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Track 2 Session 10
9:20 to 10:30 a.m. Friday June
16, 2006
Lot Acceptance Test Program: A Viable
Alternative for Parts Incoming Inspection
Modern electronic
equipment involves assembly of complex parts, provided by many
original suppliers. Ensuring the quality of these parts is essential
for ensuring the quality of the end product. Yet, classic incoming
inspection that would require physical inspection of the parts
received is practically impossible due to the complexity of the
parts, the excessive cost of testing equipment, and the scarcity of
qualified testing personnel at the point of assembly. For these
reasons, many manufacturers are forced to rely on the outgoing
inspection provided by the supplier, which in many circumstances is
proving to be inadequate for reasons such as lack of knowledge on
the supplier site regarding critical parameters, errors in equipment
settings, or even administrative errors in shipments and deliveries.
Considering that the defective parts are normally associated with
periods in which the manufacturing process was less controlled, it
is expected that the defective parts are not randomly distributed,
but are concentrated in a small number of manufacturing lots.
Identification and rejection of these lots at the incoming
inspection point would significantly improve the supply quality.
Lot acceptance testing is a logical and relatively inexpensive
solution to this problem. With lot acceptance testing, we take a
sample of parts from each lot and verify the variations of certain
parameters that are easy to monitor and are known to correlate to
the critical parameters that are important for the application. In
many cases, the supplier already collects the data required for such
an analysis, and no additional tests are required.
Key Words: Incoming
Inspection, Lot Acceptance Test, Supply Management
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