BUS606: Operations and Supply Chain Management

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

	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.

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

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.
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.