects  But they could also be used to generate a C++ or Prolog implementation of the application or any other MDA service  Java model representation objects are useful for MDA CASE tools during the development process of an application, whereas Java model implementation objects are useful for this application  In one case, Java is used to implement CASE tools functionalities, in the second case, Java is used to implement application functionalities