QA concerns about mid tray production

November 25, 2003



LAT QA (Marsh, Cullinan, and Gobin) has concerns about tray assembly processes not being well defined or specified.  It would seem appropriate to include all the processes for tray assembly, non-destructive testing, cleaning, etc. in the Tray Panel Assembly Procedure LAT-PS-01584.  That way the drawings notes can reference LAT-PS-01584 for specific assembly processes.   


LAT QA will need to make sure all of these processes are in place, are reviewed, approved and followed by Plyform.  It is understood Plyform Travelers are considered proprietary (and are in Italian) and cannot be sent to SLAC for review.  Any review of Plyform traveler process documentation will require English translation.


With regards to the action items generated by Robert Johnson, LAT QA provides the following information to clarify and supplement the requirements necessary prior to starting flight production of the Tracker Mid-Tray Panels.


1.  Paragraph 6.3 (Non-Conformance Reporting) of the Tray Panel Assembly Procedure, LAT-PS-01584, is not acceptable.


LAT QA recommends the following nonconformance reporting requirements:




Supplier shall ensure that Tracker Trays that do not conform to requirements are identified and controlled to prevent their unintended use or delivery.  The controls and related responsibilities for dealing with nonconforming tray assemblies shall be defined in a documented procedure.  Supplier's documented procedure shall define the responsibility for review and authority for the disposition of nonconforming product and the process for approving personnel making these decisions.



Nonconformance:  A condition of any article, material or service in which one or more characteristics do not conform to requirements specified in the drawings or specifications as defined herein and other approved procedures.  This includes failures, discrepancies, defects, anomalies, and malfunctions.

Rework: Used when an article can be made to conform to drawing requirements. Detailed instructions must be included or referenced.  Rework is considered routine when it is covered in a released and approved procedure document that is performed on conditions specified in the assembly procedure or organization quality assurance documentation. 

Repair: Used when the nonconforming article, material or service can be corrected to a usable condition, although its condition may not be identical with drawing/specification requirements.  Repair is not permitted without MRB approval.


Major Nonconformance:  Nonconformanes found as a result of test activities, inspection activities, or discrepant product that cannot be used, with or without modification, for its original intent.


Minor Nonconformance:  Nonconformances not classified as major and for which the cause of the nonconformance is fully known and for which immediate action can be taken to correct the deficiency.




The preliminary review process shall be initiated with the identification and documentation of a nonconformance.  A preliminary review shall be the initial step performed by Supplier to determine if the nonconformance is minor and can be reworked to a condition that completely conforms to the drawing or specification requirements.  Note: preliminary review does not negate the requirement to identify, segregate, document, report, and disposition nonconformances.




Supplier's procedures for handling non-conforming-material are to be followed during tray assembly fabrication.  Once any step in the tray assembly process has begun, nonconformances detected shall be documented and reported to INFN and SLAC under the following conditions: 


*  Any time a nonconformance is detected during in-process assembly or inspection activities,

*  A failure of any portion of testing,

*  Any time a nonconformance is detected during final inspection.




Nonconformance reports shall include a detailed description of the nonconformance, the location of the nonconformance (by part number, tray serial number, drawing reference point, hardware reference point, clock location, etc.), and an exact callout of the violation by drawing or specification requirement (including sub-paragraph or illustration number).  It shall also list what type of inspection revealed the discrepant condition, and what, if any, subsequent actions were taken prior to disclosure.  Dimensional violations shall include "should be" and "is" dimensions.  Nonconformance reports shall also document the root cause of the nonconformance and corrective action taken to prevent the root cause from recurring.  All nonconformances reports must be closed before trays can be shipped.




Supplier shall provide management and engineering support to the GLAST LAT Material Review Board (MRB).  The GLAST LAT MRB is chaired by the GLAST LAT Product Assurance Manager and consists of end-item responsible engineers and specialty engineers, as appropriate.  At a minimum, Supplier participation shall include the engineer responsible for the product described herein and a Quality Assurance representative.


Major nonconformances identified during production of flight tray assemblies shall be documented on a Non-Conformance Report and submitted to the GLAST LAT MRB for review and disposition.  All work on the defective item shall cease until the MRB review is complete and work instructions for returning the item to compliance have been established.


2.  Paragraph 6.4 (Independent Source Inspection), of LAT-PS-01584, Tray Assembly Procedure is not acceptable.  LAT QA recommends the following:


An INFN engineer is to be resident at Plyform for tray assembly production activities.  Independent inspections will be performed where identified on the production traveler by INFN.  Independent source inspections will be performed by INFN and SLAC Quality Assurance on a periodic basis.


3.  Paragraph 6.2 (Database and Traveler) of LAT-PS-01584 is not acceptable.


Unless progress has been made, this database is not up and running.  Also, the database is not the traveler.  The traveler contains the required detailed information to manufacturer trays.  The database is a "summary report" of tray manufacturing.  The traveler, drawings, assembly procedure, inspection test reports comprise the documentation that will be reviewed and accepted by Quality Assurance.


4.  The face sheet layup drawing LAT-DS-00049 needs to include note specifying face sheet layup per Tray Panel Assembly Procedure LAT-PS-01584 (this procedure references Plyform's internal processes for face sheet layup).  The current drawing does not reference any controlling documents or processes for face sheet layup.  This is probably the case for the other face sheet drawings also (LAT-DS-00596, -00617, -00618).


Also, to maintain consistency with recent redlines by J. Clinton to LAT-PS-01584, the note on the face sheet drawings needs to be changed to "...perform non destructive evaluation per LAT-PS-01584".


The ESPI Procedure has not been sent out for review or approval (it's not clear if there is an ESPI procedure has been developed).  The ESPI is a "Special Process" and additional controls will be required for this activity (technician training, standard calibration, etc.)


5.  There is no reference to a painting procedure on the closeout wall drawings LAT-DS-00139 and -00140, or the regular tray assembly drawing LAT-DS-00148.  Painting is not included in the process flow chart (Figure 2) of the Tray Panel Assembly Procedure.  Having a drawing note that says "Paint and prime per manufacturers instructions" is not sufficient for the painting process.  The painting process needs to be included in the assembly flow diagram (with reference to the internal painting processes) in the Assembly Procedure -01584, then the notes on the drawings can be changed to state "Prepare, clean and mask indicated surfaces, prime and paint per LAT-PS-01584".


The insert bonding process and installation tools are specified in the Assembly Procedure -01584, but we need to make it clear in the drawing notes on the closeout wall assembly drawings -00139 and -00140 that inserts are to be bonded into the closeout wall prior to painting. 


6.  It appears three is not a documented process in place for grounding tube bonding.  The bonding process to attach the grounding tubes, including any tools and fixtures,  needs to be identified and specified in the Assembly Procedure -01584, and the note for grounding tube bonding on the closeout wall drawings -00139 and -00140 need to specify -01584.


7.  Coupons will be fabricated with each lot of bonded inserts, bonded face sheet/honeycomb assemblies, and final assembled trays per Assembly Procedure -01584.  Coupons are fabricated per ASTM 100299 - is this correct?  Also there is no indication that the samples will be tested for lot verification.  Will these coupons, or some other coupons, be tested as part of lot acceptance?


8.  No cleaning specifications are identified on drawings or in the Assembly Procedure for the tray assembly.  Are there any cleaning processes?  When and how will parts be cleaned during tray assembly?  Is there a vacuum bakeout planned for the trays?  This needs to be defined in the Assembly Procedure and/or on the drawings.


A bakeout procedure has not been developed, reviewed or approved.  There must be a bakeout procedure developed.


9. In section 9.4.6 of the Assembly Procedure, "labeling" of parts is called out.  The drawings call out bag and tag.  If hardware requires identification, DO NOT use labels on hardware; use epoxy ink or an approved engraving process.  This needs to be specified in the Assembly Procedure.


10. After Plyform has completed their portion of tray fabrication work, INFN has additional activities (acceptance, package, handling, and shipping, shake test, bakeout, etc.) to complete the tray fabrication.  It is expected that INFN develop a traveler and procedures for their portion of work and it be approved by the Tracker team.


11. It's not clear all Peer Review RFAs related to Tracker tray's have been submitted and closed (reference LAT Systems Engineering RFA Status Sheet).


12. A final acceptance of the tray's needs to occur.  The documentation package required for this final acceptance is the following.  This End Item Data Package needs to be referenced in the Tray Assembly Procedure (The End Item Data Package is not the INFN tray database).




The following documentation shall be delivered with each production lot of Tracker trays submitted for acceptance:

*     Certificate of Compliance

*     Inspection and Test Reports.

*     Traceability records of parts and tray assemblies.

*     Process travelers shall be available for review at Supplier facilities.

*     Non-conformance Reports shall be available for review at Supplier facilities.

*     Lot traceability and qualification records.

*     MRB reports with disposition.


13.  LAT QA has to assume the design solutions for the aluminum honeycomb grounding and loose carbon particle issues have been reviewed and approved by the appropriate review team.  Confirmation is requested by QA that a design review has occurred.