A process capability index of 2 means that the upper and lower specification limits of the process are six standard deviations above and below the mean respectively. True or False? Eliminating variations is always possible. True or False?

True

Explanation:

The formula to compute the process capability index is shown below:

Cpk = minimum [(Mean - LSL) ÷ 3σ , (USL – Mean) ÷ 3σ]

Now

If Cpk = 2,

so  

(Mean - LSL) ÷ 3σ = 2 or (USL – Mean) ÷ 3σ = 2

Mean – LSL = 6σ or USL – Mean = 6σ

Therefore, if Cpk = 2, the process's USL or LSL is six standard deviations (6σ) up or down mean

Hence, the given statement is true

answer; specific performance;

answer; the above statement/question is ( true);