1. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 1 GLAST Large Area Telescope: Instrument Flight Software Development Plan Gunther Haller Stanford Linear Accelerator Center Manager, Electronics, DAQ & FSW LAT Chief Electronics Engineer haller@slac.stanford.edu (650) 926-4257 Gamma-ray Large Area Space Telescope

2. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 2 LAT FSW Development Overview FSW is an integral part of the data acquisition (DAQ) subsystem and is managed, budgeted and scheduled as part of the DAQ subsystem FSW releases will therefore be coordinated with the major DAQ hardware releases in both timing and content FSW development plan follows the spiral design model used in almost all high energy physics data acquisition experiments with great success

3. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 3 LAT DAQ Architecture 16 Tower Electronics Modules –DAQ electronics module (DAQ-EM) –Power-supplies for tower electronics * Primary & Secondary Units shown in one chassis 3 Event-Processor Units (2+1 spare) –Event processing CPU –LAT Communication Board Spacecraft Interface Unit* –Spacecraft Interface Board (SIB): Spacecraft interface, control & data –LAT control CPU –LAT Communication Board (LCB): LAT command and data interface Power-Distribution Unit (PDU)* –Spacecraft interface, power –LAT power distribution –LAT health monitoring Global-Trigger/ACD-EM/Signal-Distribution Unit* TKR CAL

4. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 4 LAT FSW Releases This strategy calls for major FSW releases to coincide with the natural hardware builds as follows: –R1 – Engineering Model 1 (7/1/03) Single tower, single CPU –R2 – Engineering Model 2 (1/1/04) Multiple towers, GASU*, single CPU –R3 – Full LAT (9/1/04) Complete set of 16 towers, GASU*, full set of CPU’s Major milestones above will be referred to later in the presentation * GASU includes LAT Global Trigger, LAT Event-Builder

5. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 5 Team Small effective group Very experienced Excellent track record Employ highly interactive development process All members are expert in LAT architecture, able to contribute in many areas Leads are highly qualified scientists Leads are also developers Independent oversight provided by systems engineering Produce fully documented design Process allows/requires software to be in use from early subsystem development/testing to full LAT verification FSW Lead Scientist J.J. Russell Project Manager (IPM) W. Althouse Electronics & FSW Manager G. Haller FSW Test/QA Oversight S. Sawyer Configuration Manager A.P. Waite Performance & Safety Assurance D. Marsh I&T Support C.Brune Boot & S/C Interface D. Wood Algorithms J.J. Russell LAT Internal Cmd & Config M. Huffer T&C A.P. Waite Thermal Control J. Swain DAQ M. Huffer Test Executive S. Maldonado Front End Simulators O. Saxton

6. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 6 LAT FSW Development Process Initial design effort –Concentrate on hardware interfaces and architecture definition –Build stable development infrastructure –Generate high-level requirements (SRS) that capture scope of project –Generate high-level design that captures basic architecture and interfaces For each FSW release –Generate detailed design of new functionalities –Employ iterative design/code/test process to converge on the detailed design (“little spirals”) Allows experienced developer to proceed more rapidly to explore the design parameter space, discover issues, and resolve them Ultimately produces a more optimal design than one selected in advance based only on analysis and limited data Extensive documentation of resulting code is produced as it is built Iterative process is a continuous rapid prototyping cycle that supports higher productivity and a higher quality final product Activity Time Coding Architecture, design Qualitative example for 3 major spirals

7. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 7 Oversight and Reviews Detailed FSW development plan, schedule, and reviews were already part of LAT PCMS at PDR, down to the task level (WBS 4.1.7.9) Plan is being updated to reflect some modifications LAT CDR to serve as review of high-level design and progress to date on detailed EM1 design Incremental milestones for each package completion –Detailed in FSW Development Schedule –Will additionally be tracked and discussed in Weekly LAT-wide project meetings with discussion of each sub-system LAT Project Weekly Report Monthly LAT-wide PMCS reviews: system-specific past month’s accomplishments, plans for following month, risk evaluation, cost and schedule review of last month’s scheduled and budgeted versus actual accomplishments 1 st 20032 nd 20033 rd 20034 th 20031 st 20042 nd 20043 rd 20044 th 2004 Milestones Reviews CDR 4/29/03 EM2 Peer Review 10/1/03 EM1 Code Release 7/1/03 FU Peer Review 4/1/04 EM2 Code Release 1/1/04 FU Code Release 9/1/04 Beam Test 5/24/04-6/16/04 FU release to I&T 10/1/04

8. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 8 FSW Code Management FSW partitioned into functional blocks based on the SRS –Functional blocks are then mapped into packages, the fundamental unit of the code management system Package Development –Detailed design elements (algorithms, finite state diagrams, logic flows, etc.) and development notes are generated on a per package basis –Design information is stored in a Software Development Folder (SDF) which accompanies each package –Contents of SDF are version controlled alongside the package’s code using the code management system –As the software matures, design descriptions from the SDFs evolve along with the code to provide a complete set of detailed design documentation

9. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 9 Verification The LAT FSW team is implementing a test executive environment to capture explicit test descriptions consisting of: –Purpose of the test with a cross-reference to either a driving requirement or a design feature –Running instructions –Required hardware list –Required software list –Input vectors –Reference output vectors Test descriptions along with specialized test code/scripts form part of every code package Running a test generates a test instance in persistent storage (a random access database) System engineering supports process by providing test cases Formal qualification testing will occur on the final deliverable –Use detailed requirements captured in the test executive environment –Verify explicit traceability back to the SRS and higher level documents

10. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 10 A Single Development Cycle Design/DevelopDevelop/TestFormal Test Entrance:Sufficient knowledge/documentation to start design Activity:Start design, code small prototypes Entrance:Target hardware becomes available Activity:Code and test against real hardware (debug both) Entrance:Development complete, snapshot taken (release is defined) Activity:Test against the formal test plan Entrance:Formal test plan completed successfully Exit:Release to integration

11. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 11 Breakdown of Development Cycles 1 st 20032 nd 20033 rd 20034 th 20031 st 20042 nd 20043 rd 20044 th 2004 CDR 4/29/03 EM2 Peer Review 10/1/03 EM1 Code Release 7/1/03 FU Peer Review 4/1/04 FU release to I&T 10/1/04 EM2 Code Release 3/1/04 FU Code Release 9/1/04 EM1 cycle EM2 cycle FU cycle Beam Test 5/24/04-6/16/04

12. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 12 FSW Development on Per Package Basis Percentages in boldface represent what is required to satisfy the FSW test plan Percentages not in boldface are planned progress * Requirements not yet provided to FSW team Application code: 40 LOC/person/day Boot code: 10 LOC/person/day

13. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 13 FSW Development on Per Package Basis Percentages in boldface represent what is required to satisfy the FSW test plan Percentages not in boldface are planned progress * Requirements not yet provided to FSW team Application code: 40 LOC/person/day Boot code: 10 LOC/person/day

14. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 14 FSW Development on Per Package Basis Percentages in boldface represent what is required to satisfy the FSW test plan Percentages not in boldface are planned progress Application code: 40 LOC/person/day Boot code: 10 LOC/person/day Remaining Code: HEP 71050 SC 6150 Total 77200

15. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 15 Schedule (page 1 of 6)

16. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 16 Schedule (page 2 of 6)

17. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 17 Schedule (page 3 of 6)

18. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 18 Schedule (page 4 of 6)

19. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 19 Schedule (page 5 of 6)

20. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 20 Schedule (page 6 of 6)

21. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 21 Staffing Personnel resources –SLAC: 6 FTE –NRL: 1 FTE currently, searching for a second Period of performance –20 months currently shown until LAT Pre-Ship Review –Assume 18 months available for FSW development Overhead –Schedule assumes LAT FSW Team Leads – 20% maximum LAT FSW Team (SLAC) – 10% maximum LAT FSW Team (NRL) – 15% maximum Above figures reflect levels from previous experiments

22. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 22 Productivity Assumptions / Constraints –LOC estimates only for remaining work (~16% LOC already complete) –1.5 calendar years available for remaining work –Overhead as previously described accounted for in above estimates Analysis –LAT-HEP code requires average rate of 38 LOC/person/day, allowing substantial margin relative to previous experiments –LAT-Boot/SC code (to be done principally at NRL) was calculated for 2 people and comes out near NASA standards at 10 LOC/person/day *LOC production rates for BaBar/SLD are averaged over entire development cycle (see slide 6). LOC production was actually higher after the architecture phase (i.e. where LAT is now). In other words, these estimates provide lower limits for LOC production rates and LAT has more margin than shown. **Total Babar code is more than 500k lines, only dataflow part is listed since it could be analyzed for this presentation Experiment# CPUsMan- years LOCLOC/person/day SLD> 50012150K52* Babar> 20015170K**47* BFEM22.644K70 LAT – HEP3971.5K38 LAT – Boot & SC I/Fs136.1K10

23. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 23 Risks Design inputs not fully defined for certain FSW packages –Thermal Control System Work in progress by thermal group (ECD 5/1/03) –Calibration and Diagnostics Work in progress by science group (ECD 5/1/03) Must maintain team overhead as specified Design and/or hardware changes Lack of hardware availability

24. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 24 Software Testbed TEM DAQ Modules TEM Power Supplies TKR and CAL Electronics Simulators 12 ACD Electronics Cards Full DAQ set with EM2 hardware (each with identical interfaces and functionality as flight) before flight-hardware is available Incremental built according to plan All DAQ modules including 16 TEM’s TKR and CAL front-end electronics for 1 tower, front-end simulator boards for other 15 towers Full set of ACD EM2 electronics Spectrum Astro SC simulator Excellent software testbed Spectrum Astro Simulator

25. GLAST LAT ProjectGLAST Flight Software, 7 February 2003 FSW Development Plan 25 Summary Described FSW development plan –Detailed package breakdown –Schedule –Staffing –Milestones and reviews –Verification & test plan Personnel in place –Modulo one extra person at NRL On track, requirements and schedule more than sufficiently defined for the current phase of the project This is the plan we are executing.