Original Research Article: full paper (2022), «EUREKA: Physics and Engineering» Number 6 139 Engineering DECISION MAKING FOR CAR SELECTION IN VIETNAM Do Duc Trung* Faculty of Mechanical Engineering 1 doductrung@haui.edu.vn Dung Hoang Tien Faculty of Mechanical Engineering 1 Nguyen Hoai Son Faculty of Mechanical Engineering 1 1 Hanoi University of Industry 298 Cau Dien str., Bac Tu Liem District, Hanoi, Vietnam, 100000 *Corresponding author Abstract Mid-priced cars (segment B) are attracting the attention of middle-income families in Vietnam. They often consider choos- ing one of three vehicles from three different manufacturers, consisting of Hyundai Accent 1.4AT, Toyota Vios 1.5G, and Honda City 1.5L. This study was carried out to rank those three cars. Twelve criteria for rating each car provided by the dealer were used. These criteria are both qualitative and quantitative, and also fall into all three types, including max, min and another («Yes», «No»). The importance of each criterion was determined by experts in a survey. They are all knowledgeable about cars. Two multi-criteria decision making (MCDM) methods including R (A simple ranking method for multi-attribute decision making in the industrial environment) and CURLI (Collaborative Unbiased Rank List Integration) method were applied for ranking. This is the first work that has used both methods mentioned above. The result revealed that the rank of the alternatives is the same when both the methods were used. This result gives us a certain confidence when choosing a car. Accordingly, Honda City 1.5L is ranked first. R and CURLI not only succeeded in ranking cars in this study, but also promise to be successful when used in other situations. Moreover, other criteria for evaluating the vehicle options that have not been surveyed in this study are mentioned in the last section of this paper. They need to be further considered to include in other next studies for car selection. Keywords: Multi Criteria Decision Making, B-segment car selection, R method, CURLI method. DOI: 10.21303/2461-4262.2022.002505 1. Introduction The demand of purchasing a car for families in Vietnam is remarkably high as the popula- tion size is nearly 100 million people. According to the data of the General Statistics Office (under the Ministry of Industry and Trade of Vietnam), currently, there are 16 cars per 1000 inhabitants in Vietnam [1]. Although the economy was greatly affected by the Covid-19 pandemic, there were more than 400,000 cars registered in 2020 [2], 410,000 cars in 2021 [3], over 51,000 cars in the first four months of 2022 [4]. Thus, it can be said that the need of buying a car is increasing in Vietnam. Among the many types of cars on the market, consumers tend to prefer mid-priced cars (B-segment). There are three types of cars in the B-segment popular in the Vietnamese market, including Hyun- dai Accent 1.4AT, Toyota Vios 1.5G, and Honda City 1.5L. The buyers often choose a certain type of car based on their use habits, the opinions of their friends or their subjective thoughts. Choosing a car also depends on a few criteria such as price, fuel consumption, number of seats in the car, etc. This may lead to inappropriate decisions. Furthermore, there are conflicting selection criteria between the vehicles. For example, the price of the Hyundai Accent 1.4AT is lower than of the Toyota Vios 1.5G, however, the fuel consumption of the Hyundai Accent 1.4AT is higher than of the Toyota Vios 1.5G [5]. This makes it difficult for the customers to choose a car. In fact, there have been cases of conflict between family members in car decision making. This study was conducted to rank the above three types of cars with the aim of being able to give a recommendation to shoppers. The ranking of alternatives by using multiple criteria is also known as multi-criteria deci- sion making (MCDM) [6]. Due to the necessity of multi-criteria decision making in different fields,