Application of control charts to small lot acceptance

Advances in air technology have resulted in increased cartridge performance requirements which are crowding the present "state of the art" design performance. Process control, which would seem mandatory, is not implemented by contractors for several justifiable reasons. Further, because production lots are small and infrequent, and because destructive testing is involved; the problem of confidence level and minimum sample size becomes paramount in acceptance tests. The use of control charts in production acceptance tests by the Government can provide:

1. additional confidence in lot acceptance because additional information is available

2. valuable information feedback to the design engineer and contractor for the resolution of design and production problems

3. partial lot acceptance.

Control charting could be readily incorporated into current cartridge production lot acceptance procedures where MIL-STD-IOSD is employed with variables datao Cartridge serialization and production records would be the only additional requirements.