Solutions Operations management

Samples of 12-volt batteries are taken at 30-minute intervals during a production run. Each sample c

Question: Samples of 12-volt batteries are taken at 30-minute intervals during a production run. Each sample consists of 3 batteries, and a technician records how long each battery will produce 400 amperes during a standard test. Given the following data, construct 3-sigma mean and range control charts and evaluate whether the process is in control.

Minutes	Sample	Battery1	Battery2	Battery3
13.3	1	13.3	9.4	12.1
9.4	2	12.2	13.4	8.5
12.1	3	11.2	8.2	9.2
12.2	4	7.8	9.7	10.0
13.4	5	10.1	11.4	13.8
8.5	6	9.9	11.7	8.5
11.2
8.2
9.2
7.8
9.7
10.0
10.1
11.4
13.8
9.9
11.7
8.5