1. Introduction
Agricultural green supply chain management (AGSCM) aims to transform environmental constraints into advantages and opportunities, such as eco-brand, green consumption, and sustainable development, which is difficult to optimize influenced by complex and interactive factors intrinsic in an ever-changing complex environment, which includes global warming, the COVID-19 pandemic, and environmental pollution. In particular, agriculture is one of the largest sources of methane emissions, with the Food and Agriculture Organization (FAO) stating that the emission of greenhouse gas will increase by 30% by 2050 [
1]. With the increasing concern for green and sustainable development, more and more consumers are forcing the traditional supply chain reform to become environmentally conscious with components, such as biological pesticides, renewable energy, recyclable packaging, environmentally friendly fertilizers, and so on [
1,
2].
As we know, the yield of agricultural products is particularly influenced by many uncertain challenges related to environmental, political, economic, social, technical, and legal dimensions, which has become a major issue affecting human beings in recent years [
3]. A growing global population and a deteriorating environment have led to an increased focus on agricultural supply chains, such as resource constraints and environmental pollution [
4]. With the growing environmental awareness, decision makers must take environmental factors into account in supply chain management. The implementation of environmental and social performance expands the scope of legal, social, technical, economic, and ethical properties in green supply chain management (GSCM) [
5]. Furthermore, the performance of GSCM combines environmental, social, and economic dimensions, which must be considered in many interrelated operations, such as planning, production, packaging, transportation, storage, processing, distributing, publicity, and sales [
6,
7,
8]. Sustainability has become a necessary obligation for enterprise development. Enterprises need to take responsibility for social and environmental issues in supply chain management [
9]. However, AGSCM has become more difficult with the spread of the COVID-19 pandemic, global warming, extreme climate, and environmental pollution across the world.
Although there have been a few attempts to study agricultural green supply chain management [
10,
11,
12], these studies mainly studied the factors which are independent of each other as a prerequisite assumption but ignored the interrelationships within them. This assumption may limit the development of AGSCM and the improvement of economics. However, there are many uncertain complex hierarchical factors affecting AGSCM, such as perishability, seasonality, customers’ demand, and supply relationships [
13]. In order to improve development of AGSCM within the restrictions of available natural resources, the decision support model must be concentrated on the real-world scenario and integrated with complicated methods to evaluate performance and the relationship of every factor [
14].
Multiple-Criteria Decision-Making (MCDM) methods are designed to address complex decision-making difficulties by analyzing the structure of criteria, alternatives, and decision-makers’ preference, which are suitable for assisting managers, practitioners, and developers in selecting the best options within various conflicting criteria. Saaty introduced the Analytic Hierarchy Process (AHP) as a popular MCDM approach in 1980. The hierarchical structure of AHP makes it possible to visualize the factors influencing the alternatives. Analytic Network Process (ANP) is an amplification of AHP which can take into account the intricate interdependence of decision factors in a hierarchical structure [
15]. To deal with the uncertain situation, the fuzzy AHP and ANP have been used in many domains [
16,
17]. So, the hybrid MCDM methods have the advantage to accomplish analysis the imprecise, incomplete, or uncertain information.
In contrast to the methods mentioned above, the Decision-Making Trial and Evaluation Laboratory (DEMATEL) is an advanced and sophisticated decision-making method for addressing interdependencies by visualizing the causal interactions of indicators proposed by Gabus and Fontela [
18]. DEMATEL uses mathematical tools to comprehend various specialists’ perspectives on associated factors, as well as logical correlations and direct effects between these factors [
19], which has been widely used in supply chain management (SCM) [
20,
21,
22]. Michnik developed the Weighted Influence Nonlinear Gauge System (WINGS) approach from DEMATEL [
23]. With interdependencies of factors in MCDM situations, DEMATEL simulates the direction and strength of the impact. Furthermore, WINGS simulates both the intensity and direction of the influence, in addition to the strength of the criterion, which could be utilized as a theoretical basis for AGSCM. However, classical DEMATEL and WINGS methods ignore the vagueness and uncertainty of human judgment that are so prevalent in real life. Regarding this problem, the Grey theory may successfully handle the ambiguities inherent in human subjective judgement while acquiring accurate results with a moderate data sample.
The contribution of this paper can be summarized as follows.
A fuzzy-Delphi and grey-WINGS approach to decision theory, which can be utilized to analyze different group choices, ambiguity, and complex interrelationships in evaluation problems, is presented in this study. The combination of a fuzzy set and grey theory can provide a more realistic representation of human judgement under ambiguous and subjective conditions.
The target of this study is conducive to the improvement of AGSCM by applying the current assessment approach to provide a more accurate and objective prioritization tool for AGSCM in a hazy and diverse environment. The approach is intended to assist AGSCM designers in identifying the most critical factors with the highest potential.
The fuzzy-Delphi and grey-WINGS method integrates four techniques, which have not been combined for illustrating mutual relationships of factors in previous studies. According to the results analysis, this research contributes significantly to improving AGSCM by providing policy and management implications.
3. Materials and Methods
The proposed model combining fuzzy Delphi and Grey WINGS contains two phases as in
Figure 1. Firstly, identifying and finalizing the factors of AGSCM. Secondly, a cause-and-effect analysis of the components that have been selected will demonstrate how they interact.
3.1. Influencing Factors of AGSCM
Based on the status of the AGSCM and structural analysis approaches that have been applied to supply chain management, an evaluation method of the influencing elements of AGSCM has been constructed. We chose 19 factors from three dimensions including government, economy, and society, including green consciousness, competitive pressure, government subsidies, produce quality, customer demand, environmental laws, logistics, renewable material, green operation, technology, waste reduction, price of product, cost, stockholders’ requirement, monitoring, social responsibilities, infrastructure, income level, and reusable packaging.
3.2. Fuzzy Delphi
The theory of fuzzy sets proposed by Zadeh to describe the ambiguity of human cognitive processes formed the basis of the fuzzy-Delphi technique. A triangular fuzzy number can be presented like
, where
. Then, the membership function is:
The basic operations show as:
where
The following are all fuzzy-Delphi steps:
Step 1: This process involves identifying and categorizing numerous factors that are relevant to the field under research.
Step 2: Once the criteria have been established, the experts are given the questionnaire detailing the criteria to compare by using the linguistic scale listed in
Table 3. Fuzzy numbers could be transformed from experts’ evaluations for each criterion. A fuzzy number referring to the
cth factor suggested by the
ath expert is expressed as:
where
p and
q are the number of criteria and experts.
The fuzzy number for each criterion could be estimated using triangular fuzzy numbers (
E), as stated in Equation (4), which integrates the evaluations from all
q experts as follows:
Step 3: The fuzzy number of each assessment factor should be defuzzied using the Simple Center of Gravity (SCGM) approach to obtain the final value of each factor, which is the most prevalent approach for defuzzification [
73]. This stage of SCGM involves computing the defuzzification value
G using the mean approach as shown below:
Step 4: A threshold value (β) must be defined to choose the most significant criteria from the expert group in order to create the list of criteria. The final step is to construct the final list of criteria based on the following threshold criteria: The criterion is chosen if G ≥ β, and the criterion is omitted if G ≤ β.
3.3. Fuzzy-Delphi Grey-WINGS Model
The main steps can be described as:
Step 1. Determine selection criteria by using the fuzzy-Delphi method.
Numerous factors relevant to AGSCM are estimated by experts. After gathering expert opinions from surveys, the triangle fuzzy numbers are utilized to determine selection criteria through the Delphi method.
Step 2. Construct an initial strength–influence matrix for all experts.
Table 4 displays the language evaluation and the related grey numbers, which could measure factor x impact over factor y using an integer scale ranging from 0 to 4, indicating “no influence”, “low influence”, “medium influence”, “high influence”, and “very high influence” between factors.
Step 3. Compute the corresponding grey matrix for the strength–influence matrix.
The ratings on the integer scale can be transformed into corresponding grey scales that give an upper range and a lower range of values. Based on the obtained grey values, the initial relation matrices are transformed into grey relation matrices, as , where x,y indicate the criterion, and a indicates the ath expert, 1 ≤ a ≤ q; 1 ≤ x ≤ p; 1 ≤ y ≤ p.
Step 4. Calculate the average grey strength–influence matrix.
The average grey strength–influence matrix
can be computed by
q grey relation matrices,
Step 5. Obtain the crisp strength–influence matrix.
(1) Standardization of the grey number:
(2) Normalization of the crisp values:
(3) Calculate the accurate total crisp values.
and
Step 6. Obtain the normalized strength–influence matrix.
The element of matrix is between 0 and 1.
Step 7. Acquire the total strength–influence matrix.
The matrix
is obtained by:
where
, and
I presents an identity matrix.
Step 8. Sum of rows and columns in matrix Z.
The sum of rows (
T) and columns (
L) in matrix
Z can be calculated as:
T depicts the whole influence of component c as a cause affecting remaining components, while L illustrates an effect as the whole influence from other components impacting component a.
Step 9. Set up cause–effect relationship diagram.
Using the values obtained through Equations (13) and (14), a causal diagram is set up. The total impacts the given and received values by factor x, which represents the degree of prominence in the overall system.
The sum (T + L) presents the total effects by factor x, which represents the degree of prominence in the overall system, while (T − L) illustrates the net effect of factor x on the overall system. Factor x is the net cause if (T − L) is positive. Then, factor x is the net effect if (T − L) is negative.
Step 10. As shown below, a threshold value (
β) is established to eliminate minor effects.
where
N is the number of factors in matrix
Z.
5. Discussion
In most cases, we encounter complex MCDM problems in which the factors are mutually influenced by each other. Due to the dependencies between various factors, it is not true that any one factor can improve the entire system. Therefore, it is necessary to identify the interrelationship of the factors in the causal group that can be improved and thus influence the entire system. Considering the above situation, this study proposes a novel combination of fuzzy-Delphi and grey-WINGS techniques to illustrate the causal relationships among the factors of AGSCM. To select the relatively more important factors, a threshold of 0.6 was set in the fuzzy-Delphi method. Furthermore, utilizing the integrated grey WINGS approach, the causal relationships between the factors can be identified by aggregating the group subjective assessment from various decisionmakers. As a result, the integrated fuzzy-DELPHI grey-WINGS methods can make a significant contribution to the MCDM employed in the AGSCM.
Based on the values of (T + L) in
Table 12, the factors are prioritized as F9 > F5 > F2 > F4 > F12 > F7 > F6 > F8 > F1 > F11 > F3 > F10. Moreover, the ranking of cause–effect relationships is based on (T − L) values. Qualitative and prioritized ranking of the factors in the causal group helps to identify about how much influence each factor has. Based on positive and negative signs, the factors can be categorized into two parts as causal and effect factors in
Table 12. The causal factors can be sorted as F3 > F8 > F1 > F5 > F10 > F7, and the ranking of effect factors is obtained as F11 > F12 > F4 > F2 > F9 > F6. Through
Table 12 and
Figure 3, produce Quality (F3) was found to be the prime causal factor with a value of 0.0641. Price of product (F8) and green consciousness (F1) followed the primary factor with values 0.0577 and 0.0447. The environmental laws (F5), stockholders’ requirement (F10), and technology (F7), also can be categorized as driver factors, since the values are 0.0309, 0.0154, and 0.0048, which are greater than 0. These factors’ impacts are higher than other factors, such as monitoring (F11), income level (F12), customers’ demand (F4), government subsidies (F2), cost (F9), and green operation (F6). In order to demonstrate the advantage of this model, the result of DEMATEL was calculated to compare with WINGS, which is derived from DEMATEL. As shown in
Table 14, most causal and effect factors are the same except for F10, which is the same factor with min T + L value between the two methods. Furthermore, F11, F7, F1, F12, F2, and F5 have a similar sequence to T + L values, but the other factors are different in both methods. The discrepancy is caused by the assumption that the WINGS considers the strength of the indicator itself, while DEMATEL omits these ingredients, which lacks a certain degree of accuracy.
Further analysis should be performed by categorizing all the factors into various quadrants, with factors above the X-axis being prominent as causal factors, and factors below the X-axis being effectors due to their dependence on causal factors. As illustrated in
Figure 2, all the factors can be classified into four distinct clusters, where quadrant 1 is the least relevant factor or the least important factor. Monitoring (F11) lies in this group. Quadrant 2 is the causal group of factors that have a driving effect on other factors, but a weaker driving effect. Stockholders’ requirement (F10) and product quality (F3) belong to this area. The shareholders generally set the goals of corporate development based on their requirements, which in turn influence various activities, including production, sales, and management operations. The next quadrant 3 is the most important and critical factor in the causal group. Green consciousness (F1), product price (F8), environmental law (F5), and technology (F7) belong to this group, thus indicating their importance to AGSCM. As discussed above, these factors have a high degree of prominence and relationship, which are priorities in AGSCM, since they can dominate other influencing factors. The fourth quadrant is for factors of high importance in the effect group, which require immediate management attention and control to improve AGSCM. Green operations (F6), cost (F9), government subsidies (F2), customer demand (F4), and income level (F12) are in this area, which integrates the activities of various parties, such as government, consumers, and companies for improving the development of AGSCM.
6. Conclusions
This study concentrates on the hierarchical evaluation structure in a complete model and proposes a novel approach using fuzzy Delphi and grey WINGS to resolve the interrelationships and incomplete information to acquire the strength and relationship between the factors of AGSCM. The practical implications and insightful conclusions of this study can be explained as follows:
With the globalization of climate change, food crisis, and the issue of the vulnerability of the agricultural supply chain, AGSCM is a complex MCDM project, which requires high priority by any organizations that are facing competition and pressure from enterprises, society, and governments. Therefore, the AGSCM needs to be improved through the optimization of influencing factors. To meet the requirements of green development, managers and policy makers strike a balance between efficiency and redundancy in the AGSCM. It is very important for the top managers to actively focus on the critical factors.
In this paper, identifying the critical factors and the corresponding causal relationships in AGSCM is the purpose. These findings suggest some preliminary guidance for the successful implementation of AGSCM. In this paper, the novel integrated method utilizes a structural modeling tool based on fuzzy Delphi and grey WINGS to evaluate the various factors of AGSCM. The fuzzy-Delphi technique is a qualitative approach for gathering opinions from various participants, which can capture the ambiguity and uncertainty in the data. By combining grey systems theory with this method, it is quite practical for integrating the preferences and views of different experts. Through the causal diagram, the factors can be divided into cause-and-effect groups. From a research perspective, this approach is valuable for assessing the relative impact and strength of the various relationships in MCDM.
The implementation of the proposed model illustrates some perspectives on the actual application and management implications of AGSCM. Some fundamental factors have been found to adjust plan and solutions. Furthermore, the cause-and-effect relationships can help to identify the factors that practitioners and researchers need to consider in AGSCM.
Product quality (F3), price of product (F8), green consciousness (F1), and environmental law (F5) are the most vulnerable causal factors of AGSCM, which need more attention. Product price (F8) and quality (F3) are the eternal concerns of consumers. Product quality (F3) is one of the main tools for marketers to position themselves in the market, which has two components: level and consistency. Agricultural product quality means the ability of an agricultural product to perform its function, including its nutrition, taste, safety, and other attributes. Price of product (F8) is the basis for establishing a diversified market mechanism, designing an efficient incentive mechanism and playing an important role in positive incentive effect, which is related to the whole process of production and marketing. Reducing the cost of green agricultural products can improve the operation of AGSCM. Environmental laws (F5) and green consciousness (F1) are the important factors for improvement of AGSCM, which refer to the activities to reduce and minimize environmental pollution of various factors. Furthermore, green consciousness (F1) improves the social image and environmental performance with new life cycle assessment, which would influence stockholders’ perceptions. Environmental laws (F5) can guide agricultural production operators to scientific planting, breeding, application of pesticides, fertilizers, and other agricultural inputs. Moreover, the agricultural nonpoint pollution and other agricultural waste can also be reduced, so that AGSCM performance could be greatly developed.
Consumer demand (F4) is the number of items which consumers are able and willing to buy with any given price. The former is influenced by the level of demand for the good, the price of the good, and the price of the substitute good, while the latter is influenced by the consumer’s willingness to buy and the actual income level. Thus, it can be stated that the price of the agricultural product determines the quantity of consumer demand. Stockholders’ requirements (F10) are directly associated with activities of green product and process in AGSCM, as well as require incorporating green innovation for modifying product green operation, cost control, and satisfying customers’ demand.
Cost(F9) is the economic value of the resources consumed to produce and sell a certain type and quantity of products measured in money. The cost of agricultural products is influenced by a variety of factors, which require focusing on. Moreover, technology (F7) is an important support to improve agricultural production capacity and competitiveness. Agricultural technology is an irreplaceable and important guarantee for the promotion of supply chain management, which is an important support to promote the development of the agricultural economy. It is necessary to strengthen government support for agricultural technology promotion, deepen the reform of the agricultural technology promotion mechanism, innovate in the agricultural technology promotion organization, and form a socialized agricultural technology service system, which is necessary to adapt to the development of AGSCM.
Government subsidies (F2) can improve the efficiency of the entire green agricultural production, thus promoting the motivation of agricultural supply chain participants to utilize green technology and supply green agricultural products. Moreover, since government subsidies can compensate some costs of green product producers, these producers can offer green products at lower prices. For the whole society, government subsidies for green agricultural products improve the willingness of consumers to pay for green consumption and increase the consumer surplus that consumers can obtain by consuming green agricultural products. Monitoring (F11) refers to the management of political, economic, and social public affairs by the relevant departments, which can supervise and manage the behavior of the subjects at all levels in the green agricultural supply chain through laws and regulations. Monitoring is not only conducive to maintaining fair development rules, but also can create a harmonious and stable social environment, thus making the green supply chain develop in a better and healthier way.
In summary, all participants of AGSCM can analyze each influencing factor and its supporting causes, or they can identify the causal links of each influencing factor through a cause–effect diagram. This can help them identify and categorize those factors and their relationships that need more attention.
This paper has some limitations. Firstly, though a sizable number of specialists took part in the investigation, there might still be some bias in the experts’ assessments, and more experts can be invited to verify the statistical results of this study. Secondly, we have considered 19 factors of AGSCM, and more factors can be added at the expense of complexity. From this study, future studies could use other MCDM approaches, such as DEMATEL and ANP, and results can be compared to check the accuracy of grey WINGS. Furthermore, this proposed method could be extended to other MCDM problems in different industries, such as healthcare, the environment, pollution, transportation, etc.