220 likes | 528 Vues
Data Communications Program. Data Comm Trials and Production Requirements: High Level Impact. Presented To: DCIT #23 Plenary Prepared By: Data Comm Production Sub WG Date: 9 May 2013 . DCIT #22 Action Item.
E N D
Data Communications Program Data Comm Trials and Production Requirements: High Level Impact Presented To: DCIT #23 Plenary Prepared By: Data Comm Production Sub WG Date: 9 May 2013
DCIT #22 Action Item • Carry over from last DCIT meeting to show impact of Trials on the Production system as risk mitigation. • Provide insight into the numbers and types of requirement changes from DCIT and Trialsthat have impacted Production system. • Include pre-DTAP PTR changes, e.g., drop UM73 and add UM79 and UM83 • Categorize the changes, e.g., break the system vs. nice-to-have vs. new requirements • Provide high level assessment of impact to Production system • Risk reduction – show how these would have otherwise created problems with Production system. • Qualitative assessment -ROM would be desirable but at least provide High, Med, Low qualitative.
Requirement Changes: Life Cycle Impact • Pre-March 2012 • Major requirements changes prior to initial Production baseline in March 2012 (ERAM CDR Baseline, TDLS Initial Baseline WSSD 2.0) • Requirements • Drop UM73 • Cleared as Filed • UM79, UM83 for revisions rather than UM80 • Modifications for FMS auto loading, especially concerning transition fixes • Benefits • Most required for operational acceptability • Allow auto-loading across various types of equipage • Identified variations/anomalies with FANS standards • Impact • ~30 changes in March 2012 WSSD • Majority are high impact, e.g., operationally required and resulted in new messages, new CHI
Requirement Changes Life Cycle Impact – cont’d • Post-March 2012 Changes • Requirements • Delayed Session Termination • Dispatch Copy Format and Timing/Gate Request Message • Initial UM79 • Second Frequency/Contact • Various PTRs (see next slides) • Benefits • Additional modifications for operational acceptability • Additional sites/operational scenarios • Impact • ~10 changes in Sept 2012, some to revise previous requirements • ~41 total WSSD changes • ~4 IRD changes across 3 IRDs • = ~45 total • DCL changes are generally high impact, e.g., operationally required and resulted in new messages, new CHI • AOC changes are medium to low impact
DTAP PTRs impact on S1P1 Summary • PTRs from DTAP • Production SE tower sub-team scrubbed #1-110 with DTAP Test Team at Tech Ctr in Feb 2013; approx. 25 marked as potential impact to S1P1 • Current PTR file (April 23) has 155; MITRE has scrubbed 111-155 but these have not yet been reviewed by full Production sub-team team • Most PTRs assumed to affect TDLS, but some could also impact ERAM, e.g., logon, or interfaces • Rapid turnover during Trials testing (MEM and now EWR) is a challenge • Categories • Avionics, including CHI • Ground System, including CHI • AOC Interface • Test Cases
DTAP PTRs impact on S1P1 Summary- cont’d • Impact • Many PTRs not applicable due to differences in architecture and software systems • Most valuable in identifying avionics issues, which will be applicable to Production as well • Some scenarios represent good test cases even if no requirement or design change; mitigates risk of not finding lower level problems by providing complex scenarios • May have resulted in design changes even if no specific requirement changes, e.g., FEC and CAF changes impact on CSCI allocations and CHI • Quick Look – high level summary only • ~26 PTRs with requirement impact • ~25 PTRs with analysis, design or test impact
DTAP PTRs Impact on Production: Quick Look Total DTAP PTRs = 155
Observations/Lessons Learned: Maturity • Ideal = Serial • Trials “try out” and validate operational requirements • If valid, then transferred to Production for system implementation • Reality = Parallel • Trials still changing requirements • Production baselined in March 2012 for Logon and flight data (En Route) • Tower held open to 4/15/13 • Trials mitigate operational acceptability risk but may add schedule risk to Production
Observations/Lessons Learned – cont’d • Handoff/Tech Transfer from DCIT/DTAP to Production • New Requirements • Need tech transfer documentation vehicle to clearly capture the problem, disposition across multiple spec docs, and track • Formal DCIT Plenary agreement on Req->DTAP specs->Trials ->Refine Req ->Handoff to Production->Production specs->SW Development • PTRs are bugs against Reqs; should not be used for new requirements, although some are listed as out of scope on PTR list • Forum • DCIT WG reps, DTAP and S1P1 SE need to all be involved in “handoff” to ensure operational and system requirements are well understood
Observations/Lessons Learned – cont’d • Implementation in Production • Impacted by differences in system architectures • May require different requirements for Production system • May result in different potential impact than when proposed for Trials • Considerable SE LOE to understand, analyze and evaluate the DTAP PTRs for applicability to Production system • Understand requirement discrepancy, especially at lower levels • Evaluate maturity and consistency with other system requirements • Assess impact
Observations/Lessons Learned – cont’d • En Route Trials • Start DCIT En Route Trials as soon as possible to gain the most benefit • Need Serial, not Parallel • En Route use cases and specs will soon be leaving the station...
History - DCIT Requirement Changes • Primary Focus of DCIT is on the Trials • Jan – June 2011, DCIT #1-6 • Focus on team organization (WGs, charter, agreements, Trials site selection, processes) • June 2011, DCIT 6 • Flight Deck WG. Initial “requirements” discussions, e.g., complex clearances and autoloading into FMS, Tailored Arrivals • Initial operational E2E description, e.g., ops requirements • Outbrief on AOC-Tower data exchange, e.g., flight plan, courtesy copies (aka dispatch message), Subscriber DB • July-Sep 2011, DCIT 7-9 • Initial ops requirements for Revised DCLs using UM79, UM83 rather than UM80 • Initial discussions about airways, intersections, other auto-loading problems. • Initial discussions about session termination changes • Oct – Nov 2011, DCIT 10-11 • Initial discussions about providing DCL 45 min prior to P-Time • Reject of DM25 with concatenated free text • Initial discussions about CAF
History-cont’d • Jan – Mar 2012, DCIT 12-13 • AOC Courtesy Copy initial format discussions • Initial delayed session termination requirements • CAF requirements • Apr-June 2012, DCIT 14-16 • Added route string to AOC Dispatch message for CAF • July – Dec 2012, DCIT 17-20 • Refinements based on additional avionics and DTAP testing • Multiple AFN Log On’s • DM25, including multiple downlink requests • CAF • Lat/longs, NAT Tracks • Jan – Mar 2013, DCIT 21-22 • AOC Dispatch Message format changes, e.g., headers • UM83 switch (revert to UM80 when disabled) • Route string to AOC message on revisions