In this study we try to select the most appropriate garage location in Istanbul. The fuzzy AD and weighted fuzzy AD which is weighted by fuzzy AHP are used for the evaluation. Then the results of both methods are compared. The methodology is applied for garage location selection in both of European Side and Asian Side of Istanbul separately. The alternative garage locations and the evaluation criteria are identified according to the experts' opinions in IETT.
The alternative areas that are proposed by experts are Beylikdüzü, Arnavutköy, and Silivri in the European Side and Pendik, Sultanbeyli, and Tuzla in Asian Side of Istanbul. The number of main-criteria that we use to solve the problem is six and the number of subcriteria is eighteen. The descriptions of criteria are shown in Table 3.
Table 3 The description of the criteria.
Main criteria |
Subcriteria |
Description |
|
Cost - C1 |
C11 - Investment cost |
The total cost that is necessary for setting up the garage |
C12 - Spare parts transportation cost |
The cost to transfer the spare parts from their suppliers to the garages |
C13 - Vehicle transport cost |
The cost that occurs when a bus travels without passengers to go to the garage or to the start of the lines |
C14 - Operation cost |
The total maintenance, cleaning, and other operations’ cost |
|
Infrastructure - C2 |
C21 - Municipality services |
Electric, water, and gas requirements supply from municipality |
C22 - Technological infrastructure |
The infrastructure for telecommunication and internet supply |
|
Social and economic structure - C3 |
C31 - Population structure |
The density of the population in the regions |
C32 - Urbanization of the region |
The immigration to the region and the population increase rate |
C33 - Neighborhood response |
The response of the neighborhood when a new garage is set up |
C34 - Behavior of the passengers |
The satisfaction degree of the passengers who live around the new garage |
|
Macro factors - C4 |
C41 - Government policy |
The taxes and incentives |
C42 - Reconstruction and building plans |
The features of the garage building |
|
Environmental factors - C5 |
C51 - Effects on the open land |
The effect of the new garage on the social/urban life |
C52 - Convenience of the land |
The grade of the land, stream bed situation, and earthquake risk |
C53 - Effect on people's health |
The effect of the new garage on human health because of the exhaust, dust, smell, and so forth |
|
Accessibility - C6 |
C61 - Proximity to common service areas |
The proximity of the new garage to the common service areas is important to decrease the dead kilometers |
C62 - Proximity to the other garages |
The proximity of the new garage to the other garages is important to take service when a problem occurred in the new garage |
C63 - Proximity to the main roads |
The proximity to the main roads is important to decrease the spare parts transportation cost and vehicle transport cost |
|
Firstly we determine the weights of main and subcriteria by using the Buckley's fuzzy AHP methodology. In the first stage of this methodology, the pairwise comparisons of main and subcriteria are made by experts. The pairwise comparison matrix of main criteria is shown in Table 4. After main criteria comparisons, subcriteria comparisons are made and the weights of all criteria are calculated. The results are shown in Table 5.
Table 4 The main criteria of pairwise comparison matrix.
|
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
|
C1 |
(1.00 |
1 |
1.00) |
(0.25 |
0.33 |
0.50) |
(2.00 |
3 |
4.00) |
(0.25 |
0.33 |
0.50) |
(0.33 |
0.5 |
1.00) |
(0.20 |
0.25 |
0.33) |
C2 |
(2.00 |
3 |
4.00) |
(1.00 |
1 |
1.00) |
(4.00 |
5 |
6.00) |
(4.00 |
5 |
6.00) |
(6.00 |
7 |
8.00) |
(0.20 |
0.25 |
0.33) |
C3 |
(0.25 |
0.33 |
0.50) |
(0.17 |
0.2 |
0.25) |
(1.00 |
1 |
1.00) |
(1.00 |
1 |
2.00) |
(0.25 |
0.33 |
0.50) |
(0.25 |
0.33 |
0.50) |
C4 |
(2.00 |
3 |
4.00) |
(0.17 |
0.2 |
0.25) |
(0.50 |
1 |
1.00) |
(1.00 |
1 |
1.00) |
(0.25 |
0.33 |
0.50) |
(0.20 |
0.25 |
0.33) |
C5 |
(2.00 |
3 |
4.00) |
(0.13 |
0.14 |
0.17) |
(2.00 |
3 |
4.00) |
(2.00 |
3 |
4.00) |
(1.00 |
1 |
1.00) |
(0.20 |
0.25 |
0.33) |
C6 |
(3.00 |
4 |
5.00) |
(3.00 |
4 |
5.00) |
(2.00 |
3 |
4.00) |
(3.00 |
4 |
5.00) |
Table 5 The criteria weights found by fuzzy AHP.
|
Cost |
Infrastructure |
Social and economic structure |
Macrofactors |
Environmental factors |
Accessibility |
|
C11 |
C12 |
C13 |
C14 |
C21 |
C22 |
C31 |
C32 |
C33 |
C34 |
C41 |
C42 |
C51 |
C52 |
C53 |
C61 |
C62 |
C63 |
|
Main criteria weights |
0.077 |
0.077 |
0.077 |
0.077 |
0.353 |
0.353 |
0.052 |
0.052 |
0.052 |
0.052 |
0.073 |
0.073 |
0.133 |
0.133 |
0.133 |
0.388 |
0.388 |
0.388 |
Subcriteria weights |
0.270 |
0.040 |
0.632 |
0.075 |
0.843 |
0.171 |
0.177 |
0.680 |
0.089 |
0.088 |
0.843 |
0.171 |
0.117 |
0.081 |
0.880 |
0.348 |
0.054 |
0.495 |
|
After determining the weights of the criteria, we apply the AD manually to find final decision. We use crisp AD for the "Cost" main criterion and fuzzy AD for other main criteria.
The system and design range are identified by experts in IETT to implement the AD methodology for European and Asian Side of Istanbul as shown in Tables 6 and 7, respectively.
Table 6 The system and design range for European Side of Istanbul.
|
System range |
Design range |
Beylikdüzü |
Arnavutköy |
Silivri |
|
C11 |
55,000,000–65,000,000 |
34,000,000–35,000,000 |
40,000,000–45,000,000 |
30,000,00–60,000,000 |
C12 |
250,000–300,000 |
175,000–200,000 |
375,000–450,000 |
150,000–400,000 |
C13 |
1,250,000–1,500,000 |
800,000–1,000,000 |
2,300,000–2,500,000 |
900,000–2,400,000 |
C14 |
4,700,000–4,950,000 |
7,200,000–7,425,000 |
12,000,000–12,375,000 |
4,500,000–12,250,000 |
C21 |
8, 11, 14 |
8, 11, 14 |
8, 11, 14 |
minimum 12 |
C22 |
4, 7, 10 |
8, 11, 14 |
4, 7, 10 |
minimum 8 |
C31 |
4, 7, 10 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C32 |
4, 7, 10 |
12, 15, 18 |
8, 11, 14 |
minimum 8 |
C33 |
12, 15, 18 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C34 |
8, 11, 14 |
8, 11, 14 |
8, 11, 14 |
minimum 4 |
C41 |
8, 11, 14 |
8, 11, 14 |
12, 15, 18 |
minimum 12 |
C42 |
4, 7, 10 |
12, 15, 18 |
12, 15, 18 |
minimum 8 |
C51 |
4, 7, 10 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C52 |
4, 7, 10 |
12, 15, 18 |
8, 11, 14 |
minimum 8 |
C53 |
4, 7, 10 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C61 |
8, 11, 14 |
8, 11, 14 |
4, 7, 10 |
minimum 8 |
C62 |
8, 11, 14 |
12, 15, 18 |
4, 7, 10 |
minimum 8 |
C63 |
8, 11, 14 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
|
Table 7 The system and design range for Asian Side of Istanbul.
Asian Side alternatives |
|
System range |
Design range |
Pendik |
Sultanbeyli |
Tuzla |
|
C11 |
50,000,000–60,000,000 |
30,000,000–31,000,000 |
39,000,000–43,000,000 |
30,000,00–60,000,000 |
C12 |
50,000–55,000 |
55,000–75,000 |
32,000–37,000 |
30,000–80,000 |
C13 |
750,000–950,000 |
780,000–1,000,000 |
1,000,000–1,150,000 |
700,000–1,300,000 |
C14 |
4,700,000–4,950,000 |
5,800,000–600,000 |
8,800,000–9,000,000 |
4,500,000–10,000,000 |
C21 |
8, 11, 14 |
8, 11, 14 |
8, 11, 14 |
minimum 12 |
C22 |
8, 11, 14 |
4, 7, 10 |
4, 7, 10 |
minimum 8 |
C31 |
4, 7, 10 |
4, 7, 10 |
8, 11, 14 |
minimum 8 |
C32 |
8, 11, 14 |
12, 15, 18 |
12, 15, 18 |
minimum 8 |
C33 |
4, 7, 10 |
12, 15, 18 |
8, 11, 14 |
minimum 8 |
C34 |
8, 11, 14 |
8, 11, 14 |
8, 11, 14 |
minimum 4 |
C41 |
8, 11, 14 |
12, 15, 18 |
12, 15, 18 |
minimum 12 |
C42 |
8, 11, 14 |
12, 15, 18 |
4, 7, 10 |
minimum 8 |
C51 |
4, 7, 10 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C52 |
8, 11, 14 |
12, 15, 18 |
4, 7, 10 |
minimum 8 |
C53 |
4, 7, 10 |
8, 11, 14 |
8, 11, 14 |
minimum 8 |
C61 |
8, 11, 14 |
8, 11, 14 |
4, 7, 10 |
minimum 8 |
C62 |
4, 7, 10 |
12, 15, 18 |
4, 7, 10 |
minimum 8 |
C63 |
12, 15, 18 |
8, 11, 14 |
12, 15, 18 |
minimum 8 |
In the first stage of AD, we make the calculations without the criteria weights. The triangular fuzzy numbers for intangible factors are excellent (16, 20, 20), very good (12, 15, 18), good (8, 11, 14) , fair (4, 7, 10), and poor (0, 0, 6). The results of unweighted fuzzy axiomatic design (Tables 8 and 9) show that the alternative "Arnavutköy" for the European Side of Istanbul and the alternative "Sultanbeyli" for the Asian Side of Istanbul are selected as the new garage locations because they have the minimum information contents.
Table 8 Unit Index for unweighted information contents for European Side of Istanbul.
Alternatives |
I1
|
I2
|
I3
|
I4
|
I5 |
I6 |
Total |
Beylikdüzü |
0.250 |
4.407 |
3.354 |
4.407 |
5.492 |
2.322 |
20.231 |
Arnavutköy |
0.250 |
2.822 |
1.769 |
2.822 |
1.980 |
1.980
|
11.622* |
Silivri
|
0.792 |
4.407 |
2.025 |
1.292 |
1.980 |
4.435 |
14.932 |
*refers the most appropriate alternatives for the location selection.
Table 9 Unit Index for unweighted information contents for Asian Side of Istanbul.
Alternatives |
I1
|
I2
|
I3
|
I4
|
I5 |
I6 |
Total |
Pendik |
0.000 |
2.822 |
3.610
|
2.822 |
4.435
|
3.036
|
16.726
|
Sultanbeyli |
0.000 |
4.407
|
2.305
|
1.292
|
1.980
|
1.980
|
11.964* |
Tuzla
|
0.000 |
4.407 |
1.769
|
3.391
|
3.379
|
4.093
|
17.038
|
*refers the most appropriate alternatives for the location selection.
Experts examined that weights of criteria are not equal, so that weighted AD is used to find out realistic result. In the second stage, weighted fuzzy AD calculations are made and the weights which are calculated in fuzzy AHP are taken into account. The results in Tables 10 and 11 are obtained.
Table 10 Unit Index for weighted information contents for European Side of Istanbul.
Alternatives |
I1
|
I2
|
I3
|
I4
|
I5 |
I6 |
Total |
Beylikdüzü |
0.000 |
1.287 |
1.026
|
1.054
|
1.116
|
1.108
|
5.591
|
Arnavutköy |
0.000 |
1.266
|
1.005
|
1.050
|
1.047
|
1.104
|
5.473* |
Silivri
|
0.000 |
1.287
|
1.012
|
1.010
|
1.046
|
1.163
|
5.517
|
*refers the most appropriate alternatives for the location selection.
Table 11 Unit Index for weighted information contents for Asian Side of Istanbul.
Alternatives |
I1
|
I2
|
I3
|
I4
|
I5 |
I6 |
Total |
Pendik |
0.0 |
1.266
|
1.015
|
1.050
|
1.115
|
1.070
|
5.516
|
Sultanbeyli |
0.0 |
1.287
|
1.007
|
1.010
|
1.047
|
1.104
|
5.455* |
Tuzla
|
0.0 |
1.287
|
1.005
|
1.019
|
1.051
|
1.123
|
5.485
|
*refers the most appropriate alternatives for the location selection.
Results of weighted axiomatic design show that the alternative "Arnavutköy" for the European Side of Istanbul and the alternative "Sultanbeyli" for the Asian Side of Istanbul are selected as the new garage locations because they have the minimum information contents.