From: Marsh, Darren S.
[marsh@SLAC.Stanford.EDU]
Sent: Wednesday,
September 18, 2002 8:16 AM
To: Nick Virmani
(E-mail); Borden, Thomas; Robert Johnson (E-mail);
Nordby, Martin E.;
Klaisner, Lowell; Hartmut Sadrozinski (E-mail);
Alessandro Brez (E-mail)
Cc: Martin, Jim;
Marcellini, Bob
Subject: Summary of
Tracker Ladder Production Readiness Review
A Tracker Ladder
Production Readiness Production Readiness Review (PRR) was held on September
16, 2002. The purpose of the of PRR was
to show that the Tracker Ladder production will meet the final performance and
interface specification and the required design specification.
The following
individuals were participants in the PRR.
Richard Horn, Systems
Engineering - Committee Chair
Lowell Klaisner, Chief
Engineer - Committee Member
Martin Nordby, Chief
Mechanical Engineer - Committee Member
Nick Virmani, Mission
Assurance - Committee Member
Harmut Sadrozinski,
Tracker Scientist - Committee Member
Darren Marsh, Mission Assurance - Committee Member
Robert Johnson, Tracker
Subsystem Manager
Tom Borden, Tracker
System Engineer
Alessandro Brez - INFN
Development Engineer, Production Supervisor
Completion of the PRR
and resolution of all resulting action items constitutes readiness for
production.
The Tracker Ladder
Production Readiness Review is for product manufactured at G&A Engineering
located in Oricola, Italy. A total of
1850 Tracker Ladders will be manufactured at G&A through January 2004. An additional 850 Ladders will be
manufactured at Mipot S.P.A. in Cormons, Italy through December 2003. Manufacturing activities at Mipot will be
subject to a separate PRR upon completion of pre-production activities
there. Fabrication activities at both
subcontractors is under the direction of Alessandro Brez from INFN.
PRR presentation
material and links for all relevant documentation and subcontractor information
can be obtained at:
http://www-glast.slac.stanford.edu/Tracker-Hardware/readiness/ladder.html
In preparation for the
PRR, a Pre-PRR was held to review and discuss specific details relating to
materials, critical operations and parameters and specific quality
documentation for the ladders. The
action items resulting from the meeting are attached and label "Appendix
A". In addition, comments from
Nick Virmani on LAT-PS-635 (8/13/02 draft), Tracker SSD Ladder Assembly
Procedure, along with the Tracker responses to the comments are attached and
label, "Appendix B".
A Mechanical Parts
Review Board Meeting was held on September 9, 2002 to accept materials utilized
in ladder production. The meeting
minutes from the Mechanical Parts Review Board Meeting will be archived in the
LAT Document Control System once they have been completed.
The following action
items were generated from the Ladder PRR.
1. LAT-DS-594, Ladder Assembly Drawing, needs
to be revised in accordance with an existing action item to change the ladder
overall length tolerance requirement.
2. Robert Johnson will contact Nick Virmani and
discuss the Tracker's responses to Nick's comments on the Ladder Assembly
Procedure and obtain Nick's concurrence on the responses.
3. The committee recommended the continued
refinement and clarification of the Ladder Assembly Procedure to include
details presently delineated in the internal G&A production traveler and to
incorporate any agreed upon actions from previous ladder production review
discussions.
4. All "TBR's" are to be
resolved. The "TBR's"
include: 1) determination of the number
of ladders that may be wire bonded before electrical testing begins, 1)
determination of "major nonconformance" definition to ensure a halt
in production and prompt notification to Alessandro Brez, 3) review pull test
data information and determine if mean value information should be added to
ladder database.
5. G&A is in the process of building 10
ladders to qualify the encapsulation process with encapsulation materials that
are NASA flight approved. A
post-production review of these 10 ladders will take place at the G&A facility
by Alessandro Brez, Tom Borden and Darren Marsh to evaluate the results of the
encapsulation process and review process documentation. Darren Marsh will also follow-up the
supplier survey performed November 2001 to ensure quality procedure controls
(equipment calibration, employee training and qualification, etc.) employed by
G&A are adequate and complied with.
A subset of the PRR
committee will reconvene upon completion of the aforementioned actions to
review production readiness status for flight quality ladders.
Darren S. Marsh
GLAST Large Area
Telescope Project
Stanford Linear
Accelerator Center
2575 Sand Hill Road, M/S
43A
Menlo Park, CA 94025
(650) 926-4577