Qualitative sampling methods
I. General
1, the formulation of purpose
In order to save the cost of inspection, effective control of raw materials, finished goods quality are formulated.
2, the scope
The company's quality control unit to perform a variety of sampling operations to be conducted in accordance Measures.
Second, the operating rules
1, the sampling plan
Single sampling of the company's quality inspection sampling plans using MIL-STD-105E, II-class general inspection and special inspection level of S-4.
2, the test principle
(1) of the company's quality inspection sampling plans with special provisions for single use normal inspection.
(2) Inspection For adjustment, quality executives should be approved before the change.
3, inspection Conversion Description
(1) conversion of the approval process
(A) by the quality department tightened, relaxed or restore the application of the normal inspection and approval of the quality executives.
(B) proposed to relax or to restore the normal application of inspection by the inspection unit, the approval of the quality executives.
(C) by the quality executives indicate tightened for some tests, relaxing or restore normal inspection implemented by the quality department.
(2) IQC check experienced table "was recognized in the following situations need to report to the quality manager.
(A) random checks for more than five consecutive batches qualified.
(B) to confirm a check for more than five consecutive batches qualified.
(C) Recognition pass the inspection.
(3) conversion by normal inspection standards tightened inspection standards
In the normal inspection process, is determined more than five consecutive batches the unqualified, quality can apply to switch to tightened inspection standards.
(4) by the tightened inspection standards converted to a normal level of inspection conditions
In the the tightened inspection process, continuous inspection five batches are determining eligibility, quality can switch to normal inspection levels way.
(5), converted to the conditions of the special inspection levels by normal inspection level
In the normal inspection process, continuous inspection in five batches for determining eligibility, and extracted samples, no major flaws (MA) and a fatal flaw (CR), the Quality Department proposed the application of the special inspection level inspection or inspection unit .
(6), by the special inspection levels normal inspection level
Special inspection level inspection process, as long as a group is judged unqualified, quality should be reported to the quality manager identified restore normal inspection.
Full inspection timing
In the following circumstances, the approval of the quality executives should be used to the full inspection:
The fatal flaw (CR) (1) inspection of materials (finished).
(2) safety defects or hidden quality problems.
(3) storage testing and process for a long time of bad comparison.
(4) The quality is very unstable.
(5) Other necessary to implement a full inspection.
