1 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Model Transformations in Model-Based Systems Engineering Chris Paredis Associate Director Model-Based Systems Engineering Center Georgia Tech Model-Based Systems Engineering Center

2 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Objective u Provide enough information about model transformations so that you can envision where in your organization the use of model transformations can add value u Examples are not meant to be an exhaustive review of the state of the art but only illustrations

3 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Overview of Presentation u Background — Model Transformations –What is a model transformation? — some simple examples –Meta-modeling and Model transformations languages u Model Transformations in MBSE? –A taxonomy of usage scenarios –Examples and illustrations u How to get started? u Summary

4 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. What is a Model Transformation? u Model Transformation: Any operation on a model that produces another model u Very general: Almost anything you “do” with a model u Our primary interest: Automated model transformations

5 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Example: Models Evolve Over Time (from: A Practical Guide to SysML — Friedenthal, Moore, Steiner)

6 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Example: Models Evolve Over Time (from: A Practical Guide to SysML — Friedenthal, Moore, Steiner) We forgot to drain the residue…

7 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Example: Models Evolve Over Time (from: A Practical Guide to SysML — Friedenthal, Moore, Steiner) Hmm… we could make this a continuous process

8 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Model Transformations u A SysML model is a snapshot… u How are the snapshots connected to each other?  Model Transformations u A model transformation represents knowledge… u The more sophisticated the knowledge, the more difficult the transformation is to automate

9 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Examples of Model Transformations Transformation Source Model Stage-Gate Documents Transformation.pdf.html.pptx Endogenous TransformationExogenous Transformation

10 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Examples of Model Transformations Project Management Metrics Transformation Simulation & Optimization Transformation Source Model Stage-Gate Documents Transformation.pdf.html.pptx

11 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Some History: Model-Driven Architecture Platform- Independent Model CORBA Model MDA Tool generates all or most of the implementation code for deployment technology selected by the developer. Java/EJB Model CORBA XML/SOAP Model Java/EJB XML/SOAP Other Other Model Map Platform Specific Model to application interfaces, code, GUI descriptors, SQL queries, etc. (from: MDA, by R. Soley: PIM PSM Code

12 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Automated Transformations: A Closer Look… Transformation.pdf.html.pptx Source ModelTarget Model Source Modeling Language Target Modeling Language modeled in Models must be Formal

13 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Automated Transformations: A Closer Look… Transformation.pdf.html.pptx Source ModelTarget Model Source Modeling Language Target Modeling Language modeled in Source Meta-Model Target Meta-Model defined by conforms to Formal Syntax and Semantics

14 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Modeling Languages are also Modeled Formally u UML is defined by a meta-model u This meta-model is defined in a meta-modeling language: The MOF language (Meta-Object Facility) How is a meta-modeling language defined? Part of the meta-model for UML (from: A Practical Guide to SysML — Friedenthal, Moore, Steiner)

15 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. The OMG Meta-Model Infrastructure System conforms to represented by M0Reality Model M1User Model Meta-model M2UML Meta-meta-model M3MOF conforms to

16 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Model Transformation Specification conforms to readswrites refers to executes (Czarnecki, K., & Hellen, S., 2006) Source Meta-model Transformation Specification Target Meta-model Source Model Transformation Engine Target Model

17 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Implementations of Model Transformation u Imperative –Conventional programming tools –Access models through API of modeling tools –Java, Python, Ruby u Declarative –Consist of multiple declarative model transformation rules »Left-hand side = applicability pattern »Right-hand side = model modification to apply –Transformation engine automatically determines which rules to apply –ATL, QVT, Moflon, GReAT, VIATRA2,…

18 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Generative Model Transformation for Hydraulic System u Model Transformation rules to generate systems u Generate random system alternatives by applying rules in randomized order (Example in MOFLON)

19 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Generative Model Transformation for Hydraulic System u Model Transformation rules to generate systems u Generate random system alternatives by applying rules in randomized order (Example in MOFLON)

20 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Decision Tree of Generation Process

21 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Overview of Presentation u Context — Model Transformations –What is a model transformation? — some simple examples –Meta-modeling and Model transformations languages u How can model transformations be useful in MBSE? –A taxonomy of usage scenarios –Examples and illustrations u How to get started? u Summary

22 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Taxonomy for Model Transformations in MBSE u Organized by the nature of the knowledge encoded in the transformation 1.Knowledge about Views »Take information from a model and represent it in a different (graphical) syntax 2.Knowledge about Analysis »Take a structural description of a system and generate a corresponding analysis model 3.Knowledge about Synthesis »Generate a (more detailed) structural description u From simple to sophisticated From specific to general

23 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Why are Model Transformations Important? Collaboratively Developing Complex Systems Software Manufacturing Project Management Testing Analysis CAD Fuselage Landing Gear Engines …

24 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Why are Model Transformations Important? Highly Interrelated Information & Knowledge Software Manufacturing Project Management Testing Analysis CAD Fuselage Landing Gear Engines … Relations / Dependencies

25 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. System Model Why are Model Transformations Important? MBSE Allows for More Formal Communication Software Manufacturing Project Management Testing Analysis CAD Fuselage Landing Gear Engines …

26 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. System Model Why are Model Transformations Important? MBSE Allows for More Formal Communication Software Manufacturing Project Management Testing Analysis CAD Fuselage Landing Gear Engines …

27 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Example: Representing CAD parts in Creo as SysML Blocks in MagicDraw (from: Manas Bajaj, InterCAX)

28 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Example: Representing Assembly Structures in Windchill as SysML part properties in MagicDraw (from: Manas Bajaj, InterCAX) SysML model block structure Part structure (BOM) in PLM systems (e.g. Windchill) Auto-generation and sync

29 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Document Generator by INCOSE SE2 team (mbse.gfse.de)

30 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Document Generator by INCOSE SE2 team (mbse.gfse.de)

31 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Document Generator by INCOSE SE2 team (mbse.gfse.de) SysML + Profile Transformation DocBook XML file XSLT Transformation.html.pdf.docx

32 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Using DocGen at JPL (Source: “Model Based Document and Report Generation for Systems Engineering,” Delp, Lam, Fosse, Lee)

33 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Taxonomy for Model Transformations in MBSE u Organized by the nature of the knowledge encoded in the transformation 1.Knowledge about Views »Take information from a model and represent it in a different (graphical) syntax 2.Knowledge about Analysis »Take a structural description of a system and generate a corresponding analysis model 3.Knowledge about Synthesis »Generate a (more detailed) structural description u From simple to sophisticated From specific to general

34 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. System Model Why are Model Transformations Important? MBSE Allows for More Formal Communication Software Manufacturing Project Management Testing Analysis CAD Fuselage Landing Gear Engines …

35 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Execute Parametric Models in ModelCenter u Syntactic transformation from parametrics to ModelCenter Transformation System Properties Analysis Model

36 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. 36 SysML-Modelica Transformation Specification SysML- Modelica Transformation follows the principles of Model- Driven Architecture (MDA)

37 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. 37 Modelica SysML4Modelica Bi-directional Transformation

38 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. SysML4Modelica to Modelica Syntactical Mapping 38

39 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Transform Structure into Analysis Model

40 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Transform Structure into Analysis Model u Transformation requires deep analysis knowledge…

41 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Model Transformations for Fluid Power u Transformation Rules: –If Cylinder in descriptive, then ModelicaCylinder in analytical –If Pump in descriptive, then ModelicaPump and ModelicaFilter in analytical –… –If connection between Pump and Valve, then ModelicaConnection between ModelicaPump and ModelicaValve –… Not a good idea! Too many rules… Too specific, brittle Not a good idea! Too many rules… Too specific, brittle

42 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Define Model Correspondences Correspondence Models

43 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Structure to Analysis Mapping SysML4Modelica Analysis Model SysML Descriptive Model Transformation Modelica Model Only 2 rules One for components One for connections Only 2 rules One for components One for connections

44 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Generation of Vehicle Analyses (Work with students B. Bailey, J. Branscomb & Ford Motor Company) u Reference model of logical vehicle architecture in SysML u Specialize the reference model into a variant for a specific vehicle program u Specify the types of analyses needed

45 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Generation of Vehicle Analyses (Work with students B. Bailey, J. Branscomb & Ford Motor Company) u Automatically generate templates for: –Modelica (for physics-based modeling) –Simulink (for controls) u Subsystem modeling –SME fill in model details –Validate subsystem models u System-level model integration –Guaranteed compatibility –Modelica model integrated into Simulink Architecture in SysML Logical Vehicle Automated Transformation Integrated Simulink- Modelica Model

46 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Taxonomy for Model Transformations in MBSE u Organized by the nature of the knowledge encoded in the transformation 1.Knowledge about Views »Take information from a model and represent it in a different (graphical) syntax 2.Knowledge about Analysis »Take a structural description of a system and generate a corresponding analysis model 3.Knowledge about Synthesis »Generate a (more detailed) structural description u From simple to sophisticated From specific to general

47 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Synthesis Rules u Capture heuristic synthesis knowledge: What are promising system architectures? u Difficult to create a transparent “grammar” — which architectures are covered by the grammar?

48 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Additional Example of Synthesis Knowledge u Variant modeling — constraint-based representation of a set of architectures (mbse.gfse.de) u F6 program at JPL: Generation and analysis of fractionated satellite systems Transformation Set of variations One variant

49 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Architecture Exploration Using SysML & CPLEX (Work with former students Alek Kerzhner) 1.Formulate Problem in SysML 2.Transform to Superstructure 3.Transform to Introduce Behavior 4.Transform to Linearize 5.Transform to AIMMS syntax 6.Solve using CPLEX 7.Transform solutions into SysML SE Problem AIMMS – CPLEX Generation of Mixed Integer Programming model through transformations

50 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Overview of Presentation u Context — Model Transformations –What is a model transformation? — some simple examples –Meta-modeling and Model transformations languages u How can model transformations be useful in MBSE? –A taxonomy of usage scenarios –Examples and illustrations u How to get started? u Summary

51 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. How to get started.. u Imperative modeling –Traditional programming languages: Java, Python,… –Direct use of the APIs of SysML and Analysis tools u Declarative Model Transformation Languages –ATL, QVT, Moflon, VIATRA2,… –All are Eclipse based –Integration of Model Transformation tools into current SysML tools is not well supported…

52 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. Model Transformation Tools conforms to readswrites refers to executes (Czarnecki, K., & Hellen, S., 2006) Source Meta-model Transformation Specification Target Meta-model Source Model Transformation Engine Target Model Eclipse MMTSysML ToolAnalysis Tool

53 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. So What? Should I use Model Transformations? It depends… u Costs –Knowledge capture, management is expensive –Requires “knowledge engineers” who understand how best to generalize knowledge and encode it in transformations –Infrastructure u Benefits –Improved consistency –Once the knowledge has been captured, the cost of applying it is very small –Eliminate tedious, non-value-added tasks in MBSE process

54 MBSE 2012 Copyright © Chris Paredis. All Rights Reserved. 1.Model Transformations –Any operation on a model that produces another model –Automated model transformations defined at meta-model level –Model transformation tools in Eclipse 2.Model Transformations in MBSE –Views: Synchronize views and maintain consistency –Analysis: Generate analysis models –Synthesis: Generate promising architectures 3.Cost-Benefit –Identify simple MBSE tasks that are tedious and error-prone Model-Based Systems Engineering Center Key Take-Aways

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