Problem 4.13 (15 pts) A DUT can be sold for $1.25 if it passes all of its tests.
ID: 2581774 • Letter: P
Question
Problem 4.13 (15 pts) A DUT can be sold for $1.25 if it passes all of its tests. If it does not pass all of its tests, it cannot be sold at all. Assume that amore repeatable DC offset measurement is used resulting in a narrower guardband requirement causes the production yield to rise from 92% to 98%. Also assume that the cost of testing is known to be 3.5 cents per second and that the more repeatable DC offset measurement adds 250 msec to the test time. Does the extra yield obtained with the more repeatable measurement justify the extra cost associated with testing?Explanation / Answer
In the given case, let us assume 100% capacity is 100 units. After the usage of a more repeatable DC offset measurement the capacity increases from 92 units (92%) to 98 units (98%), which increases 6 units in total capacity. The benefit is the Sale price of these 6 units. Sale price of 6 units is 6 units X $1.25 = $ 7.5.
Let us see about the cost part:
Since more repeatable DC offset measurement is used, it increases the testing time for every unit by 250 milli seconds. I.e., testing time increases by 1 second for every 4 units. For testing 100 units, increase in testing time is 25 seconds. Cost of testing for increase = 25 sec X 3.5 cents per second = 87.5 cents = $0.875.
Therefore, the net benefit = 7.5 - 0.875 = $ 6.625. Yes installation of repeatable DC offset measurement justifies the increase in cost of testing charges, since the net benefit is positive.