Question

EK Chemical Company sells a specially formulated compound that contains an active ingredient X. Such compound is packed in packages marked to have 14 mg of X. In reality, EK has set the mean content of X at -0.5 mg off the marked specification, and the process currently has a standard deviation of 2.9 mg. Suppose the customer will accept any boxes as long as the content of X is anywhere between +/- 2.9 from the specification of 14 mg but not exceeding the upper tolerance limit. It is necessary that 99.7% of the products delivered have to comply with the requirements. Of the two process capability index values (i.e. the LHS and RHS ratios), what is the appropriate numeric value that is relevant in this case?

Answer 1

Case 1:

Case 2

The values of Cp and Cpk of Case 2 will be considered relevant.