The long-range planning department for the Ohio Trust Company is considering expanding its operation into a 88-county
Question:
The long-range planning department for the Ohio Trust Company is considering expanding its operation into a 88-county region in northeastern Ohio. Currently, Ohio Trust does not have a principal place of business in any of the 88 counties. According to the banking laws in Ohio, if a bank establishes a principal place of business (PPB) in any county, branch banks can be established in that county and in any adjacent county. However, to establish a new principal place of business, Ohio Trust must either obtain approval for a new bank from the state's superintendent of banks or purchase an existing bank.
The following table lists the 88 counties in the region and adjacent counties. For example, County 1 is adjacent to 2, 18, and 19 counties; County 18 is adjacent to 1, 19, 20, 21, 22, 17, 3 and 2 counties; and so on.
Counties Under Consideration | Adjacent Counties (by Number) |
1 | 2, 18, 19 |
2 | 1, 3, 17, 18 |
3 | 2, 4, 16, 17 |
4 | 3, 5, 15, 16, 17 |
5 | 4, 6, 15 |
6 | 5, 7, 12, 13, 14, 15 |
7 | 6, 8, 12 |
8 | 7, 9, 11, 12 |
9 | 8, 10, 11 |
10 | 9, 11, 28, 29 |
11 | 8, 9, 10, 12, 27, 28, 29 |
12 | 6, 7, 8, 11, 13, 27 |
13 | 6, 12, 14, 25, 26 |
14 | 6, 13, 15, 24, 25 |
15 | 4, 5, 6, 14, 16, 23, 24 |
16 | 4, 15, 17, 22, 23 |
17 | 2, 3, 4, 16, 18, 21, 22 |
18 | 1, 2, 17, 19, 20, 21, 22 |
19 | 1, 18, 20 |
20 | 18, 19, 21, 39 |
21 | 17, 18, 20, 22, 37, 38, 39 |
22 | 16, 17, 18, 21, 23, 36, 37 |
23 | 15, 16, 22, 24, 34, 35, 36 |
24 | 14, 15, 23, 25, 34 |
25 | 13, 14, 24, 26, 33, 34 |
26 | 12, 13, 25, 27, 33 |
27 | 11, 12, 26, 28, 32, 33 |
28 | 10, 11, 27, 29, 31, 32 |
29 | 10, 11, 28, 30, 31 |
30 | 29, 31, 48, 49 |
31 | 28, 29, 30, 32, 47, 48 |
32 | 27, 28, 31, 33, 46, 47 |
33 | 25, 26, 27, 32, 34, 45, 46 |
34 | 23, 24, 25, 33, 35, 44, 45 |
35 | 23, 34, 36, 42, 43, 44 |
36 | 22, 23, 35, 37, 42 |
37 | 21, 22, 36, 38, 41, 42 |
38 | 21, 37, 39, 40, 41 |
39 | 20, 21, 38, 40 |
40 | 38, 39, 41, 58 |
41 | 37, 38, 40, 42, 57, 58, 59 |
42 | 35, 36, 37, 41, 43, 57 |
43 | 35, 42, 44, 56, 57 |
44 | 34, 35, 43, 45, 55, 56 |
45 | 33, 34, 44, 46, 54, 55 |
46 | 32, 33, 45, 47, 53, 54 |
47 | 31, 32, 46, 48, 51, 52, 53 |
48 | 30, 31, 47, 49, 51 |
49 | 30, 48, 50, 51 |
50 | 49, 51, 70 |
51 | 47, 48, 49, 50, 52, 70 |
52 | 47, 51, 53, 68, 69, 70 |
53 | 46, 47, 52, 54, 66, 68 |
54 | 45, 46, 53, 55, 66 |
55 | 44, 45, 54, 56, 64, 65, 66 |
56 | 43, 44, 55, 57, 59, 63, 64 |
57 | 41, 42, 43, 56, 59 |
58 | 40, 41, 59, 60, 61 |
59 | 41, 56, 57, 58, 61, 62, 63 |
60 | 58, 61, 76, 77, 78, 79 |
61 | 58, 59, 60, 62, 76 |
62 | 59, 61, 63, 74, 75, 76 |
63 | 56, 59, 62, 64, 74, 75 |
64 | 55, 56, 63, 65, 73, 74 |
65 | 55, 64, 66, 67, 72, 73 |
66 | 53, 54, 55, 65, 67, 68 |
67 | 65, 66, 68, 71, 72 |
68 | 52, 53, 66, 67, 69, 71 |
69 | 52, 68, 70 |
70 | 50, 51, 52, 69 |
71 | 67, 68, 72, 88 |
72 | 65, 67, 71, 73, 87, 88 |
73 | 64, 65, 72, 74, 85, 87, 88 |
74 | 63, 64, 73, 75, 84, 85 |
75 | 62, 63, 74, 76, 77, 82, 83, 84 |
76 | 60, 61, 62, 75, 77, 78 |
77 | 75, 76, 78, 81, 82 |
78 | 60, 76, 77, 79, 80, 81 |
79 | 60, 78, 80 |
80 | 78, 79, 81 |
81 | 77, 78, 80, 82 |
82 | 75, 77, 81, 83 |
83 | 75, 82, 84, 86 |
84 | 74, 75, 83, 85, 86 |
85 | 73, 74, 84, 86, 87 |
86 | 83, 84, 85, 87 |
87 | 72, 73, 85, 86, 88 |
88 | 71, 72, 87 |
Consider the model to find the location of required principal places of business (PPBs) to minimize the number of PPBs needed to open all counties to branches.
Let xj = 1 if place a PBB in county j, 0 if not; j = 1, 2,...,88
Min | x1 + x2 + x3 + ... + x88 | |||
s.t. | ||||
x1 + x2 + x18 + x19 | ≥ | 1 | County 1 | |
x1 + x2 + x3 + x17 + x18 | ≥ | 1 | County 2 | |
x71 + x72 + x87 + x88 | ≥ | 1 | County 88 |