30-09-2013, 04:12 PM
Sampling Inspection
Sampling Inspection.ppt (Size: 958.5 KB / Downloads: 62)
Inspection’s role and type
Although the modern QM emphasizes the principle of prevention in advance, sampling inspection has still its special role, especially in inspecting the quality of raw material, WIP and finished goods.
Inspection: a. no inspection
b. Acceptance sampling
c. 100% inspection
When to use acceptance sampling?
When testing is destructive.
When the cost of 100% inspection is high.
When 100% inspection is not technologically feasible or would require so much calendar time and/or expenses.
When there are many items to be inspected and the inspection error rate is high.
When the vendor has an excellent quality history, and some reduction in inspection from 100% is desired.
When there are potentially serious product liability risks.
Example: Acceptance Sampling Problem
Zypercom, a manufacturer of video interfaces, purchases printed wiring boards from an outside vender, Procard. Procard has set an acceptable quality level of 1% and accepts a 5% risk of rejecting lots at or below this level. Zypercom considers lots with 3% defectives to be unacceptable and will assume a 10% risk of accepting a defective lot.
Develop a sampling plan for Zypercom and determine a rule to be followed by the receiving inspection personnel.