Conceptualized by Harvard Business School professor Michael Porter in 1985, Porter argues that "every business is a collection of activities that go into the process of designing, producing, selling, sending, and supporting its products. All these activities can be indicated by a value chain." Value creation in an enterprise is constituted through a series of activities that can be categorized into basic activities, which include internal logistics, production operations, external logistics, marketing and sales, and services; and auxiliary activities, which include purchasing, technology development, human resource management, and enterprise infrastructure. These different but interrelated production and operation activities constitute a dynamic process of value creation, i.e. the value chain.　　The value chain is ubiquitous in economic activities. There is an industry value chain between upstream and downstream associated enterprises, the linkage of business units within an enterprise constitutes the value chain of the enterprise, and there is also a value chain linkage between business units within the enterprise. Each value activity in the value chain will have an impact on how much value the enterprise can ultimately realize.　　Porter's "value chain" theory reveals that the competition between enterprises is not only the competition of a certain link, but the competition of the whole value chain, and the comprehensive competitiveness of the whole value chain determines the competitiveness of enterprises. In Porter's words: "The value in the mind of the consumer consists of a series of internal material and technological specific activities and profits of the enterprise, when you compete with other enterprises, in fact, it is a number of internal activities in the competition, rather than the competition of a particular activity."　　The Concept and Composition of the Value Chain In order to survive and grow, an enterprise must create value for its shareholders and other interest groups, including employees, customers, suppliers, as well as the region in which it operates and related industries. If we open the "black box" of "enterprise", we can decompose the process of creating value into a series of different but interrelated economic activities, or "value-added activities", the sum of which is the value chain. "The sum of these activities constitutes the "value chain" of an enterprise. Any enterprise is an aggregate of activities carried out in the design, production, sales, delivery and after-sales service of its products. Each business management activity is a link in this value chain. The value chain of an enterprise and the way in which it carries out individual activities reflects the history of that enterprise, its strategy, the way in which it implements that strategy, and the main economics of the activity itself. The value chain can be divided into two main parts: basic value-added activities and ancillary value-added activities. The basic value-added activities of an enterprise are the "production chain" in the general sense of the term, such as the supply of materials, the development of finished products, the operation of production, the storage and transportation of finished products, marketing and after-sales service. These activities are directly related to the processing flow of commodity entities. The auxiliary value-added activities of the enterprise, including organization construction, personnel management, technology development and procurement management. Both technology and procurement here are broadly defined, and can include both productive technology and non-productive development management, e.g., decision-making technology, information technology, and planning technology; procurement management includes both the production of raw materials and the management of other resource inputs, e.g., the hiring of relevant consulting firms to carry out advertisement planning, market forecasting, legal consulting, information system design, and long-term strategic planning for the enterprise. The links of the value chain are interrelated and mutually influential. The good or bad management of one link can affect the costs and benefits of other links. For example, if a little more cost is spent on purchasing high-quality raw materials, the production process can be reduced, with fewer defective products and shorter processing time. While each link in the value chain is related to the others, the extent to which a link can influence the value activities of the others is highly dependent on its position in the value chain. The value activities of an enterprise can be categorized as "upstream" and "downstream" according to the flow of product entities through the various links of the value chain. Among the basic value activities of an enterprise, material supply, product development and production operation can be called the "upstream link", while storage and transportation of finished products, marketing and after-sales service can be called the "downstream link". The center of economic activities of upstream link is the product, which is closely related to the technical characteristics of the product; the center of downstream link is the customer, and the success or failure mainly depends on the characteristics of the customer. Whether it is productive or service industries, the basic activities of enterprises can be expressed by the upper value chain, but the specific composition of the value of different industries is not identical, and the importance of the same link in each industry is also different. For example, in the agricultural industry, due to the relative simplicity of the product itself, the competition is mainly expressed as price competition, generally less need for advertising marketing, and the requirement for after-sales service is not particularly strong, accordingly, the downstream link of the value chain is relatively secondary to the overall effect of the enterprise's operation; while in many industrial machinery industries and other industries with high technological requirements, the after-sales service is often the key to success or failure in the competition. In many industrial machinery industries and other technically demanding industries, after-sales service is often the key to the success or failure of competition. Second, the value chain and the enterprise's competitive advantage "value chain" theory is the basic point of view, in an enterprise's many "value activities", not every link to create value. The value created by an enterprise actually comes from certain specific value activities in the enterprise value chain; these real value-creating business activities are the "strategic links" of the enterprise value chain. The advantage of an enterprise in competition, especially the advantage that can be maintained for a long time, in the final analysis, is the advantage of the enterprise in some specific strategic value links of the value chain. The monopoly advantage of the industry comes from the monopoly advantage of some specific links in the industry, and by seizing these key links, the whole value chain is also seized. These strategic links that determine the success or failure of business operations and benefits can be product development, process design, marketing, information technology, or recognize the management, etc., depending on the different industries. In the high fashion industry, this strategic link is generally design capability; in the cigarette industry, this strategic link is primarily advertising and public **** relations strategy (i.e., how to deal with various governmental and consumer organization smoking cessation efforts); and in the restaurant industry, this strategic link is primarily the choice of restaurant location. Although, as mentioned earlier, different industries have different value chains and the role of the same link varies from industry to industry, large-scale enterprises, such as multinational corporations (MNCs), can diffuse and transplant their core competencies in related industries through the key links in the value chain, thereby enhancing the competitive advantage of enterprises, especially MNCs. In their international marketing activities, TNCs have the economy of scope effect of global cross-industry marketing. This economy of scope effect is the multinational corporation through the optimal breadth (scope) of the use of generic elements and resources and obtain. Such generic factors can be generic production equipment, management experience, marketing skills and research and development capabilities. Since the existence of generic elements can be found in almost every link of the value chain, when the key link in the value chain, i.e., the core competence, of two industries requires the same generic elements, the MNC spreads its core competence in one industry to another related industry, which transforms the economy of scope effect into an economic advantage of scope. Therefore, the advanced knowledge, experience and skills gained by TNCs in marketing and communication activities in one industry can be transferred to other related industries without great additional investment. Such as the United States of America's Philip I. Morris Company is a famous tobacconist, created the Marlboro this