1. Reusing Modeling Elements in IV&V Thomas Otani Naval Postgraduate School 2009 NASA Independent Verification and Validation (IVV) Annual Workshop John Ryan Reuse Working Group Lead

2. Outline The IV&V Reuse Working Group The System Reference Model (SRM) Reuse in SRM Reusable Modeling Elements SRM Reuse Framework Intermediate Reuse Repository Conclusion 2009 IVV Annual Workshop2Sept 15 - Reusing Modeling Elements

3. The Reuse Working Group Objectives Provide reusable modeling artifacts to support in NASA IVV efforts to:  Reduce labor cost and time of product deliverables  Reduce duplication of modeling artifacts  Increase scope, flexibility, and responsiveness  Leverage previous understandings of systems and behaviors 2009 IVV Annual Workshop3Sept 15 - Reusing Modeling Elements

4. The Reuse Working Group Previous Goals Define the definition and attributes of reuse and use artifacts Define how reuse integrates with the product lines Define the process and requirements for a Reuse Repository Current Goals To demonstrate the feasibility and value of reuse through focused projects To increase the supply and availability of reusable artifacts To increase community capability and interest to leverage existing artifacts 2009 IVV Annual Workshop4Sept 15 - Reusing Modeling Elements

5. The Reuse Working Group Scope The WG will define and recommend areas within modeling, validation, and verification activities for reuse, and will provide support (analytical, development, management, and training) to enable reuse within those activities across projects. Focus on: Reuse of existing artifacts Reuse of newly developed artifacts derived from existing artifacts Developing initial modeling, assertion, and report templates Reuse of modeling artifacts (Initially) Reuse for science and exploration mission projects 2009 IVV Annual Workshop5Sept 15 - Reusing Modeling Elements

6. System Reference Model We advocate the use of System Reference Model (SRM) for the IV&V team to capture its understanding of the problem domain The SRM contains Written Use Cases UML artifacts and a set of formal assertions and accompanying test scenarios to model precisely the required behavior of the system 2009 IVV Annual Workshop6Sept 15 - Reusing Modeling Elements

7. Executable SRM We advocate that the SRM be executable for it to be truly useful Executable SRM includes a computer-aided tool to validate behavior specifications Software automation is the key to the successful validation (and verification) of the behaviors of complex systems Traditional manual process is woefully inadequate in locating subtle errors in increasingly complex software-intensive systems of systems 2009 IVV Annual Workshop7Sept 15 - Reusing Modeling Elements

8. Reuse in SRM Two types of reuse in SRM: Adoption Reuse  An existing artifact (e.g. activity diagram) is reused in another product Instantiation Reuse  A concrete artifact is created from a generic template An idea of generic assertion template was presented at IEEE SSIRI 2008 2009 IVV Annual Workshop8Sept 15 - Reusing Modeling Elements

9. Sample Assertion Template Resusing Modeling ElementsSept 15 - IVV Annual Workshop9

10. Test Scenario Patterns These are the types of test patterns that must accompany every assertion Obvious Success Obvious Failure Event Repetitions Time-interval Repetitions Overlapping Time-interval Repetitions Resusing Modeling ElementsSept 15 - IVV Annual Workshop10

11. More Reusable Modeling Elements Behavioral and structural products for conceptual system and subsystem views Written Use Cases, Use Case Diagrams, Activity Diagrams, Sequence Diagrams, Communication Diagrams, State Diagrams, Class Diagrams Goals, Constraints, External Actors/Stakeholders, Some Internal Actors, Actions/Functions Reuse by Context: Subsystem, Behavior, Design Choices, Mission Characterizations 2009 IVV Annual Workshop11Sept 15 - Reusing Modeling Elements Note: The actions/functions in Behavioral Diagrams may be reusable but not necessarily in the sequence defined in the diagrams

12. More Reusable Modeling Elements SysGoals Product PBRA Products Assertions Behavioral and structural products associated with design subsystem component views Other Reports, References, Templates 2009 IVV Annual Workshop12Sept 15 - Reusing Modeling Elements

13. Example: SysGoals Product Characterize/Classify Missions by: Mission Type: Orbiter/Lander Location/Destination: Earth Orbit, Non-Earth Planetary Orbit Orbit Type: LEO, Polar, Geocentric, etc. Number of Orbiters, Solo/Cluster Overall Objectives and Science Requirements Communication Signal Bands and Availability Autonomous vs. Commanded Operations Length of Mission Launch and Landing Plans Environment/Conditions Environmental Limitations and Safety Precautions Capabilities, Limitations, and Risks 2009 IVV Annual Workshop13Sept 15 - Reusing Modeling Elements

14. Modeling Reuse with Classifications Identify Commonalities and Differences Associate Goals to Characterizations Associate Sub Goals to Characterizations Develop Reusable SysGoal Products in respect to context by characterization 14Sept 15 - Reusing Modeling Elements2009 IVV Annual Workshop Common and Generic Goals, Behaviors, Actions, Actors, etc. Additional and Specific Goals, Behaviors, etc. for Classification

15. NEAP Project 2009 IVV Annual Workshop15Sept 15 - Reusing Modeling Elements

16. Reuse Process 16Sept 15 - Reusing Modeling Elements2009 IVV Annual Workshop Reuse Repository Reuse Repository Discovery Packaging Classification Search Validation Adaptation/ Integration

17. SRM Reuse Framework Three initial use cases to identify the actors and behaviors of the desired reuse library: Add SRM artifacts to the reuse library Browse the reuse library Retrieve and reuse SRM artifacts 2009 IVV Annual Workshop17Sept 15 - Reusing Modeling Elements

18. Use Case: Add SRM Artifacts 2009 IVV Annual Workshop18Sept 15 - Reusing Modeling Elements

19. Use Case: Browse Artifacts 2009 IVV Annual Workshop19Sept 15 - Reusing Modeling Elements

20. Use Case: Browse by Activity 2009 IVV Annual Workshop20Sept 15 - Reusing Modeling Elements

21. Use Case: Retrieve and Reuse 2009 IVV Annual Workshop21Sept 15 - Reusing Modeling Elements

22. Conceptual Model 2009 IVV Annual Workshop22Sept 15 - Reusing Modeling Elements

23. Elements in the Prototype 2009 IVV Annual Workshop23Sept 15 - Reusing Modeling Elements

24. Intermediate Reuse Repository Reuse Working Group is using svn to control new reuse artifacts within a Together Project: The Reuse Repository Working Group acts as current librarian to define or accept new reuse additions The Reuse Repository will provide different folder views to browse by: [contexts] Behavior Product Subsystem (associate reusable products) Design Component (associated reusable products) Project {All contexts may be further decomposed by classifications} 2009 IVV Annual Workshop24Sept 15 - Reusing Modeling Elements

25. A Prototype Beyond svn Eclipse plugin Must integrate with other tools used by the IV&V team First prototype will support Only basic searches by id and name Backend database is object-oriented Artifacts maintained in the XML format Sept 15 - IVV Annual Workshop25Resusing Modeling Elements

26. Conclusion Short-term Goal Implement the prototype Intermediate Reuse Repository using svn  Evaluate the prototype for its effectiveness  Promote the use of Intermediate Reuse Repository with a pilot project Start the construction of a basic proof-of-concept prototype that supports only a limited number of elements in the reuse conceptual model Long-term Goal Meet the Objectives and Goals of the Reuse Working Group  Reuse (of modeling elements) becomes a fully integrated aspect of the IV&V workflow 2009 IVV Annual Workshop26Sept 15 - Reusing Modeling Elements

27. Questions? 2009 IVV Annual Workshop27Sept 15 - Reusing Modeling Elements