Question

The following list shows processes, their standard deviations, and the job specifications (+/- indicates that the outcome may be within that interval of a design value; for example, say we have +/- 0.5 inches; if the design value was 20 inches, then the specifications are 19.5 to 20.5 inches)

process	standard deviation (inches)	job specification (+/- inches)
1	0.02	0.05
2	0.04	0.07
3	0.10	0.18
4	0.05	0.15
5	0.01	0.04

Which of these process are capable of performing their given jobs? (Here let us say that a process is capable if Cp is at least 1)

		1 and 5
		2 and 4
		2 and 3
		4 and 5

Answer 1

Process	StDev	Spec	Cp = 2*Spec / (6*Sigma)
1	0.02	0.05	0.833
2	0.04	0.07	0.583
3	0.10	0.18	0.600
4	0.05	0.15	1.000
5	0.01	0.04	1.333

We find that the C_p for Job 4 and 5 are more than 1.0.

So,

The correct answer is:

4 and 5