1. Introduction

Supply chain management is a process that spans the entire supply chain and aims to optimize processes and resource allocation at all stages to meet customer needs, improve efficiency and reduce costs. Supply Chain Management (SCM) has long been one of management science's most productive research areas [1]. Sustainable supply chain management is a new concept that has been gradually introduced in the field of supply chain management in recent years, which emphasizes the principle of "triple bottom line" (proposed by Elkington in 1994) that enterprises should consider the economic, environmental and social sustainability in their operations. Traditional supply chain management focuses more on economic benefits but ignores environmental and social impacts, making it challenging to achieve long-term sustainable development. Sustainable supply chain management can not only meet social and environmental requirements but also enhance the competitiveness and brand value of enterprises.

At present, the sustainable development of supply chains has become an essential issue in the field of corporate social responsibility. The notion of a sustainable supply chain encompasses not only financial considerations but also wider social and environmental issues. In essence, sustainability revolves around mitigating the adverse human, social, and environmental effects of business operations while simultaneously delivering value to customers, business partners, and stakeholders [2]. Many companies, including Apple Inc, have realized the importance of sustainable supply chain management and are actively exploring ways to improve their supply chains. This study aims to fill this research gap by examining the critical success factors of sustainable supply chain management using Apple as a case study.

The subject of this paper is to assess the key factors that contribute to the success of the sustainability of Apple's supply chain, using the company as an example.

The specific research questions are as follows

a. The current state of Apple's supply chain sustainability;

b. What are the problems and challenges in the sustainability of Apple's supply chain? How can they be addressed;

c. What are the critical success factors of Apple's sustainable supply chain management?

This paper uses a research methodology of literature analysis and case studies to analyze Apple's successes and challenges in supply chain sustainability.

The significance of this thesis is that it explores the critical success factors of Apple's supply chain sustainability, with implications for other companies to improve their performance and competitiveness in sustainability.

Secondly, this study informs the academic community in the supply chain sustainability research field by filling a research gap in the field of sustainable supply chain management, particularly in the context of one particular company.

2. The Current State of Apple's Supply Chain Sustainability

As the economy and technology continue to evolve, environmental issues and social responsibility are becoming increasingly thought-provoking. Driven by internal and external factors, all industries are recognizing the urgency and importance of improving sustainable supply chain management. By enriching sustainability strategies, improving supply chain management systems, and combining the two, thereby eliminating supply chain waste and making supply chains more profitable [3].

Apple opened up about environmental and social responsibility in its supply chain in its 2014 Annual Supply Chain Responsibility Report and committed to taking action to improve these issues. Since then, Apple has been working continuously to achieve its supply chain sustainability goals.

2.1. Environment

Linking environmental sustainability to company performance as more and more companies consider implementing sustainability internally and in coordination with other companies in their supply chain [4]. Apple is committed to reducing the environmental impact of its supply chain. To achieve this goal, the company has taken a variety of steps, and since 2018, Apple has been using 100 per cent renewable energy to power its global corporate operations and working with its global supply chain to promote clean energy worldwide. Throughout the entire lifecycle of a product, starting from the procurement of materials to the ultimate recycling of the product and its components, Apple collaborates with its worldwide suppliers and partners to ensure the continuous fulfilment of its sustainability and efficiency objectives.

"Apple calls on the global supply chain to decarbonize by 2030," published by Apple Newsroom.

2.2. Social Responsibility

Generally speaking, a company's primary motivation is to maximize its profits [5]; however, driven by external factors such as worker safety hazards, child labor issues, human rights issues, and corporate social ethics, corporate social responsibility has become particularly important. Companies need to increase their ethical responsibility to consider not only profits but also to act in the interests of society and meet its needs [6].

Apple's corporate social responsibility objectives are focused on the three P's – people, planet, and progress [7]. Apple puts its employees, associates, and customers at the heart of everything it does. Back in 2015, Apple established a Supplier Code of Conduct and said it would work closely with suppliers to ensure compliance. With an unwavering commitment to a robust Supplier Code of Conduct, the company upholds the most stringent principles, ensuring the safeguarding of the environment and preserving the well-being of all individuals involved in the supply chain. This includes upholding workers' rights and mandating suppliers to establish comprehensive training initiatives for factory managers and workers alike. Since 2008, Apple has provided education and development programs for supplier employees to help them develop better professionally and personally. The incidence of excessive overtime is reduced by tracking the hours worked by factory employees. Second, Apple has a zero-tolerance policy for child labor, working to eliminate child labor in the industry and ensuring that victims of child labor return to school and are compensated [8]. Also, Apple has established a supplier audit mechanism through third-party oversight to build its credibility in terms of corporate social responsibility. Apple's suppliers publish an annual Supplier Responsibility Report to showcase the corporate social responsibility initiatives undertaken by Apple.

2.3. Supply Chain Structure

Apple's supply chain structure is made up of hundreds of direct and indirect suppliers. Apple places a strong focus on sustainability and social responsibility in the selection and management of its suppliers. Its supplier evaluation system includes rigorous audit criteria and processes to ensure that all suppliers comply with environmental and labor regulations and are committed to reducing environmental pollution and human rights issues. Apple is also actively involved in the training and upgrading of suppliers to help them improve their productivity and sustainability performance. In addition, Apple promotes a sustainable supply chain by establishing long-term strategic partnerships with suppliers. These initiatives reflect Apple's sustainability philosophy and practices in supplier selection and management. Apple uses an 'integrated' model to control the entire supply chain process and requires its suppliers to comply with a range of environmental and social responsibility standards. Apple has increased transparency in its supply chain, raising its visibility by making supplier lists and audit reports publicly available for monitoring and management. In 2019, Apple worked closely with partners to conduct 1,142 supplier assessments in 49 countries around the world, demonstrating Apple's commitment to the proper implementation of all its policies [9].

Overall, Apple's excellence in supply chain sustainability has become a role model for the industry, providing a reference for many companies in the industry.

3. The Problems and Challenges in the Sustainability of Apple's Supply Chain

3.1. Problems and Challenges

Apple does not manufacture its products directly but has hundreds of suppliers around the world who provide raw materials, components, and assembly services. As a result, the management of its many suppliers is an important issue for Apple, although the company has established a Supplier Code of Conduct, which requires suppliers to comply with environmental regulations, labor rights, business ethics, and other standards, as well as promoting sustainable production and operational models [10]. However, with a large number of suppliers located in many countries and regions with different systems, cultures, and stages of development, Apple needs to find a balance between the differences.

Apple's supply chain involves a large number of labor and human rights issues, such as working conditions, wages, salaries, working hours, etc. Sustainability issues such as environmental protection, human rights, and occupational health are gaining increasing attention. Apple must continue to enrich its management content and expand the management points of supplier responsibility practices to meet the sustainable development needs of regulators, investors, consumers, and the public. In the case of Foxconn in China, child labor and suicides reflect that corporate social responsibility policies are not universally implemented. Apple has been accused of not adequately monitoring and ensuring that its suppliers comply with its social responsibility standards, leading to non-compliance. These incidents served as a cautionary tale for Apple to improve the sustainability of its supply chain, prompting it to strengthen regulation, increase transparency and adopt more stringent auditing and assessment measures to ensure that labor rights in the supply chain are fully respected and protected. This experience also serves as a reminder to other companies to focus on social responsibility in supply chain management and to ensure that every link in the supply chain is in line with sustainability principles.

Apple's supply chain involves significant resource and energy consumption. According to Apple's 2019 Environmental Responsibility Report, Apple's global energy consumption in 2019 was 197 million terajoules, 75% of which came from the activities of manufacturing plants and suppliers. Global water consumption was 238 million cubic meters, of which more than 79% was used in manufacturing processes. Apple's products require the use of a large number of metals and chemicals to produce, and these materials generate significant energy consumption and environmental impact during mining, manufacturing, and transportation.

Apple's supply chain involves numerous suppliers and partners, and there are barriers to information flow and little transparency in the supply chain. This makes it difficult for management to identify and respond to supply chain risks and increases the company's operational risk. Barriers to information flow can also make the supply chain less responsive, leading to problems such as untimely capacity adjustments and inventory backlogs. There is also an impact on the company's sustainability plans, such as difficulties in monitoring and managing suppliers' environmental and social responsibility issues, which can affect the achievement of the company's sustainability goals.

3.2. Solutions

Apple has actively developed several approaches to address the current issues and challenges.

Firstly, they develop supplier responsibility codes and audit mechanisms to strengthen supplier management and oversight, ensure suppliers meet sustainability standards, and conduct regular audits and inspections.

Secondly, they also provide supplier training and support to help suppliers understand Apple's requirements and improve production efficiency and quality to ensure sustainability goals are achieved.

Besides, long-term, close partnerships are built with suppliers to help them better understand Apple's requirements, better manage their production processes and achieve shared sustainability goals.

Furthermore, Apple strives to promote the use of renewable energy, such as solar and wind power, by suppliers to reduce electricity consumption. Implement a global water management plan to monitor and manage water consumption in its supply chain, including water harvesting, use, and treatment, and actively promotes resource recovery and recycling, the use of recycled materials and material recovery in new products, and promoting practices such as zero-waste production.

4. The Key Success Factors of Apple's Sustainable Supply Chain Management

4.1. Leadership

The growth of a company depends, to a large extent, on the leadership of its leaders. When it comes to Apple, it is natural to mention Steve Jobs. Musk points out that Apple owes its wealth to leadership, as he says, "Leadership can make all the difference in the world." Since Steve Jobs returned as CEO in 1997, Apple's revenues have grown by 821%, with an annual growth rate of 18.6%, and its stock market value has soared by 8,524% [11]. Jobs has not only played a major role in the development of Apple but has also influenced the entire technology industry. His management philosophy includes the pursuit of excellence, focus on user experience, insistence on innovation, and collaborative working. This has laid the foundation for Apple to become an industry leader and has been the key to Apple's success.

4.2. Supply Chain

In addition to its leadership, Apple owes its success to the management of its supply chain. For Apple, the supply chain is the lifeline. Apple is committed to transparency, stewardship, and social responsibility in its supply chain and has taken several steps to ensure a sustainable supply chain. This includes building long-term partnerships with suppliers, developing and enforcing supplier compliance with supply chain guidelines, maintaining strict control over the entire supply chain, and exploring and applying new technologies to improve the efficiency and sustainability of the supply chain.

4.3. Social and Environmental Responsibility

Apple has been an industry leader in social and environmental responsibility. The company has implemented a sustainability strategy that includes reducing carbon emissions, promoting renewable energy, optimizing product design, and recycling materials. Apple is also committed to promoting social responsibility by firmly eliminating the use of child labor, strictly controlling workers' working hours, providing plans for worker training and development programs, and ensuring that suppliers' labor rights are respected.

5. Conclusion

This paper focuses on Apple's supply chain sustainability. Through a combination of literature research and case studies, it is found that Apple's supply chain sustainability success factors include leadership and commitment, supplier selection and management, resource and energy utilization, supply chain transparency and collaboration, and social and environmental responsibility.

The study shows that Apple has made significant progress in supply chain sustainability, but some issues and challenges remain, such as environmental pollution and resource consumption, labour rights protection, and supply chain transparency. To address these issues, Apple should strengthen its monitoring and control of supply chain management, promote the application of environmentally friendly technologies, improve employee welfare, and enhance cooperation and communication with suppliers. The shortcomings of this paper are that the research methods could be more diverse, such as adding field research or follow-up observations, in addition, the literature review could be more comprehensive and cover more relevant studies and cases, in addition, more specific cases and data could be provided to support the specific strategies and measures in Apple's supply chain sustainability, at the same time, Apple's supply chain sustainability is an evolving process The literature and cases chosen for the thesis may not cover the latest developments and changes.

Future research could explore in depth the social and environmental responsibility of Apple's supply chain management, further investigate strategies and methods for supply chain transparency and collaboration, explore the application of emerging technologies in supply chain sustainability, and the challenges and solutions of multinational companies in global supply chain management. In addition, comparative studies on supply chain sustainability in other industries and companies can be conducted to facilitate the sustainability process of the whole industry.

In conclusion, the study of Apple's supply chain sustainability provides insights into its success factors and challenges and offers valuable insights for companies and governments. In the context of increasing global economic and environmental urgency, supply chain sustainability will become an important strategy for business development, making a significant contribution to the achievement of economic, social and environmental sustainability goals.