Test/Diagnosis/Rework Process Problems

Using the Test/Diagnosis/Rework Process Step Calculator solve the following problems:

Problem 1

Starting with the default data set loaded into the calculator, the diagnosis fraction set to 0% and the diagnosis cost set to 0 (i.e., all parts that do not pass the test will be scrapped), answer the following questions:   

a) If the incoming yield is decreased from 90% to 85%, what should happen to the outgoing yield?  Qualitatively, explain why.

b) If the fault coverage is increased to 100%, what effect does decreasing the incoming yield from 90% to 85% have?

c) Why does a change in the false positive fraction from affects all to affects only good parts change the outgoing yield?

Problem 2

Using the default data set, is the yielded cost resulting from the test/diagnosis/rework process greater when false positives are created on only good parts or when false positives are created on all parts:

a) When there is no rework?

b) When there are many rework attempts?

c) Can you qualitatively explain the result in parts a) and b)?

Problem 3

Using the Monte Carlo analysis (see help page with the calculator) and the default data set,

a) Plot the out going yielded cost as a function of Monte Carlo sample size.

b) How many samples should be used for the default analysis?

b) What parameters in the model affect the minimum sample size?