Cost Analysis of Distribution of the Covid-19 Vaccineusing K- Means Method and Center of Gravityin Java Island – Indonesia

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

COST ANALYSIS OF DISTRIBUTION OF THE COVID-19 VACCINEUSING K- MEANS METHOD AND CENTER OF GRAVITYIN JAVA ISLAND – INDONESIA

Mira Yanto1, Thyar Romadhon2, Andhika Putrana Isdy3, Fahrul Arifin4, Muchammad Fauzi5 1,2,3,4,5Industrial Engineering Department, Faculty of Engineering, Widyatama University, Bandung, Indonesia 1Corresponding Email: [email protected]

ABSTRACT

The Covid-19 pandemic has caused panic everywhere, hundreds of thousands of people have been infected and thousands of others have died. After vaccines from several countries were found, WHO recommended mass vaccination to prevent Covid-19. The vaccine distribution process has been intensified, including in Indonesia. The vaccine distribution center on the island of Java is located in Bandung City, which is proposed to create a new Distribution Center so that the distribution process of vaccines at the 6 Health Offices in Java Island can be carried out quickly, in a structured manner, and that the distribution costs incurred are a minimum. The research objective was to analyze transportation costs by designing a distribution network of several distribution schemes to minimize the distribution costs for the covid-19 vaccine in Java using the K-means Method and the Center of Gravity Method. The results of the research to determine the clusterization obtained 2 clusters. Cluster 1 consists of the provinces of Central Java, D.I Yogyakarta, and East Java, cluster 2 consists of the provinces of DKI Jakarta, Banten, and West Java. From the 2 clusters, we determined the location of the new Distribution Center and obtained 2 Distribution Centers. DC cluster 1 is located at (-7.318609331, 111.3109342) Gembol area, Karanganyar District, Ngawi Regency, East Java, and DC cluster 2 is located at (-6.394390567, 106.8367357) JL Area. Sentosa Raya 9-16, Mekar Jaya, Sukmajaya District, Depok City, West Java. The total transportation cost for distributing the Covid-19 vaccine in scheme 1 is Rp. 67.748.880, the proposal for scheme 2 is Rp. 92.391.067, and the proposed scheme 3 is Rp. 80.089.714.

Keywords:Vaccine, Covid-19, Distribution, K-Means Method, Center of Gravity

I. INTRODUCTION The corona virus (Covid-19) pandemic has raised new challenges that must be overcome immediately by a country. Many countries carry out policies that are implemented in every part of their territories such as a lockdown policy system, or policies to maintain distance from the community (Valerisha & Putra, 2020). Other efforts that can be made by the community are by properly understanding the symptoms of covid-19 and the community must implement clean and healthy living behavior, namely by maintaining cleanliness and physical fitness, frequently washing hands with soap or antiseptic liquid, wearing masks, applying ethics. Coughing and sneezing properly, maintaining distance, and limiting activities outside the home if there is no need (Humairo, et al., 2021). Some countries show the success of this policy, but some show the failure of this policy. Thus, to break the chain the spread of the covid-19 virus is to implement health protocols and carry out vaccination efforts (Valerisha & Putra, 2020).

After the discovery of vaccines by several countries in the world, the World Health Organization (WHO) recommended that all countries carry out mass vaccinations to prevent covid-19 (Rahman, 2021). Covid-19 vaccination aims to reduce the transmission of covid-19, reduce the death rate from covid-19, and protect the public from covid-19 (Ministry of Health, 2021). Government policy in responding quickly to the development of vaccine research and the use of vaccines as a solution in overcoming pandemic problems in Indonesia (Shafa & Sriwidodo, 2021).

www.turkjphysiotherrehabil.org 9731

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

The pandemic problem in Indonesia has finally been formally resolved through Presidential Decree 99 of 2020 and Minister of Health Regulation Number 84 of 2020 concerning Implementation of Vaccinations in the Context of Covid-19 Pandemic Management (Farmalkes, 2021). The Presidential Regulation on Vaccines mostly regulates cooperation in vaccine distribution and also has several roles in implementing vaccine distribution in Indonesia. The implementation of vaccination in Indonesia is carried out simultaneously by 34 Provinces in stages. In January, the focus of vaccination is on the provincial capitals and districts/cities bordering the capital city. It is targeted that in February, all targets for Health Human Resources will have been vaccinated (Ministry of Health, 2021).

Indonesia has a land area of 1.92 million square kilometers with a population density of 14 people per square kilometer. According to Central Statistics Agency(2021), the results of the Population Census (SP2020) in September 2020 recorded a population of 270.20 million people. The distribution of Indonesia's population is still concentrated on the island of Java. Although the geographical area is only about 7% of the entire territory of Indonesia, the population of Java Island is 151.59 million people. The male population is more than female, namely 76.3 million and 75.20 million, respectively. The province in Java which has the largest population in West Java, reaching 48.27 million people. Then followed by East Java with 40.66 million people, then Central Java with 36.51 million people. Then, Banten with a population of 11.91 million, DKI Jakarta 10.56 million, and the Special Region of Yogyakarta 3.66 million as illustrated in Figure 1.

Banten East Java DI Yogyakarta Central Java West Java DKI Jakarta

0 5000000 10000000 15000000 20000000 25000000

DI DKI Jakarta West Java Central Java East Java Banten Yogyakarta Female 5227307 23765277 18153892 1850792 20374104 5834291 Male 5334781 24508885 18362143 1817927 20291592 6070271

Female Male

Figure 1. Graph of the population in Java 2020 The density of the population on the island of Java will greatly impact the spread of the covid-19 virus. To prevent infection with the covid-19 virus, the Government provides vaccines to all Indonesians for free. In Indonesia, the vaccine company and given the responsibility by the government for the distribution of the covid- 19 vaccine is PT. XYZ. PT. XYZ is located in Bandung, West Java, which is engaged in the pharmaceutical industry specifically for vaccines in Indonesia, for the covid-19 vaccine is a special treatment so that its distribution is directly sent to the Provincial Health Office throughout Indonesia. The next process is the distribution process from the provincial level to the district or city level using vehicles equipped with special refrigeration facilities, cold boxes, vaccine carriers or other means of transportation for vaccines that are compatible with the type of covid-19 vaccine. For other supporting equipment and logistics using other standard carriers by the provisions (Topan & Yuniarto, 2021).

The distribution of logistical assistance is a system of distributing and/or distributing logistical assistance from the area of origin to the destination area at the intended target (National Disaster Management Agency, 2019). Based on Presidential Decree No.7 of 2020, covid-19 disaster management forms a distribution network of logistical assistance designed based on Presidential Decree No.7 of 2020 which states that the distribution of logistical assistance starts from the central, provincial, district/city levels to warehouses according to its objectives and based on the channel approach. A selective distribution eliminates unprofitable distributors on the distribution network (Fauzi & Oktarina, 2020).

According to Sadiqin as Division Head of Marketing at PT. XYZ assessed that the transportation costs for distributing Covid -19 vaccine products at PT. XYZ is very high because the distance of each destination is far www.turkjphysiotherrehabil.org 9732

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

and different, coupled with large variable costs and fixed costs, the transportation costs for distributing the covid- 19 vaccine are very expensive. Based on these problems, the purpose of this study is to analyze the right distribution network to produce an optimal total distribution cost in Java using the K-means and Center of Gravity methods, then to calculate the distribution costs incurred in vaccine delivery it is calculated based on the vehicle operating costs.

II. LITERATURE REVIEW Distribution is the process of distributing goods or services to be used or consumed by consumers (Ratnasari, Yuniarti, & Purnamasari, 2020). In distribution, of course, it cannot be separated from distribution costs. Factors affecting distribution costs at PT. XYZ, among others, distribution distance and vehicle capacity. One of the determinations of distribution costs depends on the distance traveled, so it is necessary to cluster in order to find a distribution center that is suitable for each cluster. The K-means method is used by researchers to determine the right cluster based on the closest distance to create a distribution center that is close to the destination, so that the distribution process is optimal.

In this study, the K-means method is used to determine clusters based on the closest distance. The distribution locations to be clustered consist of 6 provinces on the island of Java. K-Means Cluster Analysis is a non- hierarchical cluster analysis method that enters objects or data into one or more clusters that have been determined based on their characteristics (Puntoriz & Fibriani, 2020). The clusters that we get from the calculation are 2 clusters, which will be continued to determine the Distribution Center point using the Center of Gravity.

n 2 dij = k=1(xik xjk ) (1)

∑ − The Center of Gravity or Gravity Location �Models method is one method that can be used to determine the location of facilities (for example, warehouses or factories) that connect sources of supply and several market locations (Anshori, Fudhla, & Hidayat, 2017). In this study, it is divided into 2 clusters, namely the western region and the eastern region, each of which is calculated at the Center of Gravity to determine the New Distribution Center. The new Distribution Center is used to find out whether distribution through the new Distribution Center results in a more optimal total cost or not than a direct distribution from the center, namely PT. XYZ After obtaining the results of the clustering, then determining the location of the distribution center using the Center of Gravity approach (Fauzi & Oktarina, 2020).

= = 𝐤𝐤 𝐃𝐃𝐧𝐧𝐅𝐅𝐧𝐧𝐱𝐱𝐧𝐧 (2) ∑𝐧𝐧 𝟏𝟏 𝐝𝐝 ′ = 𝐧𝐧 𝐤𝐤 𝐃𝐃𝐧𝐧𝐅𝐅𝐧𝐧 𝐱𝐱 ∑𝐧𝐧 𝟏𝟏 𝐝𝐝𝐧𝐧 = = 𝐤𝐤 𝐃𝐃𝐧𝐧𝐅𝐅𝐧𝐧𝐲𝐲𝐧𝐧 (3) ∑𝐧𝐧 𝟏𝟏 𝐝𝐝 ′ = 𝐧𝐧 𝐤𝐤 𝐃𝐃𝐧𝐧𝐅𝐅𝐧𝐧 𝐲𝐲 ∑𝐧𝐧 𝟏𝟏 𝐝𝐝𝐧𝐧 The next step is to calculate the cost of distribution costs to each health office of the province of destination.

n Min TC = t=1 Vi x Ri x di

In calculating the transportation costs incurred in vaccine∑ delivery, vehicle operating costs are required (Hasanah et al., 2020). The determination of vehicle operating costs is determined in 2 types, namely fixed vehicle operating costs and non-fixed vehicle operating costs. Determination of vehicle operating costs obtained per year at PT XYZ is converted into costs per month.

Actual Distance OT = BOK + BOK + x Fuel Price (/L) (Not Fixed /Month ) (Fixed /Month ) Fuel Consumption (/km ) (5) �� III. METHODOLOGY This research was conducted consisting of several stages, starting from the identification of the problem and research objectives, literature review, data collection, data processing (method), analysis, conclusions and suggestions as depicted in Figure 2.

www.turkjphysiotherrehabil.org 9733

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

Start

Identification Problems and Research Purpose

Literature Review

Data Collecting

Data Processing Determination of the K-Means Method Number of Clusters Determination of Center Of Gravity Distribution Center Method Warehouses per Cluster

Total Cost Determining the Scheme Calculation of to be Used for the Vaccine Each Scheme Distribution Process

Analisys

Conclusions and Suggestions

End

Figure 2. Research Flow Researchers identify problems to be raised based on the objectives of the research at PT. XYZ. Then the researchers conducted a study in accordance with the topic to solve the distribution cost problem. This study focuses on comparing the distribution costs of vaccines on the island of Java from several schemes obtained in order to obtain the minimum total cost. After that the researcher collected relevant information from other research materials as a reference to be used as a research method. Some of the methods we use in this study are Vehicle Operating Costs, K-means Method and Center Of Gravity. The data we use in this study come from primary and secondary data. Primary data obtained from direct retrieval at PT. XYZ is in the form of demand data, the number of provincial level health offices on the island of Java, the location of the provincial level health offices on the island of Java, the distance to each point, the number of packs in a koli and the capacity of the trucks to carry them. Secondary data were obtained from other studies related to the analysis under study. In data processing, the first step is grouping the clusters based on the closest distance using the K-means algorithm method. Then look for a new distribution center point in each cluster. After that, a comparative analysis of the total distribution costs of several schemes will be carried out by researchers to analyze by collecting monthly demand data and location maps in each province to determine the distance and location points of each province. Scheme 1: Total fees from PT. XYZ Go directly to the 6th Provincial Health Office on the island of Java, Scheme 2: Total costs from PT. XYZ through the Distribution Center 1 to the cluster 1 provincial health office on the island of Java and the Distribution Center 2 to the cluster 2 provincial health office on the island of Java and Scheme 3: Total costs from PT. XYZ to the Provincial Health Office of DKI Jakarta, Banten, West Java and Distribution Center 1 to the Provincial Health Office of D.I Yogyakarta, East Java, and Central Java.

IV. RESULTS AND DISCUSSION Results and data analysis obtained based on the distribution network of the covid-19 vaccine PT. XYZ on the island of Java, which is a distance from the Distribution Center of PT. XYZ goes to the DKI Jakarta Provincial Health Office for 152 km, the Banten Provincial Health Office for 232 km, the West Java Provincial Health Office for 0.2 km, the Central Java Provincial Health Office for 436 km, the Provincial Health Office for D.I. Yogyakarta is 561 km, and the East Java Provincial Health Office is 772 km, as illustrated in Figure 3. The distribution network for product delivery is carried out from the factory directly without a Distribution Center, so there is a need for analysis before and after using a Distribution Center.

www.turkjphysiotherrehabil.org 9734

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

152 KM DKI Jakarta Departement of Public Health

232 KM Banten Departement of Public Health

Distribution Center 0.2 KM PT. XYZ West Java Departement of Public Health

436 KM Central Java Departement of Public Health

561 KM D.I Yogyakarta Departement of Public Health

772 KM East Java Departement of Public Health

Figure 3. Vaccine distribution network of covid-19 at PT XYZ Middle Java Determination of clustering in Java, it was found that there were 6 provinces to be researched by looking at Figure 3 with different distances, so to calculate the Total Cost and the closest distance to distribute goods more quickly and easily, a clustering calculation was made using the K-Means method and then searched. Distance with decimal degrees using Google. Maps from the distribution source PT. XYZ to each destination provincial Health Office as shown in table 1.The request for each province is different, namely where the number of deliveries is made every month, namely for DKI Jakarta as much as 228.080/month, Banten 96.280/month, West Java as much as 353.120/month, Central Java 371.720/month, DI Yogyakarta 75.600/month, East Java 311.160/month. Meanwhile, shipments are calculated per container, where each box contains 1960 doses/vial of covid-19 vaccine, so the need for trucks will affect the number of koli sent with a shipping capacity of 33 containers per truck. The results of clustering based on distance using the K-means method can be seen in Table 2 and Table 3.

Table1.Data Collection Delivery Decimal Degrees Province Volume Distance From the Factory (km) X Y (Month) DKI Jakarta 228080 -6.163770 106.816294 152 Banten 96280 -6.163451 106.151377 232 West Java 353120 -6.898776 107.599723 0,2 Central Java 371720 -6.982532 110.421823 436 D.I Yogyakarta 75600 -7.782755 110.362514 561 East Java 311160 -7.279164 112.763641 772

Table 2. An early iteration of clusterization Province C1 C2 The Closest Distance Cluster DKI Jakarta 0 0,664917424 0 C1 Banten 0,664917424 0 0 C2 West Java 1,074241542 1,624318713 1,074241542 C1 Central Java 3,697325165 4,348288136 3,697325165 C1 D.I Yogyakarta 3,898305703 4,511742801 3,898305703 C1 East Java 6,051036045 6,705732846 6,051036045 C1

Table 3.The final iteration Province C1 C2 The Closest Distance Cluster DKI Jakarta 4,524146659 0,248061117 0,248061117 C2 Banten 5,168879855 0,745881882 0,745881882 C2 www.turkjphysiotherrehabil.org 9735

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

West Java 3,611006419 0,89086083 0,89086083 C2 Central Java 0,844125641 3,611905282 0,844125641 C1 D.I Yogyakarta 0,928180809 3,766321536 0,928180809 C1 East Java 1,582485782 5,971630721 1,582485782 C1

Based on the clustering of 6 provinces in the island of Java, namely the provinces of DKI Jakarta, Banten, West Java, Central Java, D.I Yogyakarta, and East Java, it produces 3 iterations. With the K-means method approach, 2 clusters are obtained. Cluster 2 consists of DKI Jakarta, Banten, West Java and cluster 1 consists of Central Java, D.I Yogyakarta, and East Java.

The next step is to determine the location of the Covid-19 Vaccine Distribution Center. Determination of the location of the Distribution Center is determined based on the results of distance, koli volume, and decimal degrees, where previously clustered calculations were carried out to obtain new points X and Y for Cluster 1 and Cluster 2 as shown in table 4 and table 5. The new points will become the location of the starting point of PT. XYZ to the destination of each Distribution Center can be seen in table 6.

Table 4. Processing of location coordinates of new Distribution Center 2

Decimal Degrees Volume Transportation Volume x OT Vo lu me x OT x Xi Vo lu me x OT x Yi (Koli/Month) Cost (Koli) X Y -6.163770449 106.816294 117 Rp 85,298 Rp 9,979,867 -Rp 61,513,607 Rp 1,066,012,372

-6.163451027 106.1513767 50 Rp 195,085 Rp 9,754,267 -Rp 60,119,945 Rp 1,035,428,835 -6.898776023 107.5997235 181 Rp 49,885 Rp 9,029,213 -Rp 62,290,520 Rp 971,540,858 TOTAL Rp 28,763,347 -Rp 183,924,073 Rp 3,072,982,066

Table 5. processing location point of new Distribution Center 1

Decimal Degrees Volume Transportation Volume x OT Vo lu me x OT x Xi Vo lu me x OT x Yi (Koli/Month) Cost (Koli) x y -6.98253236 110.4218235 190 Rp 69,083 Rp 13,125,733 -Rp 91,650,858 Rp 1,449,367,409 -7.78275518 110.362514 39 Rp 276,542 Rp 10,785,133 -Rp 83,938,052 Rp 1,190,274,428 -7.27916447 112.7636408 159 Rp 94,809 Rp 15,074,667 -Rp 109,730,978 Rp 1,699,874,297 TOTAL Rp 38,985,533 -Rp 285,319,888 Rp 4,339,516,134

Table 6. The Point Location of New Distribution Center

Decimal Degrees Cluster Distance X' Y' Location JL. Sentosa Raya 9-16, Mekar Jaya, Kec. DC 2 157 KM -6.39439056 106.8367357 Sukmajaya, Kota Depok, Jawa Barat. Gembol, Kec. Karanganyar, Kabupaten Ngawi, DC 1 621 KM -7.31860933 111.3109342 Jawa Timur

The design of the distribution network of the Covid-19 vaccine is based on the results of clustering calculations in table 2 and table 3, so that a new distribution center for cluster 1 and cluster 2 is obtained in table 6, so the results can be shown in Figure 4.

www.turkjphysiotherrehabil.org 9736

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

Figure 4. Distribution Network Proposal of Vaccine Covid-19 in Middle Java

Analysis obtained from data collection and processing that has been done. The data collected is then processed using clustering based on distances and decimal degrees X and Y, the comparison of the calculation results of transportation costs from the 3 schemes. Scheme 1 total costs from PT. XYZ directly to 6 provincial health offices on the island of Java, scheme 2 total costs from PT. XYZ through Distribution Center 1 to the cluster provincial health office on the island of Java and distribution center 2 to cluster 2 provincial health office on the island Java. Scheme 3 costs the total cost of PT. XYZ to the provincial health office in Jakarta, Banten, and distributor center 1 to the provincial health office of DI Yogyakarta, East Java and Central Java. The result of these calculations are different for each province, this is because the number of different demand volumes and different distances effects changes in distance and transportation costs so that the distribution costs of the Covid- 19 vaccine before there is a distribution center and after there is a distribution center will be different. Table 7 shows the results of calculating the transportation costs of each province and the total transportation costs of each province and the total transportation costs by direct means without using clusters and Distribution Centers.

Table 7. Calculation results of Total Transportation Cost Scheme 1 I (Department of Public Health) V (Koli/Month) R (Cost/Koli) OT DKI Jakarta 117 Rp85.298 Rp9.979.867 Banten 50 Rp195.085 Rp9.754.267 West Java 181 Rp49.885 Rp9.029.213 Central Java 190 Rp69.083 Rp13.125.733 D.I Yogyakarta 39 Rp276.542 Rp10.785.133 East Java 159 Rp94.809 Rp15.074.667 Total Rp67.748.880 Table 8 shows the total distribution costs that apply the results of the k-means method and center of gravity, namely distribution center 1 and distribution center 2. Distribution Center 1 to the cluster 1 provincial health office which includes the provinces of Central Java, DI Yogyakarta, and East Java and Distribution Center 2 to the cluster 2 provincial health office covering the provinces of DKI Jakarta, Banten, and West Java.

Table 8. Calculation results of Total Transportation Cost Scheme 2 I V R OT I V R OT DC 2 348 Rp33.715 Rp11.732.967 DC 1 388 Rp53.356 Rp20.702.133 DKI Jakar 117 Rp85.566 Rp10.011.200 Central Java 190 Rp55.181 Rp10.484.333 ta D.I Banten 50 Rp183.116 Rp9.155.800 Yogyak 39 Rp245.369 Rp9.569.400 arta West Java 181 Rp56.159 Rp10.164.733 East Java 159 Rp66.481 Rp10.570.500 Total Rp41.064.700 Total Rp51.326.367 Table 9 and Table 10 show the total cost of distributing the Covid-19 vaccine at PT. XYZ where cluster 2 is without a new distribution center but for cluster 1 it is through Distribution Center 1.

Table 9.Calculation results of Total Transportation Cost Scheme 3 cluster 2 without DC www.turkjphysiotherrehabil.org 9737

Turkish Journal of Physiotherapy and Rehabilitation; 32(3) ISSN 2651-4451 | e-ISSN 2651-446X

I(Department of Public Health) V (Koli/ Month) R (Cost/Koli) OT DKI Jakarta 117 Rp. 85.298 Rp. 9.979.867 Banten 50 Rp. 195.083 Rp. 9.754.267 West Java 181 Rp. 49.885 Rp. 9.029.213 Total Rp. 28.763.347 Table 10.Calculation results of Total Transportation Cost Scheme 1with DC

I(Department of Public Health) V(Koli/ Month) R (Cost/Koli) OT DC 1 388 Rp53.356 Rp20.702.133 Central Java 190 Rp55.181 Rp10.484.333 D.I Yogyakarta 39 Rp245.369 Rp9.569.400 East Java 159 Rp66.481 Rp10.570.500 Total Rp51.326.367

V. CONCLUSION Based on the results of the discussion and analysis, it is concluded that to design a distribution network for Covid-19 vaccine products in Java, the following results are obtained:

1. Scheme 1: Total distribution costs from PT. XYZ directly to the Provincial Health Office of DKI Jakarta, Banten, West Java, D.I Yogyakarta, East Java and Central Java obtained Rp. 67.748.880. 2. Scheme 2: Total distribution costs from PT. XYZ through the Distribution Center 1 to the Provincial Health Office of D.I Yogyakarta, East Java and Central Java as well as from PT. XYZ through the Distribution Center 2 to the Provincial Health Office of DKI Jakarta, Banten, West Java, obtained Rp. 92.391.067. 3. Scheme 3: Total distribution costs from PT. XYZ went directly to the Provincial Health Office of DKI Jakarta, Banten, and West Java and from PT. XYZ through the Distribution Center 1 to the Provincial Health Office of D.I Yogyakarta, East Java and Central Java, obtained Rp. 80.089.714. Based on the total distribution costs above, the proposed scheme 2 and scheme 3 have a higher total distribution cost than scheme 1 without a distribution center point. Thus, the existence of regional clustering and distribution center location points for the distribution of covid-19 vaccine products is not effective and is not recommended because it has an increase in distribution transportation costs of Rp. 24.642.187 for scheme 2, and the difference in increase is Rp. 12.340.834 for scheme 3.

REFERENCES 1. Anshori, M., Fudhla, A. F., & Hidayat, A. (2017). Penentuan Lokasi Fasilitas Crossdock pada Kota Metropolis dengan Pendekatan Center Of Gravity. Teknika: Engineering and Sains Journal, 1(2), 83-88. 2. Badan Nasional Penanggulangan Bencana. (2019). Perka 18 Tahun 2010 tentang Pedoman Distribusi Bantuan Logistik dan Peralatan Penanggulangan Bencana. https://bnpb.go.id/berita/perka-18-tahun-2010-tentang-pedoman-distribusi-bantuan-logistik-dan-peralatan- penanggulangan-bencana. 3. Badan Pusat Statistik. (2021). Berita Resmi Statistik. https://www.bps.go.id/pressrelease/2021/01/21/1854/hasil-sensus-penduduk-2020.html. 4. Farmalkes. (2021). Peraturan Menteri Kesehatan.https://farmalkes.kemkes.go.id/: https://farmalkes.kemkes.go.id/peraturan/permenkes/. 5. Fauzi, M., & Oktarina, R. (2020). Usulan Perancangan Jaringan Distribusi dan Penentuan Titik Lokasi Pusat Distribusi Bantuan Logistik Medis Covid-19 Di Jawa Barat. Jurnal Rekayasa Sistem Dan Industri, 7. 6. Hasanah, T. U., Utami, P., & Fauzi, M. (2020). Pengoptimalan Biaya Transportasi dengan Metoda North West Corner (NWC) dan Stepping Stone (SS) untuk Distribusi Produk Farmasi. Jurnal Teknik Industri: Jurnal Hasil Penelitian dan Karya Ilmiah, 6, 34-39. 7. Humairo, A., Pratiwi, A. Y., Hasanah, S. M., Fitroh, W. F., Lia, I., & Irnawat, J. (2021). Upaya Pencegahan Pemutusan Mata Rantai Penularan Virus Corona di Yayasan Pondok Pesantren Al-Hanif Kota Tangerang Selatan. Jurnal Pengabdian Kepada Masyarakat (PKM): Kreasi Mahasiswa Manajemen, 1(1), 28-32. 8. Kementerian Kesehatan. (2021, January 7). SK Dirjen Nomor HK.02.02/4/1/2021 Tentang Petunjuk Teknis Pelaksanaan Vaksinasi dalam Rangka Penanggulangan Pandemi Covid-19. https://promkes.kemkes.go.id/sk-dirjen-nomor-hk0202412021-tentang-petunjuk-teknis-pelaksanaan-vaksinasi- dalam-rangka-penanggulangan-pandemi-covid19. 9. Puntoriz, & Fibriani, C. (2020). Analisis Persebaran UMKM Kota Malang Menggunakan Cluster K-means. Journal of Information System, 5, 86-94. 10. Rahman, Y. A. (2021). Vaksinasi Massal Covid-19 sebagai Sebuah Upaya Masyarakat dalam Melaksanakan Kepatuhan Hukum (Obedience Law). Khazanah Hukum, 3, 80-86. 11. Ratnasari, Y., Yuniarti, D., & Purnamasari, I. (2020). Optimasi Pendistribusian Barang Dengan Menggunakan Vogel’s Approximation Method dan Stepping Stone Method. Jurnal Eksponensial, 10(2), 165-174. 12. Shafa, A., & Sriwidodo. (2021). Microneedle: Teknologi Baru Penghantar Vaksin COVID-19. Majalah Farmasetika, 6(1), 85-98. 13. Topan Yuniarto. (2021, January 22). Program Vaksinasi Covid19 Tahapan Distribusi dan Efikasi. https://kompaspedia.kompas.id/baca/paparan- topik/program-vaksinasi-covid-19-tahapan-distribusi-dan-efikasi. 14. Valerisha, A., & Putra, M. A. (2020). Pandemi Global COVID-19 dan Problematika Negara-Bangsa: Transparansi Data Sebagai Vaksin Socio- digital? Jurnal Ilmiah Hubungan Internasional, 131-137.