In: Operations Management
(Operations Management) The following data (in milliliters) are the amount of liquid in the detergent bottles on an automated filling machine. Develop sample mean and sample range control charts using the first 10 samples. Is the process in control? Use the control charts developed in part a to decide if the 11th sample (also given below) indicates an out-of-control situation.
Sample | Obs 1 | Obs 2 | Obs 3 | Obs 4 |
1 | 1,010 | 991 | 985 | 986 |
2 | 995 | 996 | 1,009 | 994 |
3 | 990 | 1,003 | 1,015 | 1,008 |
4 | 1,015 | 1,020 | 1,009 | 998 |
5 | 1,013 | 1,019 | 1,005 | 993 |
6 | 994 | 1,001 | 994 | 1,005 |
7 | 989 | 992 | 982 | 1,020 |
8 | 1,001 | 986 | 996 | 996 |
9 | 1,006 | 989 | 1,005 | 1,007 |
10 | 992 | 1,007 | 1,006 | 979 |
11 |
996 |
1,006 |
997 |
989 |
A2,D3 and D4 are control chart constants
Formula
Sample 11 has sample mean of (996+1006+997+989)/4 = 997 and range of 1006-989 = 17. So sample 11 shows the process is in-control