An employee of ABC Inc., takes samples of 6 items from the service line at regular intervals. He notes down X bar and R values for each sample. After going through 60 groups of 6 samples each, he gets X bar =50 and R-bar=5. Suppose normality.
a) Determine the control limits for X bar and R chart? Determine whether all the points fall in these limits.
b) Find out the mean and standard deviation for the procedure. Also, compute the ±3 standard deviation limits for individual data.
c) If the specification data was 51+6, describe your inference on the ability of the procedure to produce in these specifications.