Determination Of Distribution Center Location In Xyz Small And Medium Enterprise (Sme) Using Center Of Gravity Method

: XYZ Small Medium Enterprise (SME) is an SME that produces hijab. Research activities on XYZ aims to determine the operational cost of XYZ, caused by the far distance between the production site with retails. The analytical method which we use is by using the Center of Gravity. From the results of using the Center of Gravity method, the location of the new warehouse can be determined with the coordinates X = -7.51, Y = 110.45, which is located in Dusun II, Lencoh, Selo, Boyolali Regency, Central Java, XYZ can save distribution operational cost from IDR 22,711,150 to IDR 12,712,400. Therefore, XYZ can save distribution operational costs of IDR 9,998,750 or with a percentage of 55.97%. With the new distribution center location, it will shorten the distance from 1446 km to 264.6 km and reduce the transportation cost from the production site in Cicalengka, Bandung to the distribution center located in Dusun II, Lencoh, Selo, Boyolali Regency, Central Java.


Introduction
Logistics is about planning and controlling the flow of material and information in an organization in both public and private sectors (Ghiani, Laporte, & Musmanno, 2004).Distribution is the activity of delivering products from producers to consumers as end users (Kotler, Saliba, & Bruce, 1991; Antoni et al., 2019).Distribution activities are important in manufacturing to create an integrated system from a single location point to another location point.The farther the distance distribution activities will cause more cost.This is certainly contrary to the principle of business which is to get the maximum profit with minimum expenditure.To make efforts to deliver products according to demand with the right route, fast time, and minimum cost, one of the concerns is operational costs.
Operational cost is a definitive cost in every manufacture, both manufacture-based companies and servicebased companies, also as an indicator to determine if a company is operating well or not.Therefore, it needs a location facility to reduce the operational cost as minimum as possible.One of the SMEs in the Rancaekek area -West Java also experienced the problem of distribution costs increases.XYZ SMEs has market share in several cities in Central Java, the distance between production houses and retail shops is quite far resulting in high distribution costs.XYZ need a facility that is able to reduce distribution costs in order to maximize sales profits both in terms of costs and fulfillment of customer needs and satisfaction.In Facilities Planning book which published by John Willey & Sons, Inc., mentioned that facility is a critical component of a graded global network which needed for supply chains superiority.

Literature review
Product distribution from manufacture to customer (Pujawan, 2010): 1. Direct Shipment In this model, the shipment is directly delivered from the manufacture to customer without warehouse or any supporting facilities.This strategy is suitable for goods with low durability and goods that easily to be damaged in loading process.

Warehouse Shipment
In this model, goods aren't delivered directly to customers, but through one or more warehouses or supporting facilities.This model is suitable for products that have uncertain demand or supply, and products that have a relatively strong durability.

Cross Docking
In this model, the pickup and delivery transportation will meet in the cross-dock facility which located between the manufacture and the customers.In this model, the goods are directly transported at different locations so that shippers can be relatively faster and still can achieve good transportation savings due to their existence.this strategy is weak in terms of needs.to determine the ideal location for a certain single distribution point that serve several store or regions.This method calculates the market distance, the amount of shipped goods, and shipment cost.

According to
The step to use the Center of Gravity is explained below: 1. Determine the goods quantity that shipped from the manufacture site to the warehouse site (which will be searched) in each period.
2. Open a map, determine a certain location as the origin point (0,0).3. Place the market location on the coordinate system with origin point as its base.4. Determine the distribution warehouse coordinate by this formula: quantity that shipped to or from point i

Methods
1. Determine the problem formulation from the determination of retail coordinate research.2. Literature study to collecting various theory and literature which help the research process to be the base research.3. Data collecting that this research use is the data collected from a hijab SME at Rancaekek, Bandung.The data contains shipment cost, quantity of the shipped goods, and shipment location.4. Determination of Retail Coordinate found by SME location data and consumer location data processed and plotted by using Google Maps application to obtain the coordinate point from each location.The research method implemented by observation and direct data collecting from XYZ SME. 5. Data processing in this research conducted by using the CoG method based on the theoretical basis.Beside the SME location data and the consumer coordinate point, the authors also using secondary data which are demand data from each customer, and the cost of single goods shipment from manufacture to consumer.The data result will be determined according to variables that needed in this research, which included shipment cost, and customer demand.6. Authors conduct the analysis from data result obtained in a form of comparison between operational cost with or without Distribution Center.7. The research conclusion used to answer the research purpose.

Results and discussions
The research data from XYZ SME are obtained from location and product demand quantity of four retails in Central Java.The distribution activity conducted by one month period in each retail and conducted on different days.
Calculation To obtain the dixWi and diyWi coordinate points, coordinate points (x,y) in each retail multiplied by each retail transportation cost.Therefore, the result obtained are as follows:  4 showed a significant difference of distribution cost.The cost from manufacture site (Bandung) to the retails is IDR 22.711.150.Meanwhile the distribution cost from Distribution Center (Magelang) to the retails is IDR 7.622.900, in which the shipment cost in each retail were reduced significantly.The shipment cost from manufacture site to Distribution Center is IDR 5.089.500,so the total distribution cost that required is IDR 12.712.400.Therefore, XYZ can save the budget for distribution cost for IDR 9.998.750.Based on the distance calculation between manufacture site and Distribution Center to the retails, the distance that need to cover if the distribution conducted from manufacture site is 1446 km.Meanwhile if the distribution process conducted form Distribution Center, it only needs to cover 264,4 km.This result showed the Center of Gravity method affecting the distribution distance.

1 .
The location of Distribution Center which obtained by Center of Gravity calculation were located in coordinate point (-7.51,110.45), which at region of Dusun II, Lencoh, Selo, Boyolali Regency, Central Java.2. Distribution cost difference between manufacture site and distribution center to the retails occurred with IDR 9,998,750 gap. 3. The use of CoG method affecting the distance covered and the transportation cost.From the cost perspective, shipment cost that conducted from manufacture site requires IDR 22,711,150.Meanwhile the shipment cost from Distribution Center only requires 12,712,400.From distance perspective, the distribution distance from manufacture site needs 1446 km to cover.Meanwhile the distribution distance from Distribution Center only needs 264,6 km to cover.

Table 1
Coordinate Point and Each Retail Transportation Cost

Table 2
Center of Gravity CalculationAfter the value of ∑ , ∑ , and ∑  are obtained, input those value into the formula to determine the new Distribution Center coordinate point.The total of distribution cost from Distribution Center to each retail plus shipment cost from manufacture site to distribution center is IDR 12.935.750.Center of Gravity affects the distribution cost and the distribution distance.The table below is the comparison between total distribution distance from manufacture site to retails and total distribution distance from Distribution Center to retails.Based on the CoG calculation, the new coordinate point is located at (-7.51, 110.45).The coordinate point is located on the region of Dusun II, Lencoh, Selo, Boyolali Regency, Central Java 57363 Picture 1 New Distribution Center Location (Left), The Environment of New Distribution Center Location (Right) (Source: Google Maps)The following table is comparison between distribution cost from manufacture site to each retail with Distribution Center to each retail