Introduction

The sustainable supply chain has become a focus for many businesses as a tool to navigate environmental challenges and unforeseen business circumstances. In this regard, having enabling factors can enhance the efficiency of the supply chain. The supply chain includes outsourcing raw materials and components, production and assembly of products, warehousing, order tracking and distribution through various channels, and ultimately delivery to the customer. It also encompasses suppliers, vendors, manufacturers, and retailers that interact through transportation, information, and financial infrastructure, with all activities connected by the flow and transportation of goods from the raw material stage to the final consumer. Management in such a supply chain must operate in a more strategic and comprehensive manner. The domains of the supply chain should encompass all business processes that facilitate speed and accuracy in meeting customer expectations. These processes extend from product development to relationship management. Accordingly, more comprehensive concepts of the supply chain have been proposed by researchers, one of which is sustainable supply chain management, which addresses topics such as the evolutionary nature of the supply chain and management development.

Materials and methods

The present research is applied in nature and falls under descriptive-correlational studies. In terms of data collection and analysis, it employs a descriptive-non-experimental method. This study utilized library research to gather information regarding the supply chain and employed field research through questionnaires. After formulating the research hypotheses, the variables were measured using the questionnaires developed by Vargas, Indurand, and Mantilla (2018) and Cantle and Zardini (2018). In these questionnaires, the enablers of the supply chain were assessed through two components: senior management support (4 questions) and strategic purchasing (8 questions). The social and environmental functions of the supply chain were each measured through 16 questions, while the competitive advantage of the company was evaluated through 6 questions. Additionally, the company’s reputation was assessed through 3 questions. The reliability of the questionnaire was evaluated using Cronbach's alpha coefficient, and the results indicated the reliability of the research tool.This research is cross-sectional in terms of time, and its statistical population consists of the Saipa automotive group. In analyzing the research data, conducted with Smart PLS and SPSS software, descriptive analysis of the research data was first performed. Following that, the normality of the distribution of variables was examined using the Kolmogorov-Smirnov test, and the structural model of the research was evaluated. To assess the validity of the constructs, conventional indices were used, and the results indicated a good fit for the model. Considering the structural equation modeling method in testing the research hypotheses, Klein's (1990) sample size determination method was used to establish the sample size. Since this research includes 6 factors—namely, support from senior and middle managers, strategic purchasing, environmental functions of the supply chain, social functions of the supply chain, company reputation, and competitive advantage—the minimum required sample size according to Klein's recommendation is 120 individuals. However, to ensure the necessary accuracy of the results, a minimum sample size of 200 individuals was considered, and this number was selected using a non-probability convenience sampling method from the target statistical population. Among the sampled managers, 75.5 percent (151 individuals) were male and 24.5 percent (49 individuals) were female. Regarding educational qualifications, there were 47 individuals with a bachelor's degree, 126 with a master's degree, and 27 with a doctoral degree. In terms of managerial experience, 45 individuals had between 10 to 15 years, 84 had between 15 to 20 years, and 71 had more than 20 years of management experience.

Findings

The results of the data analysis indicated that the enablers of the supply chain had a direct and significant impact on the environmental and social functions of the supply chain. Additionally, the environmental and social functions of the supply chain showed a significant effect on the company's reputation and competitive advantage. However, no significant relationship was observed between reputation and competitive advantage; therefore, the influence of the enablers, as well as the social and environmental functions of the supply chain on competitive advantage through the company's reputation, was not confirmed.

Discussion and conclusion

According to the findings of this research, it was observed that improving the level of support from senior and middle managers, as well as implementing strategic purchasing in the company, can lead to an enhancement of the social and environmental functions of the supply chain. Since achieving the company's goals in line with the development and improvement of the supply chain requires having precise plans and the support of managers for the implementation of these plans, the role of senior and middle managers in improving the functions of the supply chain is not unexpected. On the one hand, the company's strategic purchasing, emphasizing planned purchases based on market evaluation and company resources, indicates the targeted nature of the raw material procurement programs. It is expected that strategic purchasing with these characteristics can lead to improved supply chain functions in the company by reducing costs. Therefore, these findings were anticipated. On the other hand, the results indicate a direct impact of supply chain functions on the company's reputation and competitive advantage. However, it should be noted that the automotive industry in Iran is not very competitive, and the monopoly in this industry poses challenges to the concept of competitiveness. This may explain the lack of impact of reputation on competitive advantage in the research model. Nevertheless, the findings suggest that improving supply chain functions can lead to a higher reputation for the company. It is important to note that supply chain functions also encompass the company's distribution and sales channels, and therefore, improvements in these areas are directly perceptible to customers. Thus, an increase in the company's reputation due to enhancements in supply chain functions is not unexpected.Considering that competitiveness in this industry, particularly in Iran, is influenced by the total cost of the product and the profit from product sales, it is expected that improving supply chain functions will increase the company's market share and that production and sales costs will align with pre-established plans. Thus, higher competitiveness for the company can be envisioned through this approach. However, the most significant finding of this research, in the researcher’s view, is the lack of impact of reputation on competitive advantage and, consequently, the rejection of its mediating role in the relationship between supply chain functions and competitive advantage. As previously mentioned, this finding can be attributed to the monopoly in the industry and the different definition of competitiveness within this industry in the country. As long as production monopoly is not held by a few specific companies, it can be expected that with an increase in the company’s reputation, its competitiveness and competitive advantages will also rise. However, when production monopoly is held by one or a few specific companies, competitive advantage loses its significance, and customers are compelled to obtain the desired product solely from these monopolistic companies. Therefore, in such conditions, competitive advantage becomes an unrealistic and irrational concept. Based on this, it seems that supply chain enablers, as long as a production monopoly exists, cannot lead to a more favorable ultimate performance regarding competitive advantage for the company, and this is the most important finding of this research.