## 1 Introduction
For the case study, the remanufacturing of CV joints in Korea has been considered to evaluate the economic and environmental impacts during the end-of-life operations of a CV joint. Most previous research focuses only on either environmental assessment or economic impact, such as market size or the amount of subsidy [10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22]. However, the objective of this study is to consider both economic and environmental impacts and to find a relationship between the two. Actual vehicle sales data are used to estimate the demand for CV joint replacements each year, which is the most important part of this study. The estimated demand, using the proposed replacement framework with assumptions, can be used to evaluate the environmental impact and economic impact (total profit) as the portion of remanufactured CV joints increases and to suggest the amount of subsidy. Remanufactured products are assumed to be priced lower compared to new ones, meaning that increasing the production of remanufactured products potentially reduces profits for automakers or suppliers while reducing environmental impact. The calculated demand for CV joint replacements using the proposed framework is used for sensitivity analysis on environmental impact and total profit change according to the increased portion of remanufactured CV joints in the case of replacement. The relationship between economic and environmental impacts as remanufactured CV joints increase has been identified through sensitivity analysis based on different situations, such as preferences or profits on remanufactured CV joints. This relationship can be used as a guide for policymakers to decide how much subsidy should be provided to the remanufacturing industry. A number of studies have focused on the remanufacturing of automotive parts as more countries are forced to consider the environmental aspects of automotive parts for sustainable design [5; 6; 13; 15; 18; 23]. The USA and several European countries have been preparing for the remanufacturing industry for sustainable vehicle design by enacting lawsand regulations. [PERSON] and [PERSON] studied how the End-of-Life Vehicles Directive affects the remanufacturing industry and how such legislation impacts the environmental footprint of the vehicle industry from the European perspective [13]. In Korea, the remanufacturing industry is in the early stages as the policy \"The Act for Recycling of Electrical and Electronic Equipment and Automobiles\" has been in effect since 2008. Recently, there has been increasing interest in the remanufacturing industry in Korea. Many researchers in Korea have studied the status of automotive part remanufacturing and strategies for the domestic market to adopt remanufacturing [2; 3; 4; 5; 6]. Furthermore, remanufacturing technologies of automotive parts are being studied to extend the life expectancy of vehicles [2]. Manufacturing automotive parts requires significant energy consumption and raw materials, leading to high levels of CO2 emissions. Therefore, it is necessary to estimate how many automotive parts are environmentally related during the manufacturing or disposal process [15; 17; 23]. [PERSON] and [PERSON] conducted a life cycle assessment model for automotive parts [10]. [PERSON] also evaluated the life cycle assessment of lightweight vehicles based on end-of-life scenarios but did not consider any economic assessment of automotive parts [18]. [PERSON] and [PERSON] evaluated both environmental and economic assessments under the situation of recycling automotive parts. Remanufacturing automotive parts should involve both aspects as they are closely connected. Some studies have considered both the economic and environmental aspects of automotive parts remanufacturing. [PERSON] et al. studied the economic and environmental assessment of the alternator automotive part [12]. They concluded that the market price of a remanufactured component is incorrect and that remanufacturing significantly reduces the environmental burden compared to new production.