I/ITSEC Tutorial #1019 The Basics of the M&S VV&A Process

1. I/ITSEC Tutorial #1019 The Basics of the M&S VV&A Process Simone Youngblood The Johns Hopkins University Applied Physics Laboratory Simone.Youngblood@jhuapl.edu

2. Agenda • Definitions • The VV&A Processes • VV&A as Applied to the Simulation Categories • The Key Players • Conceptual Model • Documentation • Conclusion

3. Definitions

4. What is Verification? • The process of determining that a model or simulation implementation and its associated data accurately represents the developer's conceptual description and specifications. • Addresses the structural integrity and the stability of the model • Goal: Did I build the model or simulation RIGHT?

5. What is Validation? • The process of determining the degree to which a model or simulation and its associated data are an accurate representation of the real world from the perspective of the intended uses of the model. • Addresses the representational aspects of the model or simulation • Goal: Did I build the RIGHT model or simulation?

6. What is Accreditation? • The official certification that a model or simulation and its associated data are acceptable for use for a specific purpose. • The accreditation decision is based on an accreditation assessment of the V&V evidence. • Goal: Are the results of the M&S FITFOR PURPOSEand USEFUL for making decisions?

7. VV&A Risk Resources Balancing the cost of knowing against the risk of assuming. The Balancing Act

8. The VV&A Processes

9. VV&A and the Problem Solving Process From the DOD RPG

10. Tailoring Guidance for VV&A : Stay Focused on the Problem • Maintain a problem orientation • Understand the relationships between • The problem being solved • The role of M&S in the problem • The role of VV&A in establishing M&S credibility • If the problem is too complex, decompose it into workable units • Ensure that you are still trying to solve the same problem • Focus on accreditation • Ensure that the V&V evidence is clearly applicable to the intended purpose - solving ‘this’ problem

11. Tailoring Guidance for VV&A : Understand the Requirements • Define the explicit problem requirements • What specific questions are to be answered? • How will M&S be used? • What does the M&S need to do? • How good does the M&S need to be? • Define what question(s) need to be answered... • Assess the completeness, correctness, and consistency of the M&S requirements • Define the acceptability criteria needed to assess M&S attributes • Identify the M&S options, the VV&A credibility needs, and the level of resources necessary to meet defined requirements An explicit statement of the requirements is the most important aspect of cost-effective VV&A and the hardest to come by

12. Tailoring Guidance for VV&A : Know the Level of Credibility Required • Credibility is Defined by the Customer - but it has a cost • Ensure that the User determines the level of credibility needed • Ensure the level of credibility is explicitly defined by the Acceptability Criteria • Credibility and Risk Assessment - know the limits & tolerances • How will incorrect simulation results affect the ‘end user’ decision • What are the costs in time and resources • Tailor Risk Analysis to Level of Credibility Requirements • Determine how much evidence will be needed to accredit M&S • Determine the impact of NOT doing (or failing) V&V • Provide mechanisms to facilitate development of workaround strategies and assessment of these solutions

13. Tailoring Guidance for VV&A: Determine How to Optimize Resources • Not all V&V supports Accreditation to the same extent • Understand what each type of V&V evidence ‘buys’ you relative to the cost of producing it • Determine which techniques to apply to derive required level of credibility • Try to avoid (re)doing it all yourself • Capitalize on existing VV&A information whenever possible • Know how to extract useful data from software V&V results • Cooperative application of resources : use common VV&A data elements and report structure • The VV&A Templates provides a common structure for documenting VV&A information • Each of the Services has adopted a common database structure for their M&S Resource Repositories

14. VV&A as Applied to the Simulation Categories

15. Simulation Categories New M&S Development Any stand-alone model or simulation under development being built to address the intended purpose or purposes of the User. Legacy Any model or simulation that was developed either in the past or for a different purpose. Federation A system of interacting models and/or simulations, with supporting infrastructure, based on a common understanding of the objects portrayed in the system.

16. Accept & Record Solution Analyze Results Define Problem Establish Objectives M&S Method Define M&S Rqmts Plan Approach VV&A and New M&S Development PROBLEM SOLVING PROCESS Repository Apply Results Select Approaches Non-M&S Methods ` M&S USE PROCESS Execute and Prepare Results M&S DEVELOPMENT/PREPARATION PROCESS Develop New M&S Prepare M&S for Use Plan M&S Develop-ment Develop Design Imple-ment & Test Refine M&S Rqmts Develop Con-ceptual Model yes no Make Accreditation Decision Verify Rqmts Validate Results Verify Design Verify Imple-ment-ation Validate Concep-tual Model Develop Accreditation Plan Develop V&V Plan Perform Accreditation Assessment V&V PROCESS Collect and Evaluate Accreditation Information ACCREDITATION PROCESS

17. Challenge Issues that Impact VV&A Implementation • The lack of a well defined referent • Determining how to use and when to use Subject Matter Experts • The lack of insight into the M&S • The lack of M&S stability • Starting the V&V/A process “late” • Keeping the second “V” in V&V

18. Is There Sufficient Can the M&S be Info to Assess the Used? M&S? Is the Info Are the on M&S Capability Requirements Adequate? Adequate? VV&A and Legacy M&S [ AA ] Accreditation Agent [ User ] User Define User [ AA ] Accreditation Agent [ User ] User [ Dev ] Developer [ VV ] V&V Agent Requirements AA [ Dev ] Developer [ VV ] V&V Agent [ Prop ] M&S Proponent [ Prop ] M&S Proponent User Select Legacy M&S AA NO Plan/Conduct Accreditation Reject Assessment YES M&S AA User AA YES NO Use Modify Use As - Is As - Is or Modify? User V&V as YES YES Prop AA AA Needed VV VV Plan M&S NO NO VV Modification Prepare M&S Obtain Needed Refine Requirements Prop. User for Use Information and Verify And Verify Dev, VV Prop User Prop, Dev Modify and Dev AA, VV AA, VV Verify Issue Dev, VV Validate Accreditation Prop Decision VV User User

19. Advantages of Using Legacy M&S • Starting with a legacy simulation may be more expedient, requiring less time and fewer resources than a new development • The experience of previous developers and users may be leveraged to establish a knowledge base that can provide guidance and support training • Testing and VV&A histories can provide evidence of simulation capabilities and limitations allowing the current effort to focus on high risk areas • A legacy simulation with a good reputation for providing credible results in similar applications can increase the simulation’s credibility (i.e., the User’s confidence in the simulation’s ability to address the current situation) due to • the demonstrated ability to address similar requirements • the demonstrated capabilities of the existing simulation • the direct experiences of previous users who successfully applied the simulation to related problems

20. Disadvantages of Using Legacy M&S • The simulation was developed to address different requirements • Unexpected and undesirable side effects may occur during execution of the code • The simulation comes with specific hardware and software, which may be obsolete • The simulation comes with specific data needs, however the data to fulfill those needs may no longer be authoritative or available • Information about the simulation and its previous usage may be incomplete or inconsistent • Participants (e.g., Accreditation Agent, V&V Agent) may need time up front to acquire knowledge about the simulation

21. What Can Help Reduce Legacy V&V Cost • Documentation that can directly support the accreditation assessment can reduce the burden of an extensive discovery effort • Documentation that completely and accurately describes simulation capabilities and use history can reduce the discovery and training costs • A simulation under configuration control with an established user community that can provide necessary information can reduce the support and discovery costs • Participants familiar with the simulation can reduce the need for extensive training

22. Scope of the Distributed M&S Problem

23. Distributed M&S:Technical Interoperability • Characterized by the ability of federates to physically connect and exchange data • Involves the use of common standards, compatible interfaces and coordinated data structures • Elements of technical interoperability • Hardware compatibility • Standards compatibility • Time management coordination • Coordinated use of Runtime Infrastructure (RTI) services • Security issues From “HLA and Beyond: Interoperability Challenges” by Dahmann, Salisbury, Barry, Turrell, and Blemberg (99F-SIW-073)

24. Distributed M&S: Substantive Interoperability Issues • Simulation Interoperability focuses on the capability of federates, when connected, to provide adequate, accurate & consistent simulated representations that adhere to the principles of “fair fight” & address the mission objectives. • Elements of Substantive Interoperability • Logical interaction between entities modeled in different federates • Temporal resolution • Spatial resolution • Coherent relationships between the components of the physical environment

25. Define Federation Objectives Perform Conceptual Analysis Design Federation Develop Federation Analyze Data & Evaluate Results Plan, Integrate & Test Federation Execute Federation & Prepare Outputs FEDEP Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 FEDEP INFORMATION & PRODUCTS V&V Federation Conceptual Model Verify Federation Design Verify Federation Development Products Validate & Accept Federation V&V Federation Output Consolidate Federation VV&A Products • Verify Federation Objectives VV&A Overlay to the FEDEP Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 • Verify the Federation Objectives with the User /Sponsor. • Define the Federation Acceptability Criteria. • Assemble the Federation Referent. • Plan the VV&A activities. • Verify the Federation Conceptual Model internally. • Validate the Federation Conceptual Model against the Federation Referent and against the Federation Acceptability Criteria. • Verify the Federation Design internally. • Verify the Federation Design against the Federation Conceptual Model. • Verify the federation development products internally. • Verify the federation development products against the Federation Conceptual Model. • Validate the integrated federation results against the Federation Acceptability Criteria and against the Federation Referent. • Formulate federation acceptance/ accreditation recommen-dations. • Verify the federation outputs internally. • Validate federation output against the Federation Acceptability Criteria and against the Federation Referent. • Collect all VV&A products and lessons learned. • Assemble them into a VV&A package to support federation reuse. Top Level View of the VV&A Overlay to the FEDEP (IEEE 1516.4)

26. Verify Federation Development Products Verify Federation Objectives Validate & Accept Federation V&V Federation Output Consolidate Federation VV&A Products V&V Federation Conceptual Model Verify Federation Design 1.0 3.0 4.0 5.0 6.0 7.0 2.0 Support Identifying User/Sponsor Needs Support Developing Federation Scenarios Support Selecting Federates Support Developing FOM Support Planning Federation Execution Support Executing Federation Support Analyzing Data Contribute to Verifying FOM Contribute to Verifying Raw Execution and Derived Output Prepare Federation VV&A Products for Reuse Support Preparing Federation Design Contribute to Verifying Federation Scenarios Support Integrating Federation Plan Accreditation Activities Support Establishing Federation Agreements Support Developing Federation Conceptual Model Contribute to Verifying Integrated Federation Contribute to Verifying Federation Design Support Developing Federation Objectives Validate Federation Outputs Contribute to Verifying Federation Agreements Support Testing Federation Contribute to Verifying Federation Conceptual Model Support Preparing Federation Development & Execution Plan Contribute to Verifying Federation Objectives Support Implementing Federate Designs Validate Integrated Federation Results Validate Federation Conceptual Model Support Implementing Federation Infrastructure Assemble Federation Referent Perform Acceptance Assessment Support Developing Federation Requirements Define Federation Acceptability Criteria Contribute to Verifying Federation Infrastructure Contribute to Verifying Federation Requirements V&V Federation Data Sets Plan V&V Activities Tasks Associated with each VV&A Overlay Phase

27. The Key Players

28. User • The User wants to use the simulation to provide an answer or solve a problem; he is concerned that the simulation can provide credible answers. • The User defines the objectives and the requirements, scenarios and use cases, and generally serves as the subject matter expert (SME) for issues in the problem and user domains. • Ultimately the User is the one who decides whether the simulation is credible enough to use.

29. Accreditation Agent • The Accreditation Agent prepares for and conducts a cost-effective accreditation assessment that results in a logical, sufficient, and fully justified accreditation recommendation to the User. • The Accreditation Agent assists the User with activities that help establish the scope of the problem to be addressed. • The Accreditation Agent serves as the User’s advocate throughout the M&S development process.

30. Accreditation Agent Challenges • Ensuring the definition of the intended use • Using existing V&V documentation • Coping with configuration management difficulties • Locating appropriate Subject Matter Experts • Overcoming delay in appointment of the accreditation agent • Obtaining needed resources • Communicating the results of the accreditation assessment

31. V&V Agent • The V&V Agent plans and performs the verification and validation (V&V) activities • The V&V Agent ensures that sufficient evidence is gathered to demonstrate that the simulation meets the stated requirements in terms of their associated measures and acceptability criteria.

32. V&V Agent Challenges • Obtaining well-defined accreditation information needs • Dealing with missing documentation • Establishing V&V support system and infrastructure • Finding adequate resources • Selecting the right people • Managing the V&V effort • Leveraging configuration management resources • Tracking and reporting V&V effort progress

33. Conceptual Model

34. Definition “The conceptual model is a simulation developer’s way of translating modeling requirements into a detailed design framework, from which the software, hardware, networks, and systems/equipment that will make up the simulation can be built, modified, or assembled.” from SIW Paper 00F-SIW-019, “Simulation Conceptual Model Development Issues and Implications for Reuse of Simulation Components” by Dr. Dale Pace

35. Why Conceptual Models? • “The biggest indication that Trespasser had game design problems was the fact that it never had a proper design spec…. Trespasser started and finished weak in the game design, and this affected every other part of the project.” • Richard Wyckoff, “Postmortem: DreamWorks Interactive’s Trespasser” Gamasutra, May 14, 1999. From presentation 03F-SIW-080.ppt by Gustavson, Turrell, Zimmerman at Fall 2003 SIW

36. Why Conceptual Models? • “We never had a proper design document, which meant that we generated a lot of code and art that we later had to scrap. What’s worse, because we didn’t have a detailed outline of what we were trying to build, we had no way to measure our progress (or lack thereof) accurately. We only realized that we were in trouble when it became glaringly obvious. If we’d been about the design rigorous up front, we would have known that we were slipping much sooner.” • Brian Upton, “Postmortem: Red Storm's Rainbow Six” Gamasutra, January 21, 2000. From presentation 03F-SIW-080.ppt by Gustavson, Turrell, Zimmerman at Fall 2003 SIW

37. Conceptual Model Components Requirements Specifications (1) Simulation Context Authoritative Information re: relevant entities/processes, data, algorithms, assumptions, behaviors, etc. Sets constraints/bounds on the Simulation Concept Simulation Concept (2) Mission Space -- Representation Aspect Simulation Elements Entities/processes represented (tasks, actions, behaviors, etc.) by assumptions, algorithms, data, and relationships (architecture) (3) Simulation Space Operational/functional capabilities Constraints Conceptual Model

38. Benefits of a Conceptual Model • A good conceptual model can improve requirements • Good requirements are important because • Faulty requirements cause half of software errors • Late error detection/correction is much more expensive than early error detection/correction • A good conceptual model allows early • Estimation of simulation fidelity • Development of validation sampling methodology • Assessment of simulation validity for the intended use • Determination of compatibility with other M&S/tools

39. Conceptual Model Documentation • Conceptual Model Portion Identification • Principal Simulation Developer POCs • Requirements and Purpose • Overview • General Assumptions • Identification of Possible States, Tasks, Actions, and Behaviors, Relationships and Interactions, Events, and Parameters and Factors for Entities and Processes being described • Identification of Algorithms • Simulation Development Plans • Summary and Synopsis

40. Documentation

41. Documentation Philosophy • Organize information according to a standard outline • Rationale • Eases the comparison of data with accreditation requirements • Facilitates V&V data accumulation for future use • Reduces costs of multiple accreditations over time • Specific outlines vary with type of data element • Structure V&V results to facilitate comparison with M&S requirements • Include description of how the results impact m&s use • State newly discovered discrepancies as assumptions, limitations on model use, or as errors • Identify the range of applicability for all results (particularly regarding any limitations or errors) • Ensure results are linked to the applicable M&S version • Configuration Management

42. MIL-STD 3022: VV&A Documentation Templates

43. VV&A Data Archiving • VV&A Documents • Should be archived in central location: • Defense Department level or • Program level • Indexed in a electronic database • Possibly available on-line • Electronic Database • Should contain summarized, unclassified data from VV&A reports • Should be sufficient for model comparisons and selection VV&A data are only useful if they are documented, and the documentation is readily available to model users.

44. Conclusion

45. Summary of VV&A • Cost-effective accreditation requires • Complete problem definition • Clear application description • Explicit statements of M&S requirements and acceptability criteria • A well-planned, tailored and focused accreditation assessment effort • Efficient V&V to support accreditation requires • A clearly defined application context to permit focused V&V efforts • The use of risk to focus and tailor the V&V effort • A clear understanding of how each V&V activity contributes to M&S credibility • A means of extracting key accreditation support information from previous V&V (and other M&S) efforts • An efficient means to produce, document, and archive all V&V information (from software and M&S V&V)

46. Simone Youngblood Simone.Youngblood@jhuapl.edu (240) 228-7958