3.1 Value chain

The value chain is given by a set of intertwined processes that work for the compliance with customer needs. They are divided into primary and support needs, each with a specific function. As a result of the above, the value chain is a tool that allows the organization to establish strategies based on the analysis of its own realities and consolidate an improvement plan to constitute a comparative and competitive advantage. ^{Porter (1985)}, affirms that the value chain is an instrument for the analysis of competitive advantages, since that studies all the activities carried out by the company and its way of interacting. This allows dividing the company into activities in order to analyze the behavior of costs to better understand the competitiveness advantage, since as a whole it can be analyzed much easier and in this way, obtain the advantage of each of the company’s activities.

^{Quintero and Sánchez-Carreño (2006)}, state that a way of articulating the activities is the value chain, since it determines the value for customers and the support of each one of them to reflect the evolution of the business, as well as internal operations. In like manner, Efiempresa (2018), establishes that the value chain proposes a sketch for the diagnosis of the position of the organization against its competition, being, in turn, an effective way to define the actions that must be developed to obtain a competitive advantage that is sustainable. ^{Arnedo-Severichi (2012)}, mentions that the value chain is made up of different processes that represent the main costs of a business and that´s why companies seek to generate competitiveness efficiently, optimizing resources and improving processes.

In the same way, ^{Walters and Rainbird (2017)}, express that the value chain allows locating the sources of competitiveness, so it is important to consider the identification of the bases of the competitive advantages of the value chain. For this reason, it is essential that the entire chain system reach the level of competitiveness and not just one link, that is, the analysis of the value chain is fundamental to a value creation system. This instrument aids in the identification and evaluation of strategic options that provide competitiveness to organizations.

^{Walas-Trebacz (2015)}, states that the management of the value chain gives the opportunity to link the business strategy with the different processes of the company and thus cooperate in effective management, reducing costs and improving the efficiency of the components of the value chain. Also, ^{Nagy et al. (2018)}, clarify that each company must couple and articulate its value chain to its reality and its environment, without forgetting that work must be done to develop new capabilities. Therefore, ^{Wan and Wu (2016)}, establish that in order to obtain a place in the market, the processes must be managed internally, while ^{Gopal et al. (2020)}, conclude that, to be successful in the implementation of the value chain, important changes must be carried out in the company’s resources.

For ^{Alvarez-Indacochea et al. (2019)}, the business strategy must be reflected in the chain of value, since it extends from the suppliers’ suppliers to the clients’ clients and each activity or link has specific tasks.

Additionally, ^{Arce and Hernández (2008)}, state that these value-generating activities aimed at the same objective must be identified. Similarly, ^{Vivar-Astudillo et al. (2020)}, explain that each of these activities must have clear and measurable goals to cooperate in the generation of value. ^{Simatupang et al. (2017)}, indicate that the articulation of these activities allows to maintain and increase the value; while ^{Mukhtar and Azhar (2020)}, affirm that there must be an integration between each of the links so that, in this way, there are high-value co-creation skills. According to ^{Moreno-Loera et al. (2022)}, each component of the value chain must know how it works and what its contributions are to run them correctly. Meanwhile, for Martínez-Arroyo et al. (2023), each of the activities must fulfill certain functions without being overloaded, but directed towards the target objective of the value chain. In this sense, ^{Quintero and Sánchez-Carreño (2006)}, propose the value chain as a strategic tool that allows companies to manage those activities that contribute to giving value and pontetiate those that can be improved or eliminated. In view of the above, the analysis of the value chain leads to adapting the company’s offer in order to meet the needs and expectations of the client, thus increasing the value for the final consumer. Along the same lines, the design of the value chain is relevant, since it gives a management contribution as a strategic tool (^{Borja, 2002}). Simultaneously, ^{Liu et al. (2018)}, stand out on the analysis of the chain, which must be relevant to analyze the strategy, structure and rivalry of the company, since these factors describe subjects of added value that contribute to the design or structuring of the value chain.

A chain must not only generate value, but it is important that it be sustainable over time. Accordingly, ^{Bokolo (2019)}, expresses that it is relevant to establish friendly value chains with the environment. In this sense, ^{Damite and Vallejo (2017)}, affirm that a sustainable value chain must be constantly innovating and have different actors to generate. Innovation will become a significant axis for the value chain, where investment in technology and innovation are options to maintain and improve it (^{Liang, 2021}). Further, ^{Rasanjani et al. (2019)}, referring to industry 4.0, they affirm that it plays an important role in the value chain, since it facilitates the generation of competitive advantages.

3.2 Competitiveness

Competitiveness is the ability of a company to execute strategies that are established to benefit, increase and maintain market share; besides generating a differentiation with respect to the competition of the product or service they offer and working in favor of the customer’s satisfaction and his needs much better than working in favor of the competitor. The word competitiveness has its origin in compete, as defined by ^{Moya (2019)}, “to compete with two or more people, aspiring to each other and others committed to the same thing”; while competition is defined as a “dispute or contention between two or more subjects about something”.

Similarly, ^{Porter (1985)} establishes that competitiveness is the ability of a company to manufacture and market products and services in the best conditions of quality, price and opportunity than its competition. ^{Miranda (2012)}, states that there are two types of competitiveness, the external and internal. The first one is the gradual ability to take advantage of certain conditions of competitiveness of the environment and obtain achievements in the context of the market, in order to achieve an outstanding entrepreneurship performance to get a place and acceptance in the market. While the second one is the one that contributes to increasing and sustaining the degree of competitiveness and performance of the company’s internal resources.

^{Porter (2015)}, affirms that the objective of the competitiveness model is to calculate the profitability of the sector, analyzing the competitiveness taking into account five forces: the existence or entry of substitute products, rivalry between competitors, the threat of new competitors, the bargaining power of suppliers, and the bargaining power of customers. Correspondingly, ^{Jimenez (2006)}, states that a competitiveness model must be based on the manager’s management in each of the areas and aspects of the organizations. This author states that between the value chain and competitiveness there is a connection, so the approach of a competitiveness model based on the value chain would provide organizations with a useful tool to obtain strategies for different links or activities. The activities, when articulated, generate a competitive advantage over direct competitors, in addition to providing continuous improvements in different aspects, such as the acquisition of position, growth and performance in the market in the medium and long term.

^{Strakova et al. (2018)}, express that competitiveness depends directly on the environment where the company is found, since the level of competitiveness can vary depending on the constants changes in the economy. In the same way, the competitive advantage of companies diversifies and adapts to the current economy (^{Jun & Rowley, 2019}), so that companies can generate value internally with trained and appropriate human capital (^{Wang & Thangavelu, 2021}), that being the case, ^{Bangun et al. (2017)}, recommend investing in human capital. Also, ^{Cho and Jun (2021)}, affirm that value is also generated internally with the investment in technology and innovation which contribute to the generation of competitive advantages. On the other hand, ^{Paiva et al. (2020)}, express that innovation and research contribute to the development of companies. In contrast, ^{Jaroenwanit and Daowadueng (2021)}, state that other intrinsic variables such as knowledge management, operational efficiency and focus on the market, among others, contribute to competitiveness in a positive way.

Defining a company’s competitive strategy is relevant in terms of its survival and the market share. In this sense, ^{Arce and Hernández (2008)} highlight the processes that generate value and costs must be identified, in order to advance the correct actions in the strengthening of the strategy and the organization. For ^{Tanrattanaphong et al. (2020)}, the competitive strategy consists of adapting to the different requirements presented by different entities and thus seek to comply with what is required by the client. In addition, the company must interact with the environment for the constant search for strategic opportunities and allow it to be prepared for new challenges, becoming a competitive company in the market and in front of its competitors (^{Šnircová et al., 2016}).

3.3 Value chain competitiveness

The value chain is a relevant pillar in the generation of competitiveness, its structure allows intertwine different activities that together and directed towards the same end contribute individually for the creation of company value. Additionally, it is a tool that cooperates for the analysis of competitiveness and the creation of a competitive strategic model, in addition to acquiring the ability to execute the appropriate strategies for each organization, which allows it to satisfy the needs of end users.

^{Straková et al. (2018)}, establish that the value chain plays an important role in the generation of competitiveness, profitability and sustainability of companies, besides being an excellent analysis tool that guarantees a high level of competitiveness and cooperation in the creation of corporate strategy. In like manner, Lombanma (2011) proposes the value chain as a comprehensive and flexible alternative for the analysis of business competitiveness. What’s more, Strakpová et al. (2021a), found that companies must evaluate the effectiveness of their strategies and coupled them, for which, the value chain is a tool that allows the design of a model of competitive business. To fit into the environment, ^{Cheng (2021)}, affirms that it is by restructuring the processes of the value chain according to their environment, how competitiveness is improved in the organizations.

The value chain is a pillar of relevance for the generation of competitive advantages, as establishes ^{Arnedo-Severichi (2012)}, who affirms that it must be known and analyzed in depth so that there is competition in the organization. For this reason, ^{Straková et al. (2021b)}, consider that it is necessary to have an original value chain, since this is in charge of generation added value, maximize potential and minimize costs; in addition, this approach provides companies with a high competitiveness in the long term, that is, it is sustainable. Likewise, for ^{Bokolo (2019)}, a chain of sustainable value depends on internal operating performance and also goes hand in hand with the environmental theme. Considering how competitiveness is integrated so that organizations find in it differential aspects, ^{Simatupang et al. (2017)}, propose the value chain as a set of activities interlaced with each other with the function of maintaining value. Along, ^{Lie et al. (2018)}, raise the relevance of analyzing the relationships between these activities in the supply chain value with which we cooperate to generate and improve competitiveness. Likewise, ^{McColl and Moore (2013)}, consider that the connection and interactivity among the activities contributes to the implementation of the value chain and it is an important factor.

^{Abid et al. (2020)}, highlight the importance of the existence of relationships of trust between the participants in the value chain for maximum use and, in this way, develop improvements and innovation, which influence competitiveness. Meanwhile, for ^{Mukhtar and Azhan (2020)}, coordination between the functions of the value chain is a source of competitiveness and co-creation, what’s more, generating more solid and robust networks, which gives the advantage of creating very particular singularities and difficulties to imitate. For Kueo-Ling et al. (2001), through the value chain it is possible to acquire a utility from each supplier and each competitive unit, up to the target market. ^{Antonio and Griffith (2017)}, affirm that it is pertinent that there is a coordination along the value chain from market research to balancing requirements of the client, which helps to improve and maintain competitiveness, as well as the efficiency of the chain of value. This is true for the sale of products and also for services. As mentioned by ^{Gopal et al. (2020)}, services must move along the chain accompanied by an absorptive learning capacity. It is important to emphasize that each unit or activity in the chain has its role and its function within the process, for this reason ^{Samamé-Castillo(2019)}, considers that there must be a relationship among the activities for the chain with structural, administrative and financing assistance to strengthen competitiveness.

As stated by ^{Khubana et al. (2022)}, the productivity of the value chain contributes to shared value, to competitive advantage and sustainability performance, which generates value to the organization. ^{Boffa et al. (2021)}, take into consideration that the integration of the value chain cooperates for an increased competitiveness, which is useful for small companies that want to acquire and maintain their competitive advantage. ^{Nzivo (2011)}, came to the conclusion that the value chain is an important basis for the generation of competitiveness, which also guides compliance with the requirements and needs of the client, accompanied by a reduction in the cost of operation. In the same way, ^{Gao and Zhang (2018)}, clarify that the value chain has the capacity to increase management and strengthen links by actively promoting competitiveness.

3.4 Proposed model

The review of the literature allowed us to establish that, although there is a wide panorama of research on related topics, there is no model of competitiveness based on the chain of value that meets the characteristics and specifities of the sector and in particular on coke as an object of study. This section proposes its own competitiveness model that recognizes the gaps of literature and the particularities of the sector, considering that coke mining industry is fluctuating (see figure 1). This implies the need to generate long-term competitiveness and maintaining the sector in the market under the articulation of different tools and skills, both internal or external.

Figure 1 Proposal for a competitiveness model based on the value chain for the coker sector. 

Figure 1 shows that the value chain is made up of businessmen and social actors, moreover, some primary and support activities; with the articulation of these elements result in competitiveness. In this model, the value chain creates a process of inputs, processes and outputs, which in turn generates feedback from the businessmen and social actors, where each of them fulfill important functions. As ^{Pirez (1995)} says, the social actors are units of real action in society, which operate as executors and decision makers that affect the reality of the community. They are within the social base that act as individuals or collectives, In the model, social actors are those who interfere in the process and are represented by the community, the academy, the government, the unions and the businessmen. Each actor contributes from their perspective and position to the development of a value chain supply in the coking sector and contributes significantly to the generation of competitiveness. Businessmen are represented by those who, directly or indirectly, are associated with coke. The direct ones are the customers or buyers of the final product and the supplies’ suppliers. The indirect ones, are those that although aren’t directly associated with the final product, they are part of the production process, such as: transportation, insurance companies and public services, among others.

In the value chain of the coking sector, primary and support activities are found. The primary ones are those that provide the greatest value to customers, among which we have the internal logistics, which is where the process begins with purchase, reception and management of the inventories of the raw material; the operation, which is the transformation of coal to coke passing through solera ovens type at more than 900°C (ACIS, 2022).; external logistics is responsible for transporting and delivering the raw coke to customer. As well, sales and customer service are the areas in charge of marketing and sale of coke, as well as customer loyalty and search for more customers.

Support activities are those that reinforce the primary activities and add value to the product indirectly. These activities are made up of the infrastructure, at which it has administrative control such as the accounting, financial area and quality control of the raw material acquired, since the quality of the final product directly depends on it. The management area is another support activity, since it is responsible for hiring and maintaining the right personnel for the execution of each task of the process. The technological development area is also integrated here. It provides to the information systems, a track of the process and allows updating technology for continuous improvement. The last support activity is the purchasing area, which supplies from the raw material with quality standards to everything necessary for an optimal coke production. The competitiveness model based on the value chain of Figure 1, also proposes in a clearly way a dependent variable that is competitiveness and an independent variable that is the chain of value. Moreover, facilitator and support variables are integrated by the businessmen and social actors. Therefore, businessmen significantly influence the value chain, generating information that allows us to constantly assume the improvement of both the process as well as the final product. Social actors also become a fundamental part within the proposed model, since they provide very useful information for decision-making based on expectations, trends and perspectives.

The proposed model is a predictive bet on the cause-effect relationship between the value chain and its incidence of the competitiveness of the coking sector. In this sense, a reaction of the independent variable gives rise to an effect on the dependent variable, like the primary and support activities that have an incidence on the dependent variable or competitiveness. The behavior of the businessmen and social actors in line with the performance of the primary and support activities are decisive in producing competitiveness for the coke sector. As a consequence, these activities constitute a robust model with internal validity (validity and reliability of the instruments) and external validity (possibility of being used in other sectors or spaces), which provide the studied sector with a tool for the strengthening and competitiveness.

The literature review allowed setting up that all the activities or links of the value chain must be directed towards a common objective and be articulated to achieve compliance which, generally speaking, is customer satisfaction. Also, to satisfy customer is an important variable in the development of competitiveness for any organization, since it offers aspects that allow us to work for his satisfaction.