1、Best Practices Entry: Best Practice Info:a71 Committee Approval Date: 2000-04-03a71 Center Point of Contact: GSFCa71 Submitted by: Wilson HarkinsSubject: Pre-Flight Problem/Failure Reporting Procedures Practice: A formal procedure is followed in the reporting and documentation of problems/failures o
2、ccurring during test, pre-launch operations, and launch operations for both hardware and software. A separate system, the “Spacecraft Orbital Anomaly Report (SOAR)“, is used for the reporting, evaluation and correction of problems occurring on-orbit (see Reliability Preferred Practice No. PD-ED-1232
3、).Programs that Certify Usage: This practice has been used on all GSFC in-house flight programs in accordance with the GSFC Quality Assurance Requirements defined in Reference 2. Out-of-house contractors may use their system so long as it meets the provisions of the GSFC Quality Assurance Requiremen
4、ts and is approved by GSFC.Center to Contact for Information: GSFCImplementation Method: This Lesson Learned is based on Reliability Practice No. PD-ED-1250; from NASA Technical Memorandum 4322A, NASA Reliability Preferred Practices for Design and Test.This practice significantly enhances the probab
5、ility of mission success by ensuring that problems/failures occurring during ground test are properly identified, documented, assessed, tracked and corrected in a controlled and approved manner. Another benefit of the PFR procedure is to provide data on problem/failure trends. Trend data may then be
6、 analyzed so that errors are not repeated on future hardware and software.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Implementation Method:A formal procedure (Reference 1) establishes the GSFC system for the identification and documentation of P
7、roblem/Failure Reports (PFRs), the data collection and monitoring of PFRs, the risk assessment and rating of problems/failures, and the Project and Center management approvals of corrective actions. For hardware, the procedure begins with the first application of power (or first test usage for mecha
8、nical items) at the lowest level of assembly of qualification or flight configuration hardware. For software, the procedure begins with the first test use of the software item with a hardware item of the mission system at the component level or higher.Identification and Documentation of PFRs:Anyone
9、with knowledge of a problem or failure may initiate a PFR. PFRs are generated for any departure from a design, performance, testing, or handling requirement that affects the function of flight equipment, ground support equipment that interfaces with flight equipment or that could compromise mission
10、objectives. All GSFC generated PFRs begin as problem records identified on applicable Certification Logs (Ref. 3), Problem Records (Ref. 4) and work orders. After a PFR occurrence, the Certification Log and Work Order, as applicable, are used to document, define and control any repairs, fixes, or mo
11、difications that may be performed on the hardware or software.PFRs are generated and entered electronically into a PFR database, normally accessible on designated personal computers in hardware assembly and test areas. The PFR database programs on-screen instructions indicate certain required data t
12、hat is to be provided, and automatically assigns a PFR number for traceability. PFRs can be prepared manually on GSFC PFR Form 4-2 (Figures 1 b. The degree of confidence in ability to quickly diagnose the source or cause of the problem or failure;c. The potential risk to hardware or software posed b
13、y continuing the operations after the problem or failure;d. The consequences of terminating an operation in which a failure has occurred (e.g., thermal vacuum testing).Risk Assessment and Rating of Problems/Failures:The residual risk of each PFR must be considered by the FRB before it can be conside
14、red for closure. A two-factored risk rating system is used. The first rating factor identifies the impact that the problem/failure would have on the flight hardware and/or software performance capabilities if it occurred during the mission. Redundancy is ignored in establishing this rating. The fail
15、ure effect ratings are illustrated in Table 1.Table 1. PFR Failure Effect RatingsRATING FAILURE EFFECT3 Catastrophic or major degradation to mission, system or instrument performance, reliability or safety2 Moderate or significant degradation to mission, system or instrument performance, reliability
16、 or safety, defined as: a) Appreciable change in functional capability b) Appreciable degradation of engineering or science telemetry c) Causing significant operational difficulties or constraints d) Causing reduction in mission lifetime1 Negligible or no impact on mission, system, or instrument per
17、formance, reliability or safety.The second rating factor identifies the confidence in understanding both the cause(s) of the problem/failure and the effectiveness of the resulting corrective action. The failure corrective action ratings Provided by IHSNot for ResaleNo reproduction or networking perm
18、itted without license from IHS-,-,-are shown in Table 2.Table 2. PFR Failure Corrective Action RatingsRATING FAILURE CORRECTIVE ACTION1 The root cause of the problem/failure has been determined with confidence by analysis and/or test. Corrective action has been determined, implemented and verified w
19、ith certainty. There exists no credible possibility of problem/failure recurrence.2 The root cause of the problem/failure has not been determined with confidence. However, some corrective action has been determined, implemented and verified with certainty. There exists some possibility that the prob
20、lem/failure may recur.3 The root cause is considered to be known and understood with confidence. Corrective action has not been determined, implemented or verified with certainty. There exists some possibility that the problem/failure may recur.4 The root cause has not been defined with certainty. C
21、orrective action has not been determined, implemented nor verified with certainty. There exists some possibility that the problem/failure may recur.Any PFR with a failure effect rating of “2“ or “3“, coupled with a failure corrective action rating of “3“ or “4“ is identified as a Red Flag PFR indica
22、ting significant residual risk associated with the problem/failure in question. GSFC Project Manager signatures are required on all red flag PFRs. No delegation of signature authority is permitted. All red flag PFRs are highlighted at GSFC Project Flight Assurance Reviews.Project and Center Manageme
23、nt Approval of Corrective Actions:A PFR is considered for closure when the FRB determines that appropriate and sufficient investigation of the cause of the problem/failure has been completed and that commensurate corrective action has been completed and properly documented. The following signatures
24、are required to formally close a PFR:a. The Contractor Program/Project Manager and Contractor QC for PFRs initiated by off-site GSFC contractorsb. The GSFC FRB chairmanc. The GSFC Project Manager or his delegated FRB representative. Red Flag PFRs, defined above require the signature of the Project M
25、anager.Technical Rationale:This practice ensures that all problem/failure occurrences including minor glitches are fully reported Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-and dealt with as appropriate in a formal procedure with Project and GSF
26、C management oversight and approval.References1. GSFC Flight Assurance Procedure, No. FAP P-303-849, “Problem/Failure Reporting“2. Guidelines for Standard Payload Assurance Requirements (SPAR) for GSFC Orbital Projects3. The GSFC Certification Log, FAP P-303-8204. Problem Record Items, GSFC, FAP P-3
27、03-8455. NASA NHB 5300.4 (1A-1) ReliabilityProgram Requirements for Aeronautical and Space Systems Contractors (January 1987)6. Reliability Preferred Practice PD-AP-1304, Problem/Failure Report Independent Review/Approval7. Reliability Preferred Practice PD-AP-1305, Risk Rating of Problem/Failure Re
28、ports8. Reliability Preferred Practice PD-ED-1232, Spacecraft Orbital AnomalyReport (SOAR) System9. Reliability Preferred Practice PD-ED-1255, Problem Reporting and Corrective Action SystemProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-refer to D de
29、scriptionD Figure 1. GSFC PFR Form 4-2: Problem/Failure Report (Click on Image for .pdf file) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-refer to D descriptionD Figure 2. GSFC PFR Form 4-2 (cont.): Instruction Sheet for Problem/Failure Report (C
30、lick on image for .pdf file) Impact of Non-Practice: Without this practice with its formal reporting procedures, problems/failures, particularly minor glitches, may be overlooked or not considered serious enough to investigate or report to Project Management. This could result in recurrence of the p
31、roblem/failure during the mission and result in significant degradation in performance.Related Practices: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AAdditional Info: Approval Info: a71 Approval Date: 2000-04-03a71 Approval Name: Eric Raynora71 Approval Organization: QSa71 Approval Phone Number: 202-358-4738Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
