. A standard of 0.3 ppm has been estab- lished for formaldehyde emission levels in wood products....
Question:
.
A standard of 0.3 ppm has been estab-
lished for formaldehyde emission levels in wood products. Suppose that the stan-
dard deviation of emissions in an indi-
vidual board is o = 0.10 ppm. Any lot that contains 1% of its items above 0.3 ppm is considered acceptable, Any lot that has 8% or more of its items above 0.3 ppm is considered unacceptable.
Good lots are to be accepted with prob-
ability 0.95, 'and bad lots are to be rejected with probability 0.90.
(a) Derive a variables sampling plan for this situation.
(b) Using the 1% nonconformance level as an AQL, and assuming that lots consist of 5000 panels, find an appropriate set of sampling plans from MIL STD 414, assuming q unknown. Compare the sample sizes and the protection that both producer and consumer obtain from this plan with the plan derived in part (a).
(e) Find an attributes sampling plan that has the same OC curve as the vari-
ables sampling plan derived in part
(a). Compare the sample sizes
* required for equivalent protection.
Under what circumstances would variables sampling be more eco-
nomically efficient?
(d) Using the 1% nonconforming as an AQL, find an attributes sampling plan from MIL STD 105E. Compare the sample sizes and the protection obtained from this plan with the plans derived in parts (a). (b), and (c).
Step by Step Answer:
Introduction To Statistical Quality Control
ISBN: 9780471656319
5th Edition
Authors: Douglas C. Montgomery