Software and Digital Systems Safety (SDSS) Research Program

1. Software and Digital Systems Safety (SDSS) Research Program Barbara Lingberg FAA/AIR-120 SDSS Program Sponsor May 6, 2003

2. Acronym List • AVSI Aerospace Vehicle Systems Institute • COTS Commercial-off-the-shelf • CSTA Chief Scientific and Technical Advisor • FAA Federal Aviation Administration • FPGA Field-Programmable Gate Array • FY Fiscal Year • HUMS Health Usage Monitoring System • IMA Integrated Modular Avionics • ISS Information Systems Security

3. Acronym List (cont) • IT Information Technology • LAN Local Area Network • MC/DC Modified Condition/Decision Coverage • NASA National Aeronautics & Space Administration • OO Object-oriented • OS Operating System • RTOS Real-Time Operating System • SDSS Software and Digital Systems Safety • TCRG Technical Community Research Group

4. Briefing Outline • SDSS Research Program Purpose • SDSS Technical Community • SDSS Research History • SDSS Research Priorities • Overview of SDSS Tasks

5. SDSS Research Program Purpose • To address safety, performance, and technology issues in the areas of: • Software • Complex electronic hardware • Digital systems • SDSS research supports the policy and guidance initiatives of the FAA

6. SDSS Technical Community Research Group (TCRG) • Leader: Leanna Rierson, CSTA for Aircraft Computer Software • Sponsor: Barbara Lingberg • Program Manager: Chuck Kilgore • Members: • Will Struck • Jorge Castillo • Robin Sova • Gary Horan • Brenda Ocker • Dennis Wallace • John Lewis • Jim Treacy • Tony Lambregts • Tom Kraft • Larry Bessette • Steve VanTrees

7. SDSS Research History • Past Research in the Areas of: • Modified Condition/Decision Coverage (MC/DC) • Service History • COTS Software • COTS Hardware • COTS RTOS • Structural Coverage of Object-oriented Software • See FAA Software Website for Reports: • http://av-info.faa.gov/software

8. SDSS TaskPriorities (as of Sept 2002)and Activation Status Status PriorityTask Done 1 COTS software and component protection FY03 2 Microprocessor evaluations FY03 3 Object oriented technology • 4 Complex electronic hardware case study FY035 Semiconductor wearout effects $$ 6 Databus evaluation criteria $$ 7 Structural coverage at the object code level FY03 8 COTS component integration (follow-on to 1 above) • 9 Software verification tools assessment $$ 10 Safety engineering in software Legend • -In Work FY03 -Start in FY03 $$ -Start in FY04+ Done -Complete

9. SDSS Task Priorities and Activation Status (cont) Status PriorityTask Done 11 Augmented manual control (fly-by-wire/light) • 12 Ethernet as an aviation databus (related to 1, 6, 8, 22) $$ 13 Adaptive flight controls for general aviation $$ 14 Requirements engineering management $$ 15 Advanced guidance & control system functional design $$ 16 Tool qualification of complex electronic hardware • 17 Software development tools assessment $$ 18 Flight critical systems design assurance • 19 Real-time scheduling analysis $$ 20 Accelerated life qualification methods Legend • -In Work FY03 -Start in FY03 $$ -Start in FY04+ Done -Complete

10. SDSS Task Priorities and Activation Status (cont) Status PriorityTask $$ 21 Avionics computer resource issues $$ 22 Wrappers with COTS software (follow-on to 1, 8 above) $$ 23 Local area networks onboard aircraft • 24 Software service history case study • 25 COTS ground systems verification $$ 26 Criteria for burn-in testing $$ 27 Environmental qualification of electronic components $$ 28 Transfer of aviation data on the internet $$ 29 Software service history and reliability models Legend • -In Work FY03 -Start in FY03 $$ -Start in FY04+ Done -Complete

11. Task Categories • COTS-Related • Verification • Complex Hardware • Complex Hardware Environment • Databus • Flight Controls • IMA-Related • Software Tools • Service History

12. COTS-Related Tasks PriorityTask 1 COTS Software and Component Protection 2 Microprocessor Evaluations 8 COTS Component Integration 22 Wrappers with COTS Software 25 COTS Ground Systems Verification

13. Verification Tasks PriorityTask 3 Object Oriented Technology 7 Structural Coverage at the Object Code Level

14. Complex Hardware Tasks PriorityTask 4 Complex Electronic Hardware Case Study 5 Semiconductor Wearout Effects 16 Tool Qualification of Complex Electronic Hardware

15. Complex Hardware Environment Tasks PriorityTask 20 Accelerated Life Qualification Methods 26 Criteria for Burn-in Testing 27 Environmental Qualification of Electronic Components

16. Data / Databus Tasks PriorityTask 6 Databus Evaluation Criteria 12 Ethernet as an Aviation Databus 23 Local Area Networks (LANs) onboard Aircraft 28 Transfer of Aviation Data on the Internet

17. Flight Control Tasks PriorityTask 11 Augmented Manual Control 13 Adaptive Flight Controls for General Aviation 15 Advanced Guidance & Control System Functional Design 18 Flight Critical Systems Design Assurance

18. IMA-Related Tasks PriorityTask 10 Safety Engineering in Software 14 Requirements Engineering Management 19 Real Time Scheduling Analysis 21 Avionics Computer Resource Issues

19. Software Tools Tasks PriorityTask 9* Software Verification Tools Assessment 17 Software Development Tools Assessment *AIO Funded 1st Year

20. Software Service History Tasks PriorityTask 24 Software Service History Case Study 29 Software Service History and Reliability Models

21. Research Affiliations • NASA’s Aviation Safety Program • Aerospace Vehicle Systems Institute (AVSI) • Individual Companies • Universities

22. Potential IT and ISS Task Collaboration 1 COTS software and component protection 6 Databus evaluation criteria 8 COTS component integration 12 Ethernet as an aviation databus 22 Wrappers with COTS software 23 Local area networks onboard aircraft 25 COTS ground systems verification 28 Transfer of aviation data on the internet

23. More Information • See FAA software website for research reports • http://av-info.faa.gov/software • Contacts for detailed task information • Barbara.Lingberg@faa.gov or Leanna.Rierson@faa.gov

24. Background Slides

25. COTS-Related Tasks (1, 2, 8, 22, & 25) • Tasks 1 & 8: Evaluate COTS operating systems (OS), integration techniques, and protections schemes. Focus on RTOS integration. • Task 2: Develop criteria for new microprocessor technology. • Task 22: Investigate use of wrappers for protecting against problems in COTS components. • Task 25: Evaluate COTS issues in support of health-usage monitoring system (HUMS) (e.g., safety, security, & integrity).

26. Verification Tasks (3, 7 & 9) • Task 3 - Identify and address object-oriented issues in airborne software. To date research has focused on structural coverage. New task will focus on data and control coupling. • Task 7 - Determine if structural coverage (MC/DC in particular) at the object code level is a feasible alternate to the source code level.

27. Complex Hardware Tasks(4, 5, & 16) • Task 4 – Perform a case study using RTCA/DO-254. On-going with NASA Langley: • Designed a field-programmable gate array (FPGA) using RTCA/DO-254 (SPIDER). • Data will be used to support FAA training and to identify areas where clarification is needed. • Task 5 – Identify and address effects of semiconductor wearout. • Task 16 – Develop criteria for accepting tool experience and evaluating accuracy (for tools used in complex hardware design or verification).

28. Complex Hardware Environment Tasks (20, 26, & 27) • Task 20 (Accelerated life qualification) – Develop methods to analyze and test devices in order to establish life limits for the equipment, if necessary. • Task 26 (Burn-in testing) – Develop burn-in testing criteria for critical electronic equipment. • Task 27 (Environmental qualification) – Develop methods to determine reliability of components, when installed in more severe environment than originally designed for.

29. Data / Databus Tasks (6, 12, 23, & 28) • Task 6 – Evaluate a number of databuses and develop criteria for evaluation. Driven by the biz-jet architectures. • Task 12 – Identify safety issues with Ethernet and address them. Driven by the large transport architectures. • Task 23 - Identify and address safety concerns regarding networks used for loading flight critical data and serving passengers. • Task 28 (transfer of data on internet) - Evaluate safety and security issues of transferring flight critical data via internet.

30. Flight Control Tasks(11, 13, 15, & 18) • Task 11 – Identify guidance materials for fly-by-wire systems • Task 13 – Develop and implement nonlinear adaptive control concepts for general aviation aircraft • Task 15 - Identify guidance materials for advanced guidance and flight control systems • Task 18 - Identify guidance materials for flight critical systems architecture design assurance

31. IMA-Related Tasks(10, 14, 19, & 21) • Task 10 (safety engineering) - Evaluate the safety assessment processes and their applicability in software assurance. • Task 14 - Identify techniques and practices for management of overall system requirements. Particularly, focused on complex, integrated avionics, with multiple developers. • Task 19 - Identify and address safety issues of real-time schedulers. • Task 21 - Identify IMA issues and propose solutions for safe implementation. Focuses on the integration aspects of IMA.

32. Software Tools Tasks (9 & 17) • Task 9 - Identify software verification tool qualification issues and propose solutions to help cert authorities & applicants. Focus is on structural coverage tools. • Task 17 - Identify software development tool qualification issues and propose solutions to help cert authorities & applicants.

33. Software Service History Tasks (24 & 29) • Task 24 - Document criteria for applying software service history based on an actual project and using previously-developed handbook • Task 29 - Consider use of software service history & reliability models.