Examine the process output by calculating the control limits and developing X-bar and R control charts using the data given. Does the process look to be in statistical control?

7.2 Problem Set 5

Wells Fargo wants to investigate its loan application processing time. Table below shows the samples that have been taken from 4 branches for 25 random days. Examine the process output by calculating the control limits and developing X-bar and R control charts using the data given. Does the process look to be in statistical control?

Day Branch 1 Branch 2 Branch 3 Branch 4
1 8 12 37 6
2 20 23 33 20
3 24 19 21 10
4 21 16 29 8
5 12 16 24 14
6 25 12 27 11
7 14 21 23 10
8 10 27 39 23
9 23 15 31 20
10 23 8 23 8
11 17 10 26 21
12 24 24 26 24
13 13 14 19 19
14 9 21 24 13
15 12 9 28 22
16 26 11 14 24
17 20 13 18 23
18 5 20 30 7
19 8 13 22 7
20 28 23 35 12
21 25 14 14 20
22 12 11 31 17
23 21 13 17 23
24 14 15 21 16
25 16 13 24 21

Hinge Manufacturing Company employs a Kanban system for a component part. The daily demand is 1000 hinges. Each container has a wait time of 0.08/day, and a processing time of 0.32 days. The Container size is 60 hinges and the safety factor (α) is 12%. (Note that lead-time is the summation of waiting time and processing time.)
Calculate the number of containers.
What is the maximum inventory of this hinge in the system?

GEICO has inspected one hundred insurance claim forms daily for 25 working days. The number of forms with errors are shown in the following Table. Find , σP, and 3-sigma UCL and LCL. Does the process appear to be in statistical control?

Day Number Nonconforming Day Number Nonconforming
1 2 14 2
2 1 15 1
3 0 16 4
4 3 17 0
5 0 18 3
6 1 19 8
7 0 20 1
8 2 21 0
9 0 22 2
10 1 23 0
11 3 24 2
12 0 25 2
13 10