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Unformatted text preview: between various city pairs, as shown below. Formulate and solve a network optimization model to find the quickest route from Seattle to Denver? Seattle
Butte Billings 10 3 4 9
Portland 7
7 7 7 12 Boise
14 6 Cheyenne
7 Salt Lake
City 1 5
Grand
Junction 4 Denver This is a shortest path problem. To set up a spreadsheet model, first list all of the arcs as shown in B4:C11, along with their capacity (F4). Only the arc from F1 to WH1 is capacitated. Then list all of the nodes as shown in I4:I11 along with each node’s supply or demand (L4:L11). B
3
4
5
6
7
8
9
10
11 C From
F1
F1
F2
WH1
WH1
WH2
WH2
WH2 To
WH1
WH2
WH2
WS1
WS2
WS2
WS3
WS4 D E F G Capacity
250 Unit Cost
$40
$35
$25
$60
$35
$55
$50
$65 H I Nodes
F1
F2
WH1
WH2
WS1
WS2
WS3
WS4 JK L Supply/Demand
400
250
0
0
200
100
150
200 The changing cells are the amount of flow to send through each arc. These are shown in Flow (D4:D11) below, with an arbitrary value of 10 entered for each. The flow through the arc from F1 to WH1 must be less than the capacity of 250, as indicated by the constraint D4 <= F4. 10 B
3
4
5
6
7
8
9
10
11 C D From
F1
F1
F2
WH1
WH1
WH2
WH2
WH2 To
WH1
WH2
WH2
WS1
WS2
WS2
WS3
WS4 Flow
10
10
10
10
10
10
10
10 E F <= Capacity
250 G Unit Cost
$40
$35
$25
$60
$35
$55
$50
$65 For each node, calculate the net flow as a function of the changing cells. This can be done using the SUMIF function. In each case, the first SUMIF function calculates the flow leaving the node and the second one calculates the flow entering the node. For example, consider the F1 node (I4). SUMIF(From, I4, Flow) sums each individual entry in Flow (the changing cells in D4:D11) if that entry is in a row where the entry in From (B4:B11) is the same as in I4 (i.e., F1). Since I4 = F1 and the only rows that have F1 in From (B4:B11) are rows 4 and 5, the sum in the ship column is only over these same rows, so this sum is D4+D5. B
3
4
5
6
7
8
9
10
11 C D From
F1
F1
F2
WH1
WH1
WH2
WH2
WH2 To
WH1
WH2
WH2
WS1
WS2
WS2
WS3
WS4 Flow
10
10
10
10
10
10
10
10 E F G <= Capacity
250 Unit Cost
$40
$35
$25
$60
$35
$55
$50
$65 H I J Nodes
F1
F2
WH1
WH2
WS1
WS2
WS3
WS4 Net Flow
20
10
10
10
10
20
10
10 K L =
=
=
=
=
=
=
= Supply/Demand
400
250
0
0
200
100
150
200 J 3
4
5
6
7
8
9
10
11 Net Flow
=SUMIF(From,Nodes,Flow)SUMIF(To,Nodes,Flow)
=SUMIF(From,Nodes,Flow)SUMIF(To,Nodes,Flow)
=SUMIF(From,Nodes,Flow)SUMIF(To,Nodes,Flow)
=SUMIF(From,Nodes,Flow)SUMIF(To,Nodes,Flow)
=SUMIF(From,Nodes,Flow)SUMIF(To,Nodes,Flow)
=SUMIF(From,Nodes,Flow)SUM...
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This document was uploaded on 01/31/2014.
 Winter '14
 Finance

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