Research on Sustainability Evaluation of China’s Coal Supply Chain from the Perspective of Dual Circulation New Development Pattern

Abstract

The critical strategic plan of the new dual circulation development pattern provides new strategic opportunities for the modernization of China’s coal supply chain. This paper presents new ideas for the sustainable development of the coal supply chain. To significantly improve the systematic and scientific evaluation of the sustainable development of China’s coal supply chain under the background of “dual circulation”, a sustainability evaluation index system for the coal supply chain is proposed, which contains five dimensions. Furthermore, an evaluation model is built based on multi-granularity unbalanced decision-making and TOPSIS theory. On this basis, an empirical study was carried out using a coal supply chain in China as an example, and scientific and effective development countermeasures are presented, which effectively promote new development and build unique competitive advantages for the energy industry.

1. Introduction

Currently, China’s economic growth model is gradually changing from an extensive-type with high speed to an intensive-type with high quality [1]. China is building a new development pattern with domestic and international circulations that reinforce each other. The basic model of “dual circulation” is that domestic circulation is the main body, and international and domestic dual circulations promote each other’s development. At present, China has entered the late stage of industrialization. The industrial chain, supply chain and consumer market have the conditions to meet the requirements of economies of scale and agglomeration, and have the basis for economic efficiency that relies mainly on domestic economic cycles. Therefore, what “dual circulation” needs to do is to shift the focus of industries and technologies to China, and make foreign industries and markets more dependent on China with strong domestic consumption and high-quality products in China, thereby realizing “internal promotion” [2]. The essence of “dual circulation” is to build a domestic circulation system in China that can not only integrate into international circulation independently, but also find power and support from it. The most decisive factor in establishing a smooth economic circulation under the new pattern is whether a sustainable supply chain can be constructed.

Coal is one of the primary energy supplies that supports China’s economic development. Its supply chain covers the “mining, processing, transportation, distribution, and consumption” of coal. Factors such as the current status of coal stocks, market demand forecasts, the operation of production facilities, coal sales, and the processes of upstream and downstream partner companies will directly or indirectly affect the sustainability of the coal supply chain. Currently, there are some problems with the evaluation of the sustainability of the coal supply chain, such as the limitation of the evaluation indexes, the weakening of evaluation intensity, and the bias of the evaluation results, which can no longer meet the new requirements of the development of “dual circulation”. Under the background of “dual circulation”, the current coal supply chain should focus on driving innovation and development, supported by a higher level of opening to the outside world. The coal supply chain should promote a higher quality domestic demand balance between China’s supply and demand, promote the high-quality development of China’s manufacturing industry, and create new opportunities and foster new opportunities in the construction of a domestic and international dual circulation development pattern [3].

Therefore, based on the new “dual circulation” development pattern, and based on domestic and international markets of the coal industry, it is of great theoretical and practical significance to research the sustainability evaluation of China’s coal supply chain. On the one hand, we aim to guide the relevant enterprises in the supply chain to formulate and adjust strategies, and improve the cognitive pattern of the cooperating subjects. On the other hand, we aim to promote the integration and optimization of internal and external resources in the coal supply chain and accelerate the exploration of a new model for the sustainable development of the coal supply chain.

2. Literature Review

As people pay more and more attention to the impact of carbon emissions on the environment and social responsibility, the concept of sustainability has been gradually introduced into the coal supply chain, in order to achieve the goal of sustainable development of the coal supply chain. Domestic and foreign scholars have done little research on coal or coal-related products from the perspective of their carbon footprint. From coal exploration, the entire life cycle of coal goes through stages such as coal mining, washing, transportation, processing, transformation, consumption, and waste disposal [4]. In the processing of coal output, re-export or final use is the forward link. Coal exploration, production, and processing can lead to the emergence or expansion of new production facilities and services to support coal production inputs, which are backward links [5]. Consider Green Supply Chain (GSC), Sustainable Supply Chain (SSC) and Low Carbon Supply Chain (LSC) based on the concept of environmental principles, sustainable development and zero emissions. The carbon footprint assessment was used to investigate the coal supply chain, covering the main concerns of GSC, SSC, and LSC, such as green production, social responsibility, low carbon emissions, etc. [6,7]. Sustainable coal supply chain management must not only focus on carbon emissions, but is also an innovative supply chain, and technological innovation of different coal products helps to reduce their carbon footprint in the supply chain [4]. Carbon footprint results are highly relevant to nationally applied environmental policies and should be considered when structuring international action on climate change [8].

Many domestic and international scholars have conducted extensive research on the sustainability of the coal supply chain. Rindasari (2016) [9] used a combined SIA and CSA approach to analyze and assess the social sustainability of the coal industry. Cao (2017) [10] searched China’s coal industry reform policies for sustainable development and proposed that a socially, economically, and environmentally compatible regulatory framework is needed for the coal industry to achieve sustainable development. Du (2020) [11] suggests that China should adequately control the amount of imported coal trade due to the lack of “external demand” under the new epidemic. Shen (2021) [12] proposed that low carbon and sustainability is the inevitable development trend in the supply chain of the coal industry. By studying the impact of emissions reduction policies on the coal industry in the context of dual carbon, Liu (2021) [13] proposed a high-quality development path for the coal industry to reduce carbon, control carbon, and use carbon in the future. Savin (2021) [14] analyses the prospects for sustainable development of the coal industry in a region.

At the same time, many research results have been achieved in the field of evaluation of the coal supply chain. Ding and Wang (2007) [15] proposed, for the first time, a performance evaluation system for the coal supply chain in three dimensions: natural geological conditions, internal to the company, and external to the company, and introduced social benefit indicators for coal companies. Huang (2010) [16], Li (2013) [17], and Song (2013) [18] introduced the concern of the coal supply chain for the environment. Li (2017) [19] conducted an empirical study on the performance evaluation system constructed using the criteria of “strategic partnership, balanced supply capacity, information efficiency, business process, financial performance, and customer satisfaction” through the IAHP-Entropy comprehensive evaluation method. Wen (2018) [20] studied the collaborative system of domestic coal supply chain management based on the analytic hierarchy process. Ghadimi (2019) [21] constructed environmental performance indicators for the coal energy supply chain based on a life-cycle approach and applied them to the Chinese coal energy supply chain. Sha (2021) [22] constructed a coal supply chain performance evaluation system with the objectives of “high efficiency, low cost, high quality, appropriate quantity, safety and environmental protection”. Yuan (2021) [23] provided a “meta-rule” to build an evaluation system framework for the management of the coal supply chain, starting from four aspects: green governance structure, green governance mechanism, green governance effectiveness and green governance responsibility. Zhao (2021) [24] studied the coal supply chain from the perspective of high-quality development and proposed a sustainable development dimension for performance evaluation.

In summary, most of the current sustainability evaluation indicators for the coal supply chain are carried out in three aspects: economy, environment, and society, focusing more on the unification of economic and environmental benefits. However, the new “dual circulation” development pattern places higher demands on the sustainability of China’s coal supply chain. The new low carbon environment has given new meaning to the sustainable development of the coal supply chain. The practice of carbon neutrality requires more social responsibility from companies in the supply chain. The security to effectively respond to supply chain disruptions is of even more significant concern.

3. Basic Framework of Evaluation Indexes System

Currently, the sustainable coal supply chain is the key to the sustainable development of the coal industry chain, and has gradually become a national strategy. Improvement and transformation of the coal industry itself requires the construction of a supply chain, and the structure of a sustainable coal supply chain is an effective way to upgrade and enhance the competitiveness of the coal industry. Under the new development pattern of “dual circulation”, the integration of domestic and international coal markets has laid a solid foundation for the sustainable development of the global coal supply chain. To effectively integrate domestic and foreign resources to create an international coal supply chain requires the combination and innovation of the traditional supply chain model and “dual circulation” development, which will inject new impetus into the realization of high-quality coal and the sustainable development of coal.

China’s coal supply chain mainly includes three significant links: coal source, circulation, and consumption, from resource acquisition to coal production, transportation, coal processing, and utilization, where:

(1)

Coal source refers to obtaining coal resources through national allocation and purchase of coal resources in the coal resource market, and then converting coal resources into commercial coal through washing, coal blending and other links.

(2)

Circulation refers to the completion of coal circulation services through intermediaries, carriers, and other service providers.

(3)

Consumption refers to the use of coal as fuel or raw materials to carry out production and business activities.

In the coal supply chain, the coal intermediary is the leading enterprise in the supply chain, and the upstream links the coal procurement network composed of multiple coal production enterprises; the downstream links a coal distribution network consisting of various coal distribution companies and end customers; facing the midstream, it links a circulation service network consisting of several enterprises with functions such as transportation, processing, warehousing and capital services. The specific process is as follows:

The coal broker first obtains the coal demand information from the coal end customers, including demand quantity, coal type, coal quality requirements, demand time, demand location, target price, etc.; then looks for coal sources from your own coal procurement network corresponding to the demand information; then, after finding the coal source, you can purchase it on your behalf, or you can negotiate directly with the buyer and the seller; after the procurement contract is signed, the coal broker uses professional distribution service enterprises such as coal processing enterprises and coal transportation enterprises in their robust distribution service network to provide comprehensive services, such as processing and transportation of the coal output by coal production enterprises according to the needs of the coal end customers; finally, according to the individual needs of the coal end customers, the correct quantity and quality of standard coal will be delivered to coal customers at the proper time and place, and comprehensive service fees will be charged. It can be seen from the entire coal service supply chain operation process that coal intermediaries play a coordinating and management role in the operation of the entire supply chain [25].

Since the “13th Five-Year Plan”, high-quality development has been continuously valued. Therefore, the construction of the coal supply chain sustainability evaluation index system should reflect the main purpose of high-quality development when selecting relevant indicators, which should include relevant purposes such as innovation, greenness, openness, sharing and sustainable development. This is not only a supplement to the coal supply chain evaluation index system, but also conforms to the real-time development of the coal supply chain in the future. According to the new requirements of the new “dual circulation” development pattern, based on the sustainable development framework of “economy-environment-society”, combined with the new development concept, this paper fully considers the three links of China’s coal supply chain, deeply analyzes the process structure of coal supply chain management, and adds indicators closely related to the sustainable development of the coal supply chain. A framework of a sustainable evaluation index of the coal supply chain with five dimensions of “economy, innovation, green, coordination, safety” has been formed. This is shown in Figure 1.

Economic development must be sustained and healthy without the need to proceed at an excessive speed, which is the premise and foundation of high-quality development. Innovation is the first driving force for development. At present, China’s economic development has three characteristics: speed change, structural optimization, and power transformation. However, China’s level of technological innovation is still far behind the international level. The formation of an economic system and a development model with innovation as the main guide and support must be accelerated. At the same time, as the first resource to support development, talents will jointly create new effective and sustainable global demand and lead the direction of world economic development. Being green is a necessary condition for sustainable development. The sustainable development of the coal supply chain is an important manifestation of the current high-quality development, and sustainable development is related to the future operation of the coal supply chain. Coordination is the inherent requirement for sustainable and healthy development. In the domestic and international dual circulation system, domestic circulation is the foundation and guarantee for international circulation. International circulation plays a role in driving and optimizing, and is the extension and supplement of domestic circulation. Coordination is a solid foundation for various entities in the supply chain and sound cooperation at home and abroad. Safety is the basic point for the healthy operation of the coal supply chain and the development of a good momentum. Therefore, security issues should also be put in an important position in development. All nodes in the coal supply chain have hidden dangers of safety problems, which will not only cause corresponding losses in the coal supply chain but also affect the reasonable operation of the coal supply chain.

The five-dimensional integrated coal supply chain sustainability evaluation index system of “economy-innovation-green-coordination-safety” interconnects and promotes each other. It is a collection with internal connections. Grasping the new development concept from the overall and internal connection and implementing the comprehensiveness and systematic nature of the supply chain index system can not only promote the effective control of the efficiency and cost of the entire supply chain in the operation process, but also achieve green safe sustainable goals.

Compared with the “economy-environment-society” sustainable development evaluation indexes framework, the five-dimensional integrated coal supply chain sustainable evaluation index system of “economy-innovation-green-coordination-safety” adds innovation and safety content, and more clearly clarifies the specific range of the three-element indicators of “economy-environment-society” [26]. Among them: the “economy” takes into account external circulation factors and reasonably analyzes and measures the level of transnational operations and the level of attraction of foreign investment. “Innovation” is aimed at the needs of intelligent coal mining, clean coal utilization, and enterprise management informatization. It promotes various innovative development methods for the coal industry. The “green” index has more content than environmental indicators, mainly adding space utilization intensification indicators and international environmental standard certification indicators. Compared to social hands, “coordination” considers the degree of international cooperation and the degree of information symmetry. “Safety” according to the current situation of China’s coal, is to ensure “production safety” and “management safety”. Through the sustainable evaluation of the coal supply chain, a new development orientation is provided to realize the strategic goal of high-quality development, and the ability of the coal supply chain to resist risks and improve efficiency.

4. The Establishment of the Evaluation Indexes System

By sorting the following scholars’ studies on the indicators of the evaluation of the sustainable coal supply chain (as shown in

Table 1. Sorting the indicators of sustainable evaluation of coal supply chain.

Author	Years	Index
Ding [15]	2007	Economic benefits (profitability, solvency, operational capability, and development capability), and social benefits (contribution capability, safety benefit rate, mortality rate per million tons, and environmental protection)
Huang [16]	2010	Production cycle period, number of accidents (annual number of safety accidents), and pollutant discharge (degree of coal dust flying, coal combustion smoke and dust emissions, and total SO2 emissions)
Huang [28]	2010	Low-carbon and sustainable development capability indicators (ratio of new technology R&D personnel, growth rate of new technology R&D expenses, and CO2 emission growth rate), and personnel performance indicators (ratio of undergraduates and above)
Li W [29]	2011	Balanced supply capacity (coal quality stability, and emergency supply capacity), information efficiency (accuracy of information transmission), and business process (average production cycle of products)
Wang [30]	2013	Innovation ability (proportion of technology investment, and R&D investment ratio), authoritative organization certification (proportion of ISO enterprise certification, and ISO green enterprise certification ratio), and environmental protection practice (use of recyclable materials)
Dai [31]	2015	Environmental performance (recyclable material usage rate, and resource recovery and reuse rate)
Zhu [32]	2016	Supply chain strategy matching, supply chain coordination, equipment and facility capabilities, investment in science and education, and innovation capabilities
Zhao [24]	2021	Talent (proportion of personnel with educational backgrounds, and number of personnel in training), R&D (proportion of R&D personnel, total R&D expenditure), innovation (number of new patents), environmental protection, safe production

), based on the five-dimensional framework of “economy-innovation-green-coordination-safety” in this article, the sustainable evaluation indicator system of China’s coal supply chain is constructed according to comprehensive, systematic and scientific principles [27]. To accurately evaluate the coordinated development of all aspects of China’s coal, based on the system of coal supply chain sustainability evaluation indexes, this article comprehensively considers the new development pattern of “dual circulation”. It demonstrates the following indicator system for the sustainable evaluation of the coal supply chain that covers both domestic and international aspects, as shown in

Table 2. Sustainability evaluation indexes of coal supply chain under the new development pattern of “dual circulation”.

Selection of Dimensions	Specific Indicators
Economy	E1 Asset stock level E2 Overall profitability E3 Sustainable development capacity E4 Level of transnational operation E5 Level of foreign investment attraction
Innovation	I1 Efforts to attract high-caliber talent I2 Research and development investment efforts I3 Management system intelligence level I4 Fully localized level of intellectual property I5 New product development cycle
Green	G1 Major air pollutant emissions and carbon emission levels G2 Industrial waste water, gas and residue treatment level G3 Levels of resource recovery and reuse G4 Degree of space-use intensification G5 Degree of certification to international environmental standards
Coordination	C1 Degree of alignment of upstream and downstream targets C2 Degree of upstream and downstream risk sharing C3 Degree of upstream and downstream information connectivity C4 Degree of international cooperation relevance C5 Level of international information symmetry
Safety	S1 Stability of coal supply S2 Safety system equipment reliability S3 Degree of internal information security protection S4 Level of preparedness for emergency planning S5 Overseas warehouse construction situation

.

(1) The economic dimension covers five indicators: asset stock level, overall profitability, sustainable development capacity, level of global operation, and level of foreign investment attraction. Asset stock refers to all existing asset resources in the entire coal supply chain, including current assets and non-current assets [33]; overall profit refers to the general level of profit obtained by enterprises at each node in the coal supply chain; sustainable development represents the development potential of the coal supply chain not only to meet the current needs of its own development, but also to develop in harmony with the environment; transnational operation refers to the transnational operation activities carried out by the domestic coal supply chain through foreign direct investment [34]; attracting foreign capital refers to attracting foreign capital or foreign investors to invest in the domestic coal supply chain.

In particular, E1–E3 measures the domestic economic performance and development potential of the relevant subjects in the coal supply chain from the three perspectives of “stock-flow-quality”. E4–E5 focuses on the relevant issues and measures the extent to which they are economically linked to the global coal market from the perspective of “going out-bringing in” in the international market. It is an important way to build a higher-level opening system and realize domestic and international dual circulation [35].

(2) The innovation dimension covers five indicators: efforts to attract high-caliber talent, research and development investment efforts, management system intelligence level, fully localized level of intellectual property, and new product development cycle. Intelligence of the management system refers to the ability of the coal supply chain management system to think about the input information [36]; R&D investment refers to capital investment and other soft investment of the coal supply chain in the R&D of innovative products in the supply chain [37]; attracting high-caliber talents refers to a series of measures to introduce talents made by the main body of the coal supply chain; the new cycle of product development refers to the time from research and development to delivery of a product; the level of complete localization of intellectual property rights refers to the proportion of domestic related technology patents of the main coal supply chain in the total.

I1–I4 explore innovations in organizational structure, starting with the management and production side of the subjects involved. Further, the level of innovation is measured in three specific areas: R&D investment, talent introduction, and product iteration. The selection of I5 and its evaluation requires a careful consideration of the domestic and international element proportions of the relevant technology patents.

(3) The green dimension covers five indicators: primary air pollutant emissions and carbon emission levels, industrial wastewater, gas and residue treatment level, levels of resource recovery and reuse, degree of space-use intensification, and degree of certification to international environmental standards. Main air pollutant emissions and carbon emission levels refer to air pollutant emissions and carbon dioxide emissions [38]; the three industrial wastes refer to the waste gas, waste water and waste residue generated in the industrial production process [39]; the level of resource recovery and reuse refers to the mechanism and measures for recycling and reuse of waste after recycling; the intensification of space utilization refers to the rational allocation of resources and centralized input of production materials, to achieve a means of improving the utilization of space; the degree of international environmental standard certification refers to the degree to which the environmental standards of coal supply chain-related enterprises are in line with international standards.

G1–G4 are based on the specific coal supply chain industrial process of “three wastes emission—three wastes treatment—recycling—intensive use”, and measure the quality of environmental use and protection by the relevant subjects in the domestic coal supply chain. The G5 reflects the international green quality requirements for the industry.

(4) The coordination dimension covers five indicators: the degree of alignment of upstream and downstream targets, the degree of upstream and downstream risk sharing, the degree of upstream and downstream information connectivity, the degree of relevance of international cooperation, and the level of global information symmetry. The degree of consistency between the upstream and downstream goals refers to whether enterprises at each node of the coal supply chain have the same guidelines and strategic plans; the degree of upstream and downstream risk sharing refers to the level of joint risk-taking of enterprises in each node of the coal supply chain with “equivalent responsibility and power”; the degree of upstream and downstream information connectivity refers to the level of information sharing across enterprises, systems, equipment and time and space among enterprises in each node of the coal supply chain [40]; the degree of international cooperation relationship refers to the closeness of cooperation between the domestic coal supply chain and related foreign enterprises; the degree of international information symmetry refers to the degree to which the domestic coal supply chain obtains information from the international market.

For supply chain coordination, the first step is to achieve coordination of objectives, told through the C1 index. Next, the specific role of coordination must be based on two main mechanisms of shared risk and shared information, expressed through the C2 and C3 indexes. Based on global markets, the coherence of the coal supply chain is reflected in the extent to which it is closely linked to global markets and the extent to which it has access to information about international markets, expressed through the C4 and C5 indicators.

(5) The safety dimension covers five indicators: stability of coal supply, safety system equipment reliability, the degree of internal information security protection, the level of preparedness for emergency planning, and the overseas warehouse construction situation. Coal source supply stability refers to the degree to which upstream coal suppliers guarantee a stable supply of coal; safety system equipment reliability refers to the degree of safety operation and the daily maintenance level of the equipment used in the coal supply chain [41]; the degree of emergency preparedness refers to the pre-preparation of the main coal supply chain for emergencies [42]; the degree of internal information security protection refers to the clarity of the information boundary of the coal supply chain and the degree of internal information privacy [43]; the construction of overseas warehouses refers to the level of international coal storage.

Regarding safety, the relevant parts of the coal supply chain need to ensure “production safety” and “management safety”. The former is in the form of coal supply safety, while the latter is in the form of operational safety of the equipment and internal management safety. In addition, risk prevention and control must be performed to minimize losses. When there is a shortfall in domestic coal supply, the international market must be actively used to make up for it, and the construction of overseas warehouses provides the security of the coal supply.

5. Weight Determination

The research on the sustainable evaluation index system of the coal supply chain in this paper focuses on determining the weight of the index and determining the priority of development, in order to play a guiding role in the strategic planning of the supply chain under the condition of limited resources. The coal supply chain itself is complex and uncertain, so the accuracy of the sustainability evaluation value is difficult to guarantee. Each evaluation expert is also limited by professional knowledge, social experience and the complexity of the reality, so the linguistic variables they evaluate show an unbalanced state, and the semantic granularity of linguistic decision-making information of different evaluation experts is not completely consistent. Therefore, the importance of each dimension evaluation index is calculated by the multi-granularity and unbalanced language decision-making method to solve the above problems and ensure the consistency and accuracy of the evaluation of the index importance by multiple experts. Then, the multi-objective hybrid ranking method in TOPSIS theory is used to accurately reflect the evaluation distance between each evaluation scheme [44]. When evaluating the sustainability of the coal supply chain, the importance of the indicators should be revised [45]. Considering that China’s economic development is based on the domestic cycle and other influencing factors under the current epidemic situation, the influencing factors of the indicators are determined to ensure the scientific evaluation of the sustainable development of the coal supply chain from the perspective of the new development pattern of “dual circulation”. The specific steps of evaluating the model are shown in Figure 2.

Take a dimension as an example: let the number of evaluation indicators contained in this dimension be $e$, and the number of experts participating in the evaluation be $m$. The i-th expert is denoted as $B_i$($i=1,2,\cdots m$), and the lth index is denoted as $E_l$($l=1,2,\cdots e$). The detailed operation process is as follows:

(1) Determine the weight ${\mu }_i$($i=1,2,\cdots m$) of each expert in the evaluation according to the difference between each expert’s social experience, professional knowledge and cognitive level;

(2) Using the multi-granularity unbalanced decision-making method, establish the initial decision matrix $R^{\prime }={(v_{il})}_{m\times t}$, and the language scale is expressed as:

$$S^{\left(k\right)}=\left\{s_{\alpha }^{\left(k\right)}|\alpha =1-k,\frac{2}{3}\left(2-k\right),\frac{2}{4}\left(3-k\right),\cdots 0,\cdots ,\frac{2}{4}\left(k-3\right),\frac{2}{3}\left(2-k\right),k-1\right\}$$

(1)

Among them, $s_{\alpha }^{\left(k\right)}$ represents language evaluation information, and $s_{1-k}^{\left(k\right)}$ and $s_{k-1}^{\left(k\right)}$ represent its lower limit and upper limit, respectively;

(3) Select the most frequently used language evaluation information set as the basic language, and use the conversion functions (2) and (3) to perform consistent conversion of other language evaluation information;

Let any two given continuous language scale sets be:

$$\begin{gathered} S^{\left(k_1\right)}=\left\{s_{\alpha }^{\left(k_1\right)}|\alpha \in \left[1-k_1,k_1-1\right]\right\} \\ {S}^{\left(k_2\right)}=\left\{s_{\beta }^{\left(k_2\right)}|\beta \in \left[1-k_2,k_2-1\right]\right\} \end{gathered}$$

Its conversion function is:

$$F:S^{\left(k_1\right)}\to s^{\left(k_2\right)},\beta =F\left(\alpha \right)=\alpha \frac{k_2-1}{k_1-1}$$

(2)

$$F^{-}:S^{\left(k_2\right)}\to s^{\left(k_1\right)},\alpha =F^{-}\left(\beta \right)=\beta \frac{k_1-1}{k_2-1}$$

(3)

After conversion, the decision matrix $R={(v_{il})}_{m\times t}$ with the same granularity can be obtained;

(4) Adopt the multi-objective mixed sorting method in TOPSIS theory. The positive and negative relative ideal points of the relative weight vector of this dimension evaluation index are recorded as $P^{+}$ and $N^{-}$ respectively, where:

Deterministic language variable:

$$P_i^{+}=\underset{l}{max}\left\{v_{ij}\right\}$$

(4)

$$N_i^{+}=\underset{l}{min}\left\{v_{ij}\right\}$$

(5)

Indeterminate language variable:

$$P_i^{+}=\left[P_i^{L+},P_i^{R+}\right]=\left[\underset{l}{max}\left\{v_{il}^L\right\},\underset{l}{max}\left\{v_{il}^R\right\}\right]$$

(6)

$$N_i^{-}=\left[N_i^{L-},N_i^{R-}\right]=\left[\underset{l}{min}\left\{v_{il}^L\right\},\underset{l}{min}\left\{v_{il}^R\right\}\right]$$

(7)

According to the algorithm of linguistic variables, let any two deterministic linguistic variables be $s_{\alpha }^{\left(k\right)}$, $s_{\beta }^{\left(k\right)}$, and any two uncertain linguistic variables be $s_1^{\left(k\right)}=\left[s_{{\alpha }_1}^{\left(k\right)},s_{{\beta }_1}^{\left(k\right)}\right]$, $s_2^{\left(k\right)}=\left[s_{{\alpha }_2}^{\left(k\right)},s_{{\beta }_2}^{\left(k\right)}\right]$, then the degree of separation $d$ between the two linguistic variables can be expressed as:

Deterministic linguistic variable:

$$d\left(s_{\alpha }^{\left(k\right)},s_{\beta }^{\left(k\right)}\right)=\frac{\left|\alpha -\beta \right|}{2k-1}$$

(8)

Uncertain linguistic variable:

$$d\left(s_1^{\left(k\right)},s_2^{\left(k\right)}\right)=\frac{\left|{\alpha }_1-{\alpha }_2\right|+\left|{\beta }_1-{\beta }_2\right|}{2\left(2k-1\right)}$$

(9)

Use Formulas (10) and (11) to calculate the distances $D_l^{+}$ and $D_l^{-}$ between the vector $v_j$ and the positive and negative relative ideal points $P^{+}$ and $N^{-}$, where ${\rho }_i$ is the weight of each evaluation expert:

$$D_l^{+}={\displaystyle \sum }_{i=1}^m{\rho }_{i}d\left(v_{il},P_i^{+}\right),l=1,2,\cdots ,t$$

(10)

$$D_l^{-}={\displaystyle \sum }_{i=1}^m{\rho }_{i}d\left(v_{il},N_i^{-}\right),l=1,2,\cdots ,t$$

(11)

(5) The relative weight of the evaluation index of this dimension can be described by the closeness coefficient $c_l$ between the vector $v_l$ and the positive and negative relative ideal points $P^{+}$ and $N^{-}$:

$$c_l=\frac{D_l^{-}}{D_l^{+}+D_l^{-}},l=1,2,\cdots ,t$$

(12)

By normalizing it, the relative weight $w_l^{\mathrm{II}}$ of the evaluation index of this dimension can be obtained:

$$w_l^{\mathrm{II}}=\frac{c_l}{{{\displaystyle \sum }}_{l=1}^t{c}_l}$$

(13)

By multiplying the above result with the weight of this dimension, the weight F(h) of the evaluation index of this dimension can be calculated [46]. By repeating the above steps, the weights of all evaluation indicators can be calculated.

$$F\left(h\right)=w_l^{\mathrm{II}}\times w_j^I$$

(14)

6. Empirical Research

This paper selected the coal supply chain in central China for empirical research. The supply chain is dominated by a state-owned coal enterprise in Shanxi Province. Coal production enterprises are the core of the supply chain, and also have auxiliary functions such as processing, storage, transportation and sales, and material management. Coal production is the main process, and only one transfer of coal ownership from the producer to the demander occurs in the entire supply chain. Upstream is the raw material, equipment, accessories, and other suppliers required for coal production. Downstream are coal demand enterprises. It is mainly based on the supply of physical goods and supplemented by the supply of value-added services. The supply chain is a mixed supply chain of manufacturing services, which consists of a front-end coal manufacturing supply chain (mainly coal production) and a back-end coal service supply chain (mainly coal circulation) [47]. The coal supply covers Shanxi Province, Beijing City, Tianjin City, and Hebei Province. The development goal of this supply chain is to cultivate new drivers of integration and innovation, build a new ecology of the modern supply chain, and demonstrate high-quality development and new operations. It has now become a leading commodity supply chain in China.

A total of five experts were invited to evaluate the sustainability of the coal supply chain. One is from a state-owned coal enterprise in the supply chain, and one is from a government management department. The remaining three are authoritative experts in supply chain management authorized and recognized by China Purchasing Federation. Through the summarization and calculation of the cognition level of each evaluation index by five experts, the weight of the sustainability evaluation index of the coal supply chain is scientifically and quantitatively determined by all parties. The specific index problems and the calculation process are as follows.

Taking the innovation dimension as an example, this dimension includes five evaluation indicators: attracting high-quality talents ($I_1$), R&D investment ($I_2$), intelligent management system ($I_3$), and complete localization of intellectual property rights ($I_4$), new product development cycle ($I_5$). Due to the differences in the cognition of the evaluation indicators by different evaluation experts, different forms of semantic granularity and linguistic variables were used to determine their weights. Three unbalanced semantic scale sets were used here, namely:

$$\begin{gathered} S^{\left(3\right)}=\left\{s_{-2}^{\left(3\right)},s_{-\frac{2}{3}}^{\left(3\right)},s_0^{\left(3\right)},s_{\frac{2}{3}}^{\left(3\right)},s_2^{\left(3\right)}\right\} \\ {S}^{\left(4\right)}=\left\{s_{-3}^{\left(4\right)},s_{-\frac{4}{3}}^{\left(4\right)},s_{-\frac{1}{2}}^{\left(4\right)},s_0^{\left(4\right)},s_{\frac{1}{2}}^{\left(4\right)},s_{\frac{4}{3}}^{\left(4\right)},s_3^{\left(4\right)}\right\} \\ {S}^{\left(5\right)}=\left\{s_{-4}^{\left(5\right)},s_{-2}^{\left(5\right)},s_{-1}^{\left(5\right)},s_{-\frac{2}{5}}^{\left(5\right)},s_0^{\left(5\right)},s_{\frac{2}{5}}^{\left(5\right)},s_1^{\left(5\right)},s_2^{\left(5\right)},s_4^{\left(5\right)}\right\} \end{gathered}$$

A multi-granularity language initial decision matrix $R^{\prime }={(v_{il})}_{m\times f}$, was built, as shown in

Table 3. Initial decision evaluation.

Expert	${\mathit{B}}_1$	${\mathit{B}}_2$	${\mathit{B}}_3$	${\mathit{B}}_4$	${\mathit{B}}_5$
Linguistic Variable Type	Certain	Uncertain	Uncertain	Certain	Certain
$I_1$	$S_2^{\left(3\right)}$	$\left[S_{\frac{1}{2}}^{\left(4\right)},S_3^{\left(4\right)}\right]$	$\left[S_2^{\left(5\right)},S_4^{\left(5\right)}\right]$	$S_{-\frac{4}{3}}^{\left(4\right)}$	$S_{\frac{4}{3}}^{\left(4\right)}$
$I_2$	$S_{\frac{2}{3}}^{\left(3\right)}$	$\left[S_{\frac{4}{3}}^{\left(4\right)},S_3^{\left(4\right)}\right]$	$\left[S_{-4}^{\left(5\right)},S_{-2}^{\left(5\right)}\right]$	$S_{\frac{1}{2}}^{\left(4\right)}$	$S_3^{\left(4\right)}$
$I_3$	$S_0^{\left(3\right)}$	$\left[S_0^{\left(4\right)},S_{\frac{1}{2}}^{\left(4\right)}\right]$	$\left[S_{\frac{2}{5}}^{\left(5\right)},S_1^{\left(5\right)}\right]$	$S_0^{\left(4\right)}$	$S_{\frac{1}{2}}^{\left(4\right)}$
$I_4$	$S_{-\frac{2}{3}}^{\left(3\right)}$	$\left[S_{-3}^{\left(4\right)},S_{-\frac{1}{2}}^{\left(4\right)}\right]$	$\left[S_0^{\left(5\right)},S_1^{\left(5\right)}\right]$	$S_3^{\left(4\right)}$	$S_0^{\left(4\right)}$
$I_5$	$S_{-2}^{\left(3\right)}$	$\left[S_{-\frac{4}{3}}^{\left(4\right)},S_0^{\left(4\right)}\right]$	$\left[S_{-1}^{\left(5\right)},S_0^{\left(5\right)}\right]$	$S_{-3}^{\left(4\right)}$	$S_{-\frac{4}{3}}^{\left(4\right)}$

:

Since three evaluation experts chose to take the unbalanced semantic scale set $S^{\left(4\right)}$, it was regarded as the basic unbalanced semantic scale set, and Formulas (2) and (3) were used to determine the initial decision matrix of multi-granularity language. $R^{\prime }$ was processed uniformly, and the language decision matrix $R={(v_{il})}_{m\times t}$ with the same granularity could be obtained, as shown in

Table 4. Consistent Decision Evaluation.

Expert	${\mathit{B}}_1$	${\mathit{B}}_2$	${\mathit{B}}_3$	${\mathit{B}}_4$	${\mathit{B}}_5$
Linguistic Variable Type	Certain	Uncertain	Uncertain	Certain	Certain
$I_1$	$S_3^{\left(4\right)}$	$\left[S_{\frac{1}{2}}^{\left(4\right)},S_3^{\left(4\right)}\right]$	$\left[S_{\frac{3}{2}}^{\left(4\right)},S_3^{\left(4\right)}\right]$	$S_{-\frac{4}{3}}^{\left(4\right)}$	$S_{\frac{4}{3}}^{\left(4\right)}$
$I_2$	$S_1^{\left(4\right)}$	$\left[S_{\frac{4}{3}}^{\left(4\right)},S_3^{\left(4\right)}\right]$	$\left[S_{-3}^{\left(4\right)},S_{-\frac{3}{2}}^{\left(4\right)}\right]$	$S_{\frac{1}{2}}^{\left(4\right)}$	$S_3^{\left(4\right)}$
$I_3$	$S_0^{\left(4\right)}$	$\left[S_0^{\left(4\right)},S_{\frac{1}{2}}^{\left(4\right)}\right]$	$\left[S_{\frac{3}{10}}^{\left(4\right)},S_{\frac{3}{4}}^{\left(4\right)}\right]$	$S_0^{\left(4\right)}$	$S_{\frac{1}{2}}^{\left(4\right)}$
$I_4$	$S_{-1}^{\left(4\right)}$	$\left[S_{-3}^{\left(4\right)},S_{-\frac{1}{2}}^{\left(4\right)}\right]$	$\left[S_0^{\left(4\right)},S_{\frac{3}{4}}^{\left(4\right)}\right]$	$S_3^{\left(4\right)}$	$S_0^{\left(4\right)}$
$I_5$	$S_{-3}^{\left(4\right)}$	$\left[S_{-\frac{4}{3}}^{\left(4\right)},S_0^{\left(4\right)}\right]$	$\left[S_{-\frac{3}{4}}^{\left(4\right)},S_0^{\left(4\right)}\right]$	$S_{-3}^{\left(4\right)}$	$S_{-\frac{4}{3}}^{\left(4\right)}$

.

Using Formulas (4)–(7), the positive and negative relative ideal points of the importance of the innovation dimension evaluation index could be calculated:

$$\begin{array}{l}{P}^{+}=\left\{S_3^{\left(4\right)},\left[S_{\frac{4}{3}}^{\left(4\right)},S_3^{\left(4\right)}\right],\left[S_{\frac{3}{2}}^{\left(4\right)},S_3^{\left(4\right)}\right],S_3^{\left(4\right)},S_3^{\left(4\right)}\right\}\\ N^{-}=\left\{S_{-3}^{\left(4\right)},\left[S_{-3}^{\left(4\right)},S_{-\frac{1}{2}}^{\left(4\right)}\right],\left[S_{-3}^{\left(4\right)},S_{-\frac{3}{2}}^{\left(4\right)}\right],S_{-3}^{\left(4\right)},S_{-\frac{4}{3}}^{\left(4\right)}\right\}\end{array}$$

Using Formulas (8) and (9), the degree of separation d was calculated, as shown in

Table 5. Calculation results of degree of separation.

Index		${\mathit{B}}_1$	${\mathit{B}}_2$	${\mathit{B}}_3$	${\mathit{B}}_4$	${\mathit{B}}_5$
$I_1$	+	0.0000	0.0595	0.0000	0.6190	0.2381
	−	0.8571	0.5000	0.6429	0.2381	0.3810
$I_2$	+	0.2857	0.0000	0.6429	0.3571	0.0000
	−	0.5714	0.5595	0.0000	0.5000	0.6190
$I_3$	+	0.4286	0.2738	0.2464	0.4286	0.3571
	−	0.4286	0.2857	0.3964	0.4286	0.2619
$I_4$	+	0.5714	0.5595	0.2679	0.0000	0.4286
	−	0.2857	0.0000	0.3750	0.8571	0.1905
$I_5$	+	0.8571	0.4048	0.3750	0.8571	0.6190
	−	0.0000	0.1548	0.2679	0.0000	0.0000

:

Five evaluation experts received their own weights through collective voting:

$$\rho =\left(0.20,0.15,0.10,0.25,0.3\right)$$

Using Formulas (10) and (11), the distance between the weight vector of the evaluation index and $P^{+}$ and $N^{-}$ was calculated:

$$\begin{gathered} D_l^{+}=\left\{0.2351,0.2107,0.3657,0.3536,0.6696\right\} \\ {D}_l^{-}=\left\{0.4845,0.5089,0.3539,0.3661,0.0500\right\} \end{gathered}$$

The closeness coefficient $c_l$ was calculated by Formula (12):

$$c_l=\left\{0.6733,0.7072,0.4918,0.5087,0.0695\right\}$$

By normalizing the Formula (13), the relative weight $w_l^{\mathrm{II}}$ of the evaluation index of the innovation dimension could be obtained:

$$w_l^{\mathrm{II}}=\left\{0.2748,0.2886,0.2007,0.2076,0.0284\right\}$$

Five evaluation experts obtained the weights $w_j^{\mathrm{II}}$ of the five dimensions of the first layer through collective voting:

$$w_j^{\mathit{II}}=(0.25,0.3,0.2,0.1,0.15)$$

The above result was multiplied by the weight of the first-layer innovation dimension, and the weight $F\left(h\right)$ of the evaluation index of the innovation dimension could be calculated:

$$F\left(h\right)=\left\{0.0824,0.0866,0.0602,0.0623,0.0085\right\}$$

By repeating the above steps, the weights of the evaluation indicators of the other four dimensions could be calculated respectively. The specific calculation results are shown in

Table 6. Evaluation index weights.

Economy		Innovation		Green		Coordination		Safety
Index	Weights	Index	Weights	Index	Weights	Index	Weights	Index	Weights
$E_1$	0.0456	$I_1$	0.0824	$G_1$	0.0413	$C_1$	0.0226	$S_1$	0.0448
$E_2$	0.0597	$I_2$	0.0866	$G_2$	0.0373	$C_2$	0.0024	$S_2$	0.0455
$E_3$	0.0741	$I_3$	0.0602	$G_3$	0.0480	$C_3$	0.0304	$S_3$	0.0157
$E_4$	0.0508	$I_4$	0.0623	$G_4$	0.0334	$C_4$	0.0168	$S_4$	0.0281
$E_5$	0.0198	$I_5$	0.0085	$G_5$	0.0400	$C_5$	0.0279	$S_5$	0.0158

:

After the results of the calculation were obtained, the index importance was revised. After a discussion by experts, the main factors affecting the importance of indexes were summarized into two points: highlighting the degree of domestic circulation and whether it was the core competitiveness. The new pattern of development of “dual circulation” is a major strategic deployment made by China based on the complex domestic and international situation. In the future, China’s economic development must be dominated by internal circulation, empowered by external circulation, and committed to achieving a higher level of dual circulation [48]. Core competitiveness is a unique competitive advantage that distinguishes it from other supply chains [49].

China’s coal supply chain sustainability evaluation index system from the perspective of “dual circulation” covers domestic and international aspects. Domestic indexes E1–E3, I1–I5, G1–G4, C1–C3 and S1–S4 are mainly based on the domestic market to highlight the domestic cycle. The international indexes E4–E5, G5, C4–C5 and S5 rely on the international market to reflect the opening level of China’s coal supply chain. Experts scored the competitive advantages highlighted by each evaluation index, with a full score of 10. Each expert scored each index as $a_i\left(i=1,2,3,4,5\right)$. After being scored by five experts, the final score of each indicator was $F\left(A\right)\left(A=E1,E2,\dots S5\right)$:

$$F\left(A\right)=a_i{\rho }_i$$

(15)

The average $B_i\left(\mathrm{i}=1,2,3,4,5\right)$ of the scores of the five experts was calculated, and multiplied by the weight of each expert as the demarcation point $O$ of the core competitiveness:

$$O=B_i{\rho }_i$$

(16)

After calculation, the cut-off point of core competitiveness was $O=6.27$. Therefore, the index with the final score greater than 6.27 was the core competitiveness index. Among the 25 secondary indicators, E3, E4, I1, I2, I4, G1, C3, C5, and S1 were the indexes selected after scoring that best reflected the core competitiveness of the coal supply chain. Starting with innovation, increasing investment in research and development, attracting high-quality talents, striving to localize intellectual property rights, and achieving upstream and downstream coordination through information sharing, ultimately achieving economic benefits while ensuring harmonious development with the environment. Finally, the above 25 secondary indicators were classified according to the degree of prominent domestic circulation and whether they were the core competitiveness, and different influence coefficients were assigned. The results are shown in Figure 3:

After calculation, the final evaluation indexes weights are shown in

Table 7. Weights of the revised evaluation indicators.

Economy		Innovation		Green		Coordination		Safety
Index	Weights	Index	Weights	Index	Weights	Index	Weights	Index	Weights
$E_1$	0.0416	$I_1$	0.0977	$G_1$	0.0490	$C_1$	0.0206	$S_1$	0.0531
$E_2$	0.0545	$I_2$	0.1027	$G_2$	0.0340	$C_2$	0.0022	$S_2$	0.0415
$E_3$	0.0879	$I_3$	0.0549	$G_3$	0.0438	$C_3$	0.0361	$S_3$	0.0143
$E_4$	0.0417	$I_4$	0.0739	$G_4$	0.0305	$C_4$	0.0153	$S_4$	0.0256
$E_5$	0.0126	$I_5$	0.0078	$G_5$	0.0255	$C_5$	0.0229	$S_5$	0.0101

:

7. Discussion

In this paper, the multi-granularity and unbalanced decision-making method is adopted to enable the weight of the evaluation index to be more accurate. In the evaluation process, each expert may have been limited by some influencing factors, such as different social experiences, professional knowledge, and cognitive level, which resulted in the evaluation of each expert being inconsistent with the semantic granularity. This method helps to overcome this problem. To further illustrate the effectiveness of the constructed evaluation index model and evaluation method, this paper used a coal supply chain in central China to conduct an empirical study, which provided a scientific and effective tool for the supply chain management of node enterprises. Its main functions were reflected in the following two aspects: (1) improving the efficiency of supply chain management, after obtaining accurate and reasonable indicator weights, focusing on improving indicators with higher weights under the condition of limited resources; (2) improving the level of supply chain management, making full use of the wisdom of various experts. Scientific research and judgment on the current situation of the enterprise provides a basis for the overall strategic goal of the enterprise, promotes the current “dual circulation” new development pattern in China, and achieves sustainable economic growth. After the evaluation results were obtained, this article was revised to bring the results in line with China’s requirement to pay more attention to smooth domestic circulation under the current epidemic situation.

According to the above model establishment and index calculation, the importance of the first-level indicators was: innovation > economy > green > safety > coordination. In the face of the global epidemic situation, supply chain innovation has become an essential measure of the new development concept, which plays a vital role in China’s domestic and foreign economic cycle. Experts also consider that the innovation dimension has a driving effect on other measurements. Through supply chain innovation, actively promoting green and low-carbon development of the industrial chain; through supply chain innovation, improving supply chain flexibility and toughness, strengthening supply chain risk control, ensuring supply chain security and stability; and through supply chain innovation, enterprises can form an operation mechanism with consistent goals and shared risks, and finally achieve the objective of high-quality economic growth.

The weight values of the second-layer indicators are shown in Figure 4, and the hands that need to be given priority in each dimension are shown in

Table 8. The priority action plan.

Index	Weight	Action
$I_1$	0.0977	Optimize policies for talent introduction and actively attract domestic and overseas professionals that are in short supply
$I_2$	0.1027	Increase investment in R&D investment and accelerate efforts to build an innovation ecosystem
$E_3$	0.0879	Highlight core competitiveness and focus on expanding domestic demand
$G_1$	0.0490	Accelerate breakthroughs in key technologies for clean and efficient utilization of coal and significantly reduce carbon emissions
$S_1$	0.0531	With the help of intelligence, establish a flexible coal supply system
$C_3$	0.0361	Build a coal supply chain information sharing platform

. The total weight of the innovation dimension was 0.3370, and the corresponding secondary indicators that must be prioritized are R&D investment and attracting high-precision talents, with consequences of 0.1027 and 0.0977, respectively. R&D investment is often associated with innovation effectiveness. R&D investment is the driving force and source of innovation, and talent is the first resource of supply chain innovation. When constructing the sustainable coal supply chain of China from the perspective of “double circulation”, we should consider the cultivation and introduction of professionals and technological innovation as breakthroughs to improve the innovation management level of the supply chain. The total weight of the economic dimension was 0.2383, and the corresponding secondary indicator that needs to be prioritized is sustainable development capability, with a weight of 0.0879. The long-term development situation is the foundation for the survival of coal enterprises. The epidemic situation is still difficult, and coal demand fluctuates wildly. It is essential for the current development to tap into the potential of the domestic market, integrate the sustainable development ability of the supply chain into strategic operation and management, and enhance the development potential of China’s domestic coal economic operation. The total weight of the green dimension was 0.1828. The corresponding secondary indicators that need to be prioritized are primary air pollutant emissions and carbon emissions levels, with a weight of 0.0490. It is China’s significant decision-making and deployment plan to take a green and low-carbon development path in response to global climate change. It achieves the goal of green and sustainable development while reducing environmental pollution. Enterprises should pay attention to the quality of ecological protection of relevant subjects in the domestic coal supply chain and pursue the double harvest of economic and green interests. The total weight of the safety dimension was 0.1447, and the corresponding secondary indicator that needs to be prioritized was coal supply stability, with a weight of 0.0531. Coal supply is an important indicator to work on, to avoid supply chain interruption. When selecting coal supply, enterprises with strong core competitiveness should be considered to join in, to realize complementary advantages and create a safe supply chain sharing profits and risks. The total weight of the coordination dimension was 0.0971. The corresponding secondary indicator that needs to be prioritized is the degree of upstream and downstream information connectivity, with a weight of 0.0361. Upstream and downstream node enterprises should strengthen information exchange, realize information sharing, innovate a new coordinated development mode of coal supply chain management, pay more attention to information authenticity in the context of the epidemic situation, and avoid the “bullwhip effect”.

Based on the above results, this paper makes the following policy recommendations:

First, in terms of innovation, relevant entities in the coal supply chain should thoroughly implement the innovation-driven development strategy, continue to expand investment in scientific research, and accelerate the construction of an innovation ecosystem between upstream and downstream links in the coal supply chain. An open and effective talent policy will create a highland for scientific research and innovation talents in the coal industry. Only by achieving the effective combination of approaches, funds, and skills can we continuously promote independent ownership of the core technologies of China’s coal industry and constantly release the vitality of the coal industry.

Second, as far as the economic dimension is concerned, the sustainable development capability should be regarded as the first goal by relevant entities in the upstream and downstream of the coal supply chain. Relying on core technological innovation and product development with the coexistence of high technology content and high added value, the overall profitability will be continuously expanded. At the same time, based on the dual-cycle development pattern, it is necessary to ensure the forward-looking development of the coal industry, study and judge the demand trend under the “dual market”, effectively integrate resources, and achieve high-quality economic growth.

Third, as far as the green dimension is concerned, it is necessary to thoroughly understand the construction requirements of the “14th Five-Year Plan”, so that relevant entities in the coal supply chain can establish a development strategy focusing on carbon reduction and promoting synergistic efficiency of pollution reduction and carbon reduction [50]. The green development requirements are actively in line with international green standards, so that the green development of the coal industry can increase efficiency and feedback to high-quality economic promotion.

Fourth, in terms of security, it is imperative to efficiently integrate domestic coal stocks, open international coal import channels, and ensure coal energy security. At the same time, it is important to strengthen the maintenance of safety technology systems and the protection of the facilities in all aspects of the coal supply chain to provide a safe operating environment within the coal supply chain.

Fifth, as far as the coordination dimension is concerned, it is particularly crucial to integrate domestic and foreign market information. Based on this, China should establish an in-depth layout of the construction of new infrastructure that provides services such as digital transformation and intelligent upgrading, and relevant entities in the coal supply chain should improve their ability to use the country’s cutting-edge information technology, based on dual markets, extend information sources, and enhance the quality of information acquisition. While ensuring the efficient and coordinated development of relevant entities, we will continue to improve the ability to utilize international market resources.

Based on the above analysis, when building a coal supply chain, we should actively integrate all forces to establish a coal supply chain with integrated production, transportation and demand, smooth information and materials, and agile response, to achieve sustainable and stable development.

8. Conclusions

Based on the perspective of the new development pattern of “dual circulation”, this paper studied the sustainable evaluation of the coal supply chain, and specifically:

(1) Proposed a five-dimensional “economy-innovation-green-coordination-safety” performance evaluation index system, covering both domestic and international aspects, which specifically included five first-level indicators and twenty-five second-level indicators;

(2) A sustainable evaluation index system model of the coal supply chain was constructed, which adopted multi-granularity unbalanced decision-making and TOPSIS theory. The combined method made use of multi-agent cognitive differences to evaluate the target comprehensively, scientifically and effectively;

(3) Based on the above, an empirical study was carried out, taking the coal supply chain in central China as an example, which verified the scientific effectiveness of the method. The research results of this paper will provide effective theoretical support and a decision-making basis for the sustainable development of coal supply under the new development pattern of “dual circulation”, and offer new ideas for the development of China’s energy industry in the new era, integrating with global standards, and reshaping international core competitiveness.