1、Lessons Learned Entry: 1104Lesson Info:a71 Lesson Number: 1104a71 Lesson Date: 1999-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: International Space Station Program/Hardware-Software/Qualification Testing-Verification and Validation Description of Driving Event: Use
2、 of Hardware Before Qualification Testing and the Use of Software Before Verification and ValidationLesson(s) Learned: Some hardware is being used in MEIT before it has completed qualification testing. Software is also often used before its verification and validation is complete. In both cases, mod
3、ification to the hardware or software may be required before certification is completed, thereby potentially invalidating the results of the initial MEIT testing.Recommendation(s): When it makes sense to deliver hardware or software to system-level testing such as MEIT before qualification/certifica
4、tion is complete, the effect of any qualification-induced changes must be carefully evaluated for implications for regression testing. Final testing should always be run with validated software and qualified hardware.Evidence of Recurrence Control Effectiveness: NASA concurs with the recommendation
5、and notes that the ISS Program requires regression evaluation for all modifications performed on flight hardware to assess whether certification, acceptance, or integration testing results are invalidated and must be performed again. The final flight configuration will be verified by regression test
6、ing as well as acceptance, mission sequence, end-to-end, and integration tests.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-The Space Station and Shuttle Payloads Office at KSC (Code NN) utilizes Flight, Flight Equivalent and GSE hardware and soft
7、ware for MEIT that has been certified through ISS Program Office control boards and panels for these tests. The boards and panels also specify regression tests with flight units when required through the directives they provide. The NN MEIT test schedules currently have regression tests planned for
8、modified or repaired hardware units and revised software per ISS Program Office control board and panel directives and requirements.Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panela71 Comp
9、utersa71 Risk Management/Assessmenta71 Softwarea71 Test & Verificationa71 Test Articlea71 Test FacilityAdditional Info: Approval Info: a71 Approval Date: 2002-02-12a71 Approval Name: Bill Loewya71 Approval Organization: HQa71 Approval Phone Number: 202-358-0528Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
