In: Statistics and Probability
Three (3) companies supply the same part. All three companies operate in-control processes for the single quality characteristic of part-length. All three companies have a mean part-length equal to 17. The "red company" has a part-length standard deviation of 0.29 for the parts they produce. The "blue company" has a part-length standard deviation of 0.37 for the parts they produce. The "green company" has a part-length standard deviation of 0.20 for the parts they produce. The part-length specification has a tolerance span from 16 to 18.
Which company is more capable of meeting the specification? Explain and support your company choice with process capability statistics.