First Edition Dated September, 2000 36
Section 4.4 Acceptance of Key Characteristics Based on
Statistical Process Control (This section is required when
using process data to accept product, but does not alleviate
any engineering requirements mandating 100% inspection.)
When a process has been stabilized and meets the minimum
capability requirement, the supplier may use this section to reduce
the costs associated with inspection processes.
When statistical process control is used as a method for
acceptance of the key characteristic, the following
requirements shall be satisfied:
a. The process shall be in statistical control with variable
data (using appropriate process control charts) before
process capability is calculated.
b. The process shall be capable.
c. The process capability measure used to justify reduced
inspection shall accurately represent the process
fallout rate using industry standard statistical
methods.
d. If the process ceases to be in statistical control, normal
end-item sampling will resume for acceptance of the
product feature until the cause has been identified,
corrected and the process is back in statistical control
and is capable.
Note: The Boeing representative must be notified of this
process implementation prior to incorporation.
Process control and capability data may be used for in-process or final
inspection of Boeing product. Product acceptance may be allowed for a
characteristic produced by a stable and capable process. Non-standard
methods are subject to Boeing approval. Refer to AS9100, Section 4.20.2.
