Chapter 6 Problem A metal fabricator produces connecting rods

Question: #659

1.A metal fabricator produces connecting rods with an outer diameter that has a 1.028±0.04 inch specification. A machine operator takes several sample measurements over time and determines the sample mean outer diameter to be 1.012 inches with a standard deviation of 0.007 inch.

2. Ten samples of 15 parts each were taken from an ongoing process to establish a p chart for control. The samples and the number of defectives in each are shown in the following table:

SAMPLE    n    NUMBER OF
DEFECTS IN
SAMPLE    SAMPLE    n    NUMBER OF
DEFECTS IN
SAMPLE
1    15    3    6             15    0
2    15    0    7             15    2
3    15    1    8             15    3
4    15    3    9             15    2
5    15    2    10         15    2

3.
A shirt manufacturer buys cloth by the 100 yard roll from a supplier. For setting up a control chart to manage the irregularities (e.g., loose threads and tears) the following data was collected from a sample provided by the supplier.


SAMPLE    1    2    3    4    5    6    7    8    9    10
IRREGULARITIES    6    5    6    8    6    4    7    7    7    5

(b)    Suppose the next five rolls from the supplier had nine, two, five, seven and six irregularities. What is the UCL?

(c)    Is the supplier process under control?

Solution: #670

Chapter 6 Problem A metal fabricator produces connecting rods Solution

Calculate the process capability index for this example. 1.143

Explanation:

=1.143
2.
Ten samples of 15 parts each were taken from an ongoing process to establish a p chart for control. The samples and the number of defectives in each are shown in the following table:

SAMPLE n NUMBER OF
DEFECT...