Specifically, the priority in addressing the issues is revealed as follows: 1 -- Breaking of the needles

2 -- Skipping the stitches

3 -- the low air pressure

4 -- the stuck of the pedal

4 -- Other causes

5 -- the breaking of the thread, and last

6 -- the dull knife.

3. CP and CPK values

A recent article in Quality Engineering revealed the various figures associated with the compactibility of sand; according to the author of the article, the values varied between 38 and 46, meaning otherwise that the lowest value of sand compactibility was of 38 and its highest value was of 46.

In this context, it is useful to calculate the Cp and the Cpk for the sand compactibility. Both Cp and Cpk are concepts pertaining to the Six Sigma principles and they are used in correlation to the capability of processes. When used in correlation to each other, the Cp and the Cpk can help the researcher form an objective and informed opinion...

More importantly, they also help identify any potential issue that might exist throughout the process and as such, constitute grounds for future improvement endeavors.
From a mathematical standpoint, the Cp and the Cpk can be computed with the aid of the following formulas:

Cp = (USL -- LSL) / 6 x Standard deviation (within)

Cpk = Min (Cpl, Cpu)

Where:

Cpl = (mu - LSL) / 3 x standard deviation (within), and Cpu = (USL - mu) / 3 x standard deviation (within) (LSS Academy).

USL = 46

LSL = 38

mu = ( 38 + 46 ) / 2 = 42

Standard deviation = 4

Cp = ( 46 -- 38 ) / 6 x 4 = 8 / 6 x 4 = 5.33

Cpu = ( 42 -- 36 ) / 3 x 4 = 6 / 3 x 4 = 8

Cpk = ( 46 -- 42 ) / 3 x 4 = 4 / 3 x 4 = 5.33

Cpk = Min (8; 5.33) = 5.33

Ultimately then, both Cp and Cpk have the equal value of 5.33, revealing a satisfactory quality of the…