# Operation Optimization of Supply Chain Financial System Based on System Dynamics

Authors: YiTian Hong
Journal: Computational Intelligence and Neuroscience
 (2022)

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## Abstract

Supply chain finance solves the problem of financing difficulties for small- and medium-sized enterprises, reduces the risk of financial services of financial institutions, and brings new profit growth points to logistics enterprises. Therefore, supply chain financing has achieved rapid growth in a short period of time in China. This paper aims to study how to analyze and study the collaborative development of supply chain finance based on system dynamics. This paper puts forward the problem of system operation optimization, which is based on system dynamics, then elaborates on the concepts of SD and SCF, and designs and analyzes a case of a supply chain financial system based on system dynamics. The experimental results show that increasing the “bank input” from 0.1 to 2 can bring considerable economic benefits in the long run. As far as the simulation results are concerned, the promotion effect on the supply chain is the most significant. The output value of the supply chain can be increased from 2,963.04 billion yuan to 4,211.73 billion yuan, an increase of 42.14%. The simulation results showed that the financial industry has a significant positive effect on the factor of supply chain support, which provides evidence support for further guiding practice.


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## Body

## 1. Introduction

With the development of globalization, the Internet, and supply chain information, the main role of Internet-based supply chain financing is not only to innovate financial instruments but also to develop and improve the financial market environment to better promote the development of the industry and solve the problems of financing difficulties for small- and medium-sized enterprises or difficulties in the industrialization of small- and medium-sized enterprises.Based on the theory of system dynamics, this paper describes the internal structure and operation of the supply chain financial system [1–3]. From the perspective of system dynamics, the operation process of different financing methods in the supply chain is described, and the sensitivity of model elements is deeply examined. The established system dynamics model examines the relationship between different elements in the system in detail, and the analysis is more comprehensive.The innovations of this paper are as follows: (1) This paper combines system dynamics and supply chain finance and introduces the theories and related methods of the two in detail. The BP neural network is also briefly described. (2) In the face of the collaborative optimization of the supply chain financial system based on SD, the process of the financing warehouse model, the SD flow diagram of the financing warehouse model, and the process of the accounts receivable model are analyzed and studied, respectively. By evaluating the experimental results and comparing the simulation results obtained from different “bank inputs,” it is concluded that the financial industry, including the bank input, will increase the support for the logistics industry and increase the degree of dependence between the two. A win-win situation for investors, recipients, and the entire macroeconomy can be achieved in the long run.


## 2. Related Work

The close integration of supply chain finance with real industries and finance has greatly promoted the continuous development of supply chain entities, especially small- and medium-sized enterprises. Taking JD.com as an example, Ding analyzed the framework of the supply chain finance operation mode of e-commerce enterprises. With the advantages of the Internet, e-commerce supply chain finance can more efficiently integrate logistics, information flow, and capital flow, thereby expanding the scope of participants in economic activities. He put forward relevant countermeasures and suggestions through the analysis of JD’s supply chain finance business model and its development characteristics. However, his research is one-sided [4]. Zheng analyzed the coordination mechanism of B2C cross-border e-commerce supply chain finance (SCF) and found that supply chain finance can reduce the interest rate of commercial banks, increase accounts receivable, greatly increase the credit line of commercial banks, and finally solve the financing problem of nonbasic enterprises and upstream small and medium manufacturers. Research has found that reputation mechanisms can increase the chances of fulfilling a contract, thereby addressing the problem of breach of contract. However, his process is more complicated [5]. Ali aims to find out the relationship and degree of governance of the determinants of scale to supply chain finance. His research shows that size determinants have a positive but modest effect on SCF, while WC directly dominates because WC contains components of CCC. However, he did not give relative countermeasures [6]. Wei developed various collusive and noncollusion game models for different supply chain finance (SCF) transaction structures and studied the impact of SCF transaction structures on the collusive boundary conditions. Finally, he summarizes the theoretical significance and analyzes the management significance through a case study. However, he is not based on reality [7]. Shaik examines the impact of supply chain finance (SCF) on company financial performance in Saudi Arabia’s materials sector as measured by return on assets (ROA), Tobin’s Q, and gross operating profit (GOP). The findings are helpful for academicians and managers of materials, inventory, sales departments, and supply chain managers to integrate financial and SCM for business benefits. However, he did not give specific data to prove [8]. A great way for Karim A S to take a fresh perspective is to examine how leading consumer business (CB) organizations are effectively transporting goods through their supply chains. His research aimed to determine the impact of the financial supply chain on money laundering intentions in the Indonesian banking sector, and his design combined quantitative and qualitative methods. The results show that the financial supply chain system has a positive impact on money laundering intentions. However, its scope of application is limited [9]. Jin and Wang examined the role of factoring in bilateral supply chains, where both suppliers and retailers are financially constrained. Their analysis shows that supplier funding shortages limit the advantages of trade credit to retailers. To overcome this limitation, they devised a hybrid strategy consisting of trade credit and factoring and then looked at how suppliers could use factoring strategies to achieve optimal performance. However, its performance could not be further broken [10]. Starting from the basic concepts and characteristics of supply chain financing, Xiaoyi-Li compared and analyzed the financing advantages, operational advantages, and competitive advantages of supply chain financing. Finally, he discussed the possible financial advantages of SMEs based on supply chain financing and provided new ideas for solving the financing difficulties of SMEs. However, his research depth is not enough [11].


## 3. The Coordinated Development Method of Supply Chain Finance

### 3.1. Supply Chain Finance

#### 3.1.1. Overview

The concept of supply chain finance (SCF) was first proposed in the field of logistics finance. It refers to a financial financing service provided for upstream and downstream small- and medium-sized enterprises in a specific supply chain of an industry [12–14]. Through the joint cooperation of financial capital and the real economy, it improves resource utilization, reduces inventory, reduces financing costs, and jointly creates a benign economic ecology in which financial institutions, real enterprises, and logistics enterprises coexist and benefit from each other. Supply chain collaboration refers to the mutual cooperation and coordination and resource efficiency of each node enterprise in the supply chain in order to improve the overall competitiveness of logistics. The existence of win-win consciousness makes supply chain enterprises rely on mutual trust, mutual commitment, and flexible negotiation and realize cooperative supply chain management [15]. Figure 1 shows the supply chain financing model.Figure 1
Supply chain finance model.To study the coordination of the supply chain financial system, we must first analyze the objects coordinated with the supply chain financial system. A comprehensive analysis of the supply chain financial system is the basis of supply chain collaboration research. The internal elements of the supply chain financial system mainly include financial institutions, outsourcing enterprises, key enterprises in the supply chain, and small- and medium-sized enterprises. Different cooperative relationships among the main players in the system form different types of financial supply chain system structures. The main function of supply chain financing, as an innovative financing model, is to provide intermediate services such as fund settlement [16, 17].


#### 3.1.2. Structural Analysis of the Supply Chain Financial System

(1) The Structure of the Supply Chain Financial System under the Principal-Agent Mode. When small- and medium-sized enterprises in the supply chain are short of funds, under the traditional model, enterprises generally ask banks for financing needs and obtain loan services. However, based on the financing model under the traditional model, because the SMEs have less collateral and pledged assets, banks are worried that the risk is too great and may not provide financing services to SMEs. Since the logistics company participates in the entire transaction process of the supply chain, it has a deep understanding of the specific operation of the affiliated companies in the supply chain [18]. Therefore, if they can get the support of the logistics company, the bank can not only obtain financing but also monitor the actual operation status and effectively supervise the goods mortgaged by the enterprise when making loans, which can significantly reduce the risk of bank loans to a certain extent. The borrower business can also obtain financing in the corresponding amount.In this model, the role of the logistics company can be defined as the “principal-agent role.” At present, the logistics company only acts as a representative of the bank to supervise the basic operating conditions and commitments of the borrower’s business according to the needs of the bank and provide corresponding emergency response mechanisms when necessary. The motivation of the logistics company as the lead agent mainly comes from two aspects: one is the motivation to become a supply chain agent; the other is the supervision and consulting fees provided by financial institutions such as banks; the specific structure is shown in Figure2(a).Figure 2
Structure diagram of the supply chain financial system with different models. (a) Structural diagram of the supply chain financial system under the principal-agent mode. (b) Structural diagram of the supply chain financial system under the unified credit model. (c) Structural diagram of the supply chain financial system without the participation of logistics enterprises.
(a)(b)(c)(2) The Structure of the Supply Chain Financial System under the Unified Credit Mode. In the principal-agent mode, the moral hazard caused by information asymmetry is the key issue for banks to consider when financing, so banks have to take incentives and necessary restraint mechanisms for logistics enterprises, and these measures will inevitably lead to costs. Financial institutions have taken this into consideration, and on the basis of weighing costs and benefits and on the basis of simplifying operating procedures and reducing the human and material resources of financial institutions themselves, they have launched a supply chain financial system under a unified credit model [19].The supply chain financial system under the unified credit model means that the bank directly grants a fixed amount of loan to a logistics enterprise with a certain scale and good reputation. Under this model, the bank basically does not need to contact the borrowing company, the logistics company decides who and how much to lend, and the bank only needs to charge the logistics company for a preagreed capital gain. So this greatly reduces the operational process of the bank. On the other hand, because the unified credit model gives logistics enterprises a lot of autonomy, it can greatly stimulate the enthusiasm of logistics enterprises to carry out business and improve the efficiency of logistics operations, so it has also been developed to a certain extent in practice. The specific system structure diagram is shown in Figure2(b).(3) The Structure of the Supply Chain Financial System without the Participation of Logistics Enterprises. A supply chain financial system without the participation of logistics enterprises means that financial institutions control the actual background of supply chain transactions in the entire financing process according to their own wishes. This financing model is generally suitable for situations where the financing process is relatively simple, and the financial institution has a clearer understanding of the financing companies and the core companies in the supply chain. Due to the long-term strategic cooperative relationship between enterprises, banks can obtain real and effective information on the capital status of the entire supply chain and the operation status of enterprises without the help of third-party enterprises. Therefore, based on this situation, financial institutions do not have to introduce third-party logistics companies to increase financing costs, and because of the reduction of participants, the entire financial system becomes simpler [20, 21]. The specific structure diagram is shown in Figure 2(c).


#### 3.1.3. Collaborative Management of Supply Chain Financial Systems

The concept of synergy first appeared in physical research, which originally refers to the combination of a variety of organizational individuals to form a whole and play a greater role and value than the sum of the individuals.The collaborative management of supply chain finance is proposed based on the concept of collaboration as a systematic discipline spanning natural sciences and social sciences, and the theory of collaborative management of supply chain finance studies the characteristics of regular changes among enterprises in the supply chain financial system. It is also recognized that there is an interactive and inseparable relationship between enterprises. Therefore, when supply chain finance based on system dynamics applies collaborative management theory, the entire supply chain financial system can be transformed from disorder to order until a stable structure is formed and the corresponding synergistic effect can be fully exerted [22].Strictly speaking, the supply chain finance collaborative management theory mainly includes two types, one is the coordination between the supply chain and the external environment, and the other is the cooperation and coordination between the internal supply chains.


### 3.2. System Dynamics

#### 3.2.1. Overview

System dynamics is a branch of analyzing and studying information feedback systems and is also a comprehensive new industry that combines the understanding of system problems and their solutions. The emergence of system dynamics began in 1969, and the founder was a professor at the Massachusetts Institute of Technology. Modeling starts from the internal microstructure of the system due to the unique philosophy of solving system dynamics problems: based on the view that structure determines behavior and causality, with the help of technical analysis of the internal relationship between the operation of the system structure and the dynamic behavior, the solution to the problem is found through computer simulation. Therefore, after system dynamics has become a new field, its application range has been expanding, covering almost all kinds of systems and going deep into various fields, and its theory has become increasingly mature [23, 24].The research of supply chain finance based on system dynamics is the cross research of supply chain management, supply chain finance, and system dynamics. Judging from the research results of the existing literature, the related research in each field is relatively extensive, and a considerable number of research results have been obtained.


#### 3.2.2. Basic Principles of System Dynamics

The basic principles of system dynamics are divided into two parts: basic elements and implementation steps.:(1)
Basic principlesSystem: it is an assemblage of disparate and interacting parts organically linked to accomplish a specific function for the same purpose.System boundaries: system boundaries determine what parts should be included in the model and what should be considered when modeling.Mutable state: it represents the accumulation of things. Its value represents the state of the variable system at a given time. It is the net difference between the inflow rate and the outflow rate, represented by a rectangle.Rate variables: rate variables use valve symbols to indicate how fast a specific level variable is changing.Cause-and-effect diagram: the first step in using system dynamics to analyze a problem is to identify the causal relationship between variables, reflecting how each factor affects the target risk. In the causal circuit diagram, if the change of factor A causes the related change of factor B, it will lead to the generation of “causal chain” with a positive chain and negative chain. The positive chain means that the factors change in the same direction. When factor A increases, the value of factor B will increase compared with the original. The negative chain means that the factors change in the opposite direction. When factor A increases, the value of factor B will decrease compared with the original value. The relationship can be shown in Figure3, for example.Flow graph: it represents the interconnected form of each variable level and each variable rate in the feedback loop and the interconnection feedback between each loop in the system. The stock-flow diagram is shown in Figure4.(2)
Implementation stepsThe flow of system dynamics implementation is shown in Figure5Figure 3
The causal chain.Figure 4
Stock-flow diagram.Figure 5
System dynamics modeling.


### 3.3. BP Algorithm

Artificial Neural Network (ANN) has the ability to store and use prior knowledge and at the same time has good aesthetic evaluation, such as self-adaptation, self-learning, parallel processing, nonlinearity, fault tolerance, and reasoning ability. This makes neural networks very suitable for dealing with inaccurate knowledge, mainly including causality, contradictions, and errors in the data [25].The basic BP algorithm formula is derived as follows.


#### 3.3.1. The Forward Propagation Process of the Input Signal

The inputneta of the a-th node of the hidden layer of the network is as follows:(1)neta=∑b=1Nwabxb+φa.The outputya of the a-th node in the hidden layer of the network is as follows:(2)ya=φneta=φ∑b=1Nwabxb+φa.The inputnetk of the k-th node of the network output layer is as follows:(3)netk=∑a=1qwkaya+ik=∑a=1qwkaφ∑b=1Nwabxb+φa+ik.The outputuk of the k-th node of the network output layer is as follows:(4)uk=γnetk=γ∑a=1qwkaya+ik=γ∑a=1qwkaφ∑b=1Nwabxb+φa+ik.


#### 3.3.2. Backpropagation Process of Output Error

The standard function of quadratic error for each samplep is Ep:(5)Ep=12∑k=1LZk−uk2.The function of the overall systematic error criterion for the training samples of P should be(6)Ep=12∑p=1P∑k=1LZkp−ukp2.According to the neural error gradient descent method, the correction amountΔWka of each weight value of the output layer, the correction amount Δak of each threshold value of the output layer, the correction amount ΔWab of each weight value of the hidden layer, and the correction amount Δφa of each threshold value of the hidden layer are sequentially adjusted.(7)Δwka=−μℜEℜwka;Δik=−μℜEℜik;Δwab=−μℜEℜwab;Δφa=−μℜEℜφa.The adjustment formula of the weights of the network output layer is as follows:(8)Δwka=−μℜEℜwka=−μℜEℜwkℜnetkℜwka=−μℜEℜukℜukℜnetkℜnetkℜwka.The adjustment formula of the threshold value of the network output layer is as follows:(9)Δik=−μℜEℜik=−μℜEℜnetkℜnetkℜwk=−μℜEℜukℜukℜnetkℜnetkℜik.The adjustment formula of the weights of the hidden layer of the network is as follows:(10)Δwab=−μℜEℜwab=−μℜEℜnetaℜnetaℜwab=−μℜEℜyaℜyaℜnetaℜnetaℜwab.The adjustment formula of the threshold of the hidden layer of the network is as follows:(11)Δφa=−μℜEℜφa=−μℜEℜnetaℜnetaℜφa=−μℜEℜyaℜyaℜnetaℜnetaℜφa.Also,(12)ℜGℜuk=−∑p=1P∑k=1LZkp−ukp,(13)ℜnetkℜHku=ya,ℜnetkℜik=1,ℜnetaℜHab=xb,ℜnetaℜφa=1.(14)ℜEℜya=−∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka,(15)ℜyaℜneta=ε′neta,(16)ℜukℜnetk=γ′netk.Finally, we obtained(17)Δwka=μ∑p=1P∑L=1LZkp−ukp⋅γ′netk⋅ya,(18)Δik=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk,(19)Δwab=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk⋅xb,(20)Δφa=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk.


## 3.1. Supply Chain Finance

### 3.1.1. Overview

The concept of supply chain finance (SCF) was first proposed in the field of logistics finance. It refers to a financial financing service provided for upstream and downstream small- and medium-sized enterprises in a specific supply chain of an industry [12–14]. Through the joint cooperation of financial capital and the real economy, it improves resource utilization, reduces inventory, reduces financing costs, and jointly creates a benign economic ecology in which financial institutions, real enterprises, and logistics enterprises coexist and benefit from each other. Supply chain collaboration refers to the mutual cooperation and coordination and resource efficiency of each node enterprise in the supply chain in order to improve the overall competitiveness of logistics. The existence of win-win consciousness makes supply chain enterprises rely on mutual trust, mutual commitment, and flexible negotiation and realize cooperative supply chain management [15]. Figure 1 shows the supply chain financing model.Figure 1
Supply chain finance model.To study the coordination of the supply chain financial system, we must first analyze the objects coordinated with the supply chain financial system. A comprehensive analysis of the supply chain financial system is the basis of supply chain collaboration research. The internal elements of the supply chain financial system mainly include financial institutions, outsourcing enterprises, key enterprises in the supply chain, and small- and medium-sized enterprises. Different cooperative relationships among the main players in the system form different types of financial supply chain system structures. The main function of supply chain financing, as an innovative financing model, is to provide intermediate services such as fund settlement [16, 17].


### 3.1.2. Structural Analysis of the Supply Chain Financial System

(1) The Structure of the Supply Chain Financial System under the Principal-Agent Mode. When small- and medium-sized enterprises in the supply chain are short of funds, under the traditional model, enterprises generally ask banks for financing needs and obtain loan services. However, based on the financing model under the traditional model, because the SMEs have less collateral and pledged assets, banks are worried that the risk is too great and may not provide financing services to SMEs. Since the logistics company participates in the entire transaction process of the supply chain, it has a deep understanding of the specific operation of the affiliated companies in the supply chain [18]. Therefore, if they can get the support of the logistics company, the bank can not only obtain financing but also monitor the actual operation status and effectively supervise the goods mortgaged by the enterprise when making loans, which can significantly reduce the risk of bank loans to a certain extent. The borrower business can also obtain financing in the corresponding amount.In this model, the role of the logistics company can be defined as the “principal-agent role.” At present, the logistics company only acts as a representative of the bank to supervise the basic operating conditions and commitments of the borrower’s business according to the needs of the bank and provide corresponding emergency response mechanisms when necessary. The motivation of the logistics company as the lead agent mainly comes from two aspects: one is the motivation to become a supply chain agent; the other is the supervision and consulting fees provided by financial institutions such as banks; the specific structure is shown in Figure2(a).Figure 2
Structure diagram of the supply chain financial system with different models. (a) Structural diagram of the supply chain financial system under the principal-agent mode. (b) Structural diagram of the supply chain financial system under the unified credit model. (c) Structural diagram of the supply chain financial system without the participation of logistics enterprises.
(a)(b)(c)(2) The Structure of the Supply Chain Financial System under the Unified Credit Mode. In the principal-agent mode, the moral hazard caused by information asymmetry is the key issue for banks to consider when financing, so banks have to take incentives and necessary restraint mechanisms for logistics enterprises, and these measures will inevitably lead to costs. Financial institutions have taken this into consideration, and on the basis of weighing costs and benefits and on the basis of simplifying operating procedures and reducing the human and material resources of financial institutions themselves, they have launched a supply chain financial system under a unified credit model [19].The supply chain financial system under the unified credit model means that the bank directly grants a fixed amount of loan to a logistics enterprise with a certain scale and good reputation. Under this model, the bank basically does not need to contact the borrowing company, the logistics company decides who and how much to lend, and the bank only needs to charge the logistics company for a preagreed capital gain. So this greatly reduces the operational process of the bank. On the other hand, because the unified credit model gives logistics enterprises a lot of autonomy, it can greatly stimulate the enthusiasm of logistics enterprises to carry out business and improve the efficiency of logistics operations, so it has also been developed to a certain extent in practice. The specific system structure diagram is shown in Figure2(b).(3) The Structure of the Supply Chain Financial System without the Participation of Logistics Enterprises. A supply chain financial system without the participation of logistics enterprises means that financial institutions control the actual background of supply chain transactions in the entire financing process according to their own wishes. This financing model is generally suitable for situations where the financing process is relatively simple, and the financial institution has a clearer understanding of the financing companies and the core companies in the supply chain. Due to the long-term strategic cooperative relationship between enterprises, banks can obtain real and effective information on the capital status of the entire supply chain and the operation status of enterprises without the help of third-party enterprises. Therefore, based on this situation, financial institutions do not have to introduce third-party logistics companies to increase financing costs, and because of the reduction of participants, the entire financial system becomes simpler [20, 21]. The specific structure diagram is shown in Figure 2(c).


### 3.1.3. Collaborative Management of Supply Chain Financial Systems

The concept of synergy first appeared in physical research, which originally refers to the combination of a variety of organizational individuals to form a whole and play a greater role and value than the sum of the individuals.The collaborative management of supply chain finance is proposed based on the concept of collaboration as a systematic discipline spanning natural sciences and social sciences, and the theory of collaborative management of supply chain finance studies the characteristics of regular changes among enterprises in the supply chain financial system. It is also recognized that there is an interactive and inseparable relationship between enterprises. Therefore, when supply chain finance based on system dynamics applies collaborative management theory, the entire supply chain financial system can be transformed from disorder to order until a stable structure is formed and the corresponding synergistic effect can be fully exerted [22].Strictly speaking, the supply chain finance collaborative management theory mainly includes two types, one is the coordination between the supply chain and the external environment, and the other is the cooperation and coordination between the internal supply chains.


## 3.1.1. Overview

The concept of supply chain finance (SCF) was first proposed in the field of logistics finance. It refers to a financial financing service provided for upstream and downstream small- and medium-sized enterprises in a specific supply chain of an industry [12–14]. Through the joint cooperation of financial capital and the real economy, it improves resource utilization, reduces inventory, reduces financing costs, and jointly creates a benign economic ecology in which financial institutions, real enterprises, and logistics enterprises coexist and benefit from each other. Supply chain collaboration refers to the mutual cooperation and coordination and resource efficiency of each node enterprise in the supply chain in order to improve the overall competitiveness of logistics. The existence of win-win consciousness makes supply chain enterprises rely on mutual trust, mutual commitment, and flexible negotiation and realize cooperative supply chain management [15]. Figure 1 shows the supply chain financing model.Figure 1
Supply chain finance model.To study the coordination of the supply chain financial system, we must first analyze the objects coordinated with the supply chain financial system. A comprehensive analysis of the supply chain financial system is the basis of supply chain collaboration research. The internal elements of the supply chain financial system mainly include financial institutions, outsourcing enterprises, key enterprises in the supply chain, and small- and medium-sized enterprises. Different cooperative relationships among the main players in the system form different types of financial supply chain system structures. The main function of supply chain financing, as an innovative financing model, is to provide intermediate services such as fund settlement [16, 17].


## 3.1.2. Structural Analysis of the Supply Chain Financial System

(1) The Structure of the Supply Chain Financial System under the Principal-Agent Mode. When small- and medium-sized enterprises in the supply chain are short of funds, under the traditional model, enterprises generally ask banks for financing needs and obtain loan services. However, based on the financing model under the traditional model, because the SMEs have less collateral and pledged assets, banks are worried that the risk is too great and may not provide financing services to SMEs. Since the logistics company participates in the entire transaction process of the supply chain, it has a deep understanding of the specific operation of the affiliated companies in the supply chain [18]. Therefore, if they can get the support of the logistics company, the bank can not only obtain financing but also monitor the actual operation status and effectively supervise the goods mortgaged by the enterprise when making loans, which can significantly reduce the risk of bank loans to a certain extent. The borrower business can also obtain financing in the corresponding amount.In this model, the role of the logistics company can be defined as the “principal-agent role.” At present, the logistics company only acts as a representative of the bank to supervise the basic operating conditions and commitments of the borrower’s business according to the needs of the bank and provide corresponding emergency response mechanisms when necessary. The motivation of the logistics company as the lead agent mainly comes from two aspects: one is the motivation to become a supply chain agent; the other is the supervision and consulting fees provided by financial institutions such as banks; the specific structure is shown in Figure2(a).Figure 2
Structure diagram of the supply chain financial system with different models. (a) Structural diagram of the supply chain financial system under the principal-agent mode. (b) Structural diagram of the supply chain financial system under the unified credit model. (c) Structural diagram of the supply chain financial system without the participation of logistics enterprises.
(a)(b)(c)(2) The Structure of the Supply Chain Financial System under the Unified Credit Mode. In the principal-agent mode, the moral hazard caused by information asymmetry is the key issue for banks to consider when financing, so banks have to take incentives and necessary restraint mechanisms for logistics enterprises, and these measures will inevitably lead to costs. Financial institutions have taken this into consideration, and on the basis of weighing costs and benefits and on the basis of simplifying operating procedures and reducing the human and material resources of financial institutions themselves, they have launched a supply chain financial system under a unified credit model [19].The supply chain financial system under the unified credit model means that the bank directly grants a fixed amount of loan to a logistics enterprise with a certain scale and good reputation. Under this model, the bank basically does not need to contact the borrowing company, the logistics company decides who and how much to lend, and the bank only needs to charge the logistics company for a preagreed capital gain. So this greatly reduces the operational process of the bank. On the other hand, because the unified credit model gives logistics enterprises a lot of autonomy, it can greatly stimulate the enthusiasm of logistics enterprises to carry out business and improve the efficiency of logistics operations, so it has also been developed to a certain extent in practice. The specific system structure diagram is shown in Figure2(b).(3) The Structure of the Supply Chain Financial System without the Participation of Logistics Enterprises. A supply chain financial system without the participation of logistics enterprises means that financial institutions control the actual background of supply chain transactions in the entire financing process according to their own wishes. This financing model is generally suitable for situations where the financing process is relatively simple, and the financial institution has a clearer understanding of the financing companies and the core companies in the supply chain. Due to the long-term strategic cooperative relationship between enterprises, banks can obtain real and effective information on the capital status of the entire supply chain and the operation status of enterprises without the help of third-party enterprises. Therefore, based on this situation, financial institutions do not have to introduce third-party logistics companies to increase financing costs, and because of the reduction of participants, the entire financial system becomes simpler [20, 21]. The specific structure diagram is shown in Figure 2(c).


## 3.1.3. Collaborative Management of Supply Chain Financial Systems

The concept of synergy first appeared in physical research, which originally refers to the combination of a variety of organizational individuals to form a whole and play a greater role and value than the sum of the individuals.The collaborative management of supply chain finance is proposed based on the concept of collaboration as a systematic discipline spanning natural sciences and social sciences, and the theory of collaborative management of supply chain finance studies the characteristics of regular changes among enterprises in the supply chain financial system. It is also recognized that there is an interactive and inseparable relationship between enterprises. Therefore, when supply chain finance based on system dynamics applies collaborative management theory, the entire supply chain financial system can be transformed from disorder to order until a stable structure is formed and the corresponding synergistic effect can be fully exerted [22].Strictly speaking, the supply chain finance collaborative management theory mainly includes two types, one is the coordination between the supply chain and the external environment, and the other is the cooperation and coordination between the internal supply chains.


## 3.2. System Dynamics

### 3.2.1. Overview

System dynamics is a branch of analyzing and studying information feedback systems and is also a comprehensive new industry that combines the understanding of system problems and their solutions. The emergence of system dynamics began in 1969, and the founder was a professor at the Massachusetts Institute of Technology. Modeling starts from the internal microstructure of the system due to the unique philosophy of solving system dynamics problems: based on the view that structure determines behavior and causality, with the help of technical analysis of the internal relationship between the operation of the system structure and the dynamic behavior, the solution to the problem is found through computer simulation. Therefore, after system dynamics has become a new field, its application range has been expanding, covering almost all kinds of systems and going deep into various fields, and its theory has become increasingly mature [23, 24].The research of supply chain finance based on system dynamics is the cross research of supply chain management, supply chain finance, and system dynamics. Judging from the research results of the existing literature, the related research in each field is relatively extensive, and a considerable number of research results have been obtained.


### 3.2.2. Basic Principles of System Dynamics

The basic principles of system dynamics are divided into two parts: basic elements and implementation steps.:(1)
Basic principlesSystem: it is an assemblage of disparate and interacting parts organically linked to accomplish a specific function for the same purpose.System boundaries: system boundaries determine what parts should be included in the model and what should be considered when modeling.Mutable state: it represents the accumulation of things. Its value represents the state of the variable system at a given time. It is the net difference between the inflow rate and the outflow rate, represented by a rectangle.Rate variables: rate variables use valve symbols to indicate how fast a specific level variable is changing.Cause-and-effect diagram: the first step in using system dynamics to analyze a problem is to identify the causal relationship between variables, reflecting how each factor affects the target risk. In the causal circuit diagram, if the change of factor A causes the related change of factor B, it will lead to the generation of “causal chain” with a positive chain and negative chain. The positive chain means that the factors change in the same direction. When factor A increases, the value of factor B will increase compared with the original. The negative chain means that the factors change in the opposite direction. When factor A increases, the value of factor B will decrease compared with the original value. The relationship can be shown in Figure3, for example.Flow graph: it represents the interconnected form of each variable level and each variable rate in the feedback loop and the interconnection feedback between each loop in the system. The stock-flow diagram is shown in Figure4.(2)
Implementation stepsThe flow of system dynamics implementation is shown in Figure5Figure 3
The causal chain.Figure 4
Stock-flow diagram.Figure 5
System dynamics modeling.


## 3.2.1. Overview

System dynamics is a branch of analyzing and studying information feedback systems and is also a comprehensive new industry that combines the understanding of system problems and their solutions. The emergence of system dynamics began in 1969, and the founder was a professor at the Massachusetts Institute of Technology. Modeling starts from the internal microstructure of the system due to the unique philosophy of solving system dynamics problems: based on the view that structure determines behavior and causality, with the help of technical analysis of the internal relationship between the operation of the system structure and the dynamic behavior, the solution to the problem is found through computer simulation. Therefore, after system dynamics has become a new field, its application range has been expanding, covering almost all kinds of systems and going deep into various fields, and its theory has become increasingly mature [23, 24].The research of supply chain finance based on system dynamics is the cross research of supply chain management, supply chain finance, and system dynamics. Judging from the research results of the existing literature, the related research in each field is relatively extensive, and a considerable number of research results have been obtained.


## 3.2.2. Basic Principles of System Dynamics

The basic principles of system dynamics are divided into two parts: basic elements and implementation steps.:(1)
Basic principlesSystem: it is an assemblage of disparate and interacting parts organically linked to accomplish a specific function for the same purpose.System boundaries: system boundaries determine what parts should be included in the model and what should be considered when modeling.Mutable state: it represents the accumulation of things. Its value represents the state of the variable system at a given time. It is the net difference between the inflow rate and the outflow rate, represented by a rectangle.Rate variables: rate variables use valve symbols to indicate how fast a specific level variable is changing.Cause-and-effect diagram: the first step in using system dynamics to analyze a problem is to identify the causal relationship between variables, reflecting how each factor affects the target risk. In the causal circuit diagram, if the change of factor A causes the related change of factor B, it will lead to the generation of “causal chain” with a positive chain and negative chain. The positive chain means that the factors change in the same direction. When factor A increases, the value of factor B will increase compared with the original. The negative chain means that the factors change in the opposite direction. When factor A increases, the value of factor B will decrease compared with the original value. The relationship can be shown in Figure3, for example.Flow graph: it represents the interconnected form of each variable level and each variable rate in the feedback loop and the interconnection feedback between each loop in the system. The stock-flow diagram is shown in Figure4.(2)
Implementation stepsThe flow of system dynamics implementation is shown in Figure5Figure 3
The causal chain.Figure 4
Stock-flow diagram.Figure 5
System dynamics modeling.


## 3.3. BP Algorithm

Artificial Neural Network (ANN) has the ability to store and use prior knowledge and at the same time has good aesthetic evaluation, such as self-adaptation, self-learning, parallel processing, nonlinearity, fault tolerance, and reasoning ability. This makes neural networks very suitable for dealing with inaccurate knowledge, mainly including causality, contradictions, and errors in the data [25].The basic BP algorithm formula is derived as follows.


### 3.3.1. The Forward Propagation Process of the Input Signal

The inputneta of the a-th node of the hidden layer of the network is as follows:(1)neta=∑b=1Nwabxb+φa.The outputya of the a-th node in the hidden layer of the network is as follows:(2)ya=φneta=φ∑b=1Nwabxb+φa.The inputnetk of the k-th node of the network output layer is as follows:(3)netk=∑a=1qwkaya+ik=∑a=1qwkaφ∑b=1Nwabxb+φa+ik.The outputuk of the k-th node of the network output layer is as follows:(4)uk=γnetk=γ∑a=1qwkaya+ik=γ∑a=1qwkaφ∑b=1Nwabxb+φa+ik.


### 3.3.2. Backpropagation Process of Output Error

The standard function of quadratic error for each samplep is Ep:(5)Ep=12∑k=1LZk−uk2.The function of the overall systematic error criterion for the training samples of P should be(6)Ep=12∑p=1P∑k=1LZkp−ukp2.According to the neural error gradient descent method, the correction amountΔWka of each weight value of the output layer, the correction amount Δak of each threshold value of the output layer, the correction amount ΔWab of each weight value of the hidden layer, and the correction amount Δφa of each threshold value of the hidden layer are sequentially adjusted.(7)Δwka=−μℜEℜwka;Δik=−μℜEℜik;Δwab=−μℜEℜwab;Δφa=−μℜEℜφa.The adjustment formula of the weights of the network output layer is as follows:(8)Δwka=−μℜEℜwka=−μℜEℜwkℜnetkℜwka=−μℜEℜukℜukℜnetkℜnetkℜwka.The adjustment formula of the threshold value of the network output layer is as follows:(9)Δik=−μℜEℜik=−μℜEℜnetkℜnetkℜwk=−μℜEℜukℜukℜnetkℜnetkℜik.The adjustment formula of the weights of the hidden layer of the network is as follows:(10)Δwab=−μℜEℜwab=−μℜEℜnetaℜnetaℜwab=−μℜEℜyaℜyaℜnetaℜnetaℜwab.The adjustment formula of the threshold of the hidden layer of the network is as follows:(11)Δφa=−μℜEℜφa=−μℜEℜnetaℜnetaℜφa=−μℜEℜyaℜyaℜnetaℜnetaℜφa.Also,(12)ℜGℜuk=−∑p=1P∑k=1LZkp−ukp,(13)ℜnetkℜHku=ya,ℜnetkℜik=1,ℜnetaℜHab=xb,ℜnetaℜφa=1.(14)ℜEℜya=−∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka,(15)ℜyaℜneta=ε′neta,(16)ℜukℜnetk=γ′netk.Finally, we obtained(17)Δwka=μ∑p=1P∑L=1LZkp−ukp⋅γ′netk⋅ya,(18)Δik=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk,(19)Δwab=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk⋅xb,(20)Δφa=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk.


## 3.3.1. The Forward Propagation Process of the Input Signal

The inputneta of the a-th node of the hidden layer of the network is as follows:(1)neta=∑b=1Nwabxb+φa.The outputya of the a-th node in the hidden layer of the network is as follows:(2)ya=φneta=φ∑b=1Nwabxb+φa.The inputnetk of the k-th node of the network output layer is as follows:(3)netk=∑a=1qwkaya+ik=∑a=1qwkaφ∑b=1Nwabxb+φa+ik.The outputuk of the k-th node of the network output layer is as follows:(4)uk=γnetk=γ∑a=1qwkaya+ik=γ∑a=1qwkaφ∑b=1Nwabxb+φa+ik.


## 3.3.2. Backpropagation Process of Output Error

The standard function of quadratic error for each samplep is Ep:(5)Ep=12∑k=1LZk−uk2.The function of the overall systematic error criterion for the training samples of P should be(6)Ep=12∑p=1P∑k=1LZkp−ukp2.According to the neural error gradient descent method, the correction amountΔWka of each weight value of the output layer, the correction amount Δak of each threshold value of the output layer, the correction amount ΔWab of each weight value of the hidden layer, and the correction amount Δφa of each threshold value of the hidden layer are sequentially adjusted.(7)Δwka=−μℜEℜwka;Δik=−μℜEℜik;Δwab=−μℜEℜwab;Δφa=−μℜEℜφa.The adjustment formula of the weights of the network output layer is as follows:(8)Δwka=−μℜEℜwka=−μℜEℜwkℜnetkℜwka=−μℜEℜukℜukℜnetkℜnetkℜwka.The adjustment formula of the threshold value of the network output layer is as follows:(9)Δik=−μℜEℜik=−μℜEℜnetkℜnetkℜwk=−μℜEℜukℜukℜnetkℜnetkℜik.The adjustment formula of the weights of the hidden layer of the network is as follows:(10)Δwab=−μℜEℜwab=−μℜEℜnetaℜnetaℜwab=−μℜEℜyaℜyaℜnetaℜnetaℜwab.The adjustment formula of the threshold of the hidden layer of the network is as follows:(11)Δφa=−μℜEℜφa=−μℜEℜnetaℜnetaℜφa=−μℜEℜyaℜyaℜnetaℜnetaℜφa.Also,(12)ℜGℜuk=−∑p=1P∑k=1LZkp−ukp,(13)ℜnetkℜHku=ya,ℜnetkℜik=1,ℜnetaℜHab=xb,ℜnetaℜφa=1.(14)ℜEℜya=−∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka,(15)ℜyaℜneta=ε′neta,(16)ℜukℜnetk=γ′netk.Finally, we obtained(17)Δwka=μ∑p=1P∑L=1LZkp−ukp⋅γ′netk⋅ya,(18)Δik=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk,(19)Δwab=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk⋅xb,(20)Δφa=μ∑p=1P∑k=1LZkp−ukp⋅γ′netk⋅wka⋅ε′netk.


## 4. Collaborative Optimization Experiment of the Supply Chain Financial System Based on System Dynamics

### 4.1. The Causal Feedback Loop Diagram of the Supply Chain Financial System

#### 4.1.1. Causal Circuit Diagram of Supply Chain Financing Demand

China’s economy is in a period of rapid development, which brings both opportunities and challenges to every individual in the economic system. The entire supply chain can profit from increasing transaction volumes. The increase in transaction volume can certainly bring about an increase in business volume for small- and medium-sized enterprises, but they also have to advance a large amount of working capital, making financing increasingly difficult, and the risk of capital chain breakage is increasing. The financing difficulties of SMEs will first hinder their own development and then will drag down the entire supply chain, making the core enterprises with competitive advantages in the supply chain have to slow down the pace of development. As an innovative financial model, supply chain finance can help small- and medium-sized enterprises get rid of the dilemma of financing difficulties [26, 27]. According to the different positions of the funding gap in the supply chain, supply chain financing methods can be divided into three modes: warehouse confirmation function (based on prepaid accounts), accounts receivable mode (accounts receivable based model), and financing warehouse operation (stock-based functionality). The healthy and smooth development of supply chain financing can provide financial support for small- and medium-sized enterprises, thereby promoting the development of the entire supply chain. The causal circuit diagram is shown in Figure 6.Figure 6
Supply chain financing needs diagram.


#### 4.1.2. Cooperative Process Causal Loop Diagram

Because of the interconnection between banks, SMEs as financiers, and third-party logistics companies, there are three modes. In this paper, the causal loop diagram of the synergy process is established by taking the Rongtong warehouse model as an example, and the causal loop diagram of the synergy process is shown in Figure7.Figure 7
Causal loop diagram of system coprocess.It can be seen from the positive feedback loop R1 that the increasing transaction volume improves the efficiency and competitiveness of the enterprise, which in turn promotes the transaction volume of the enterprise. This cycle will inevitably make the overall capacity and scale of the enterprise gradually increase. However, with the increase in the transaction volume of the enterprise, the phenomenon of enterprise goods pledge will also be aggravated. Just as shown in the negative feedback loop B1, if it cannot be dealt with in time, the enterprise will fall into the dilemma of the flow of funds, which will affect the overall competitiveness of the enterprise. When an enterprise is faced with a shortage of funds, the first solution for the enterprise is to apply for financing to the bank, but due to the inherent characteristics of the enterprise itself, it cannot provide the bank with a sufficient degree of repayment guarantee. Banks will reject SMEs’ financing applications due to the high financing risk factor, thereby accelerating the flow of corporate funds, such as positive feedback loop R2.When an enterprise borrows from a bank, because the main source of profit for banks is the interest rate difference between deposits and loans, although the bank has a profit motive, it also has a high-risk awareness and will not cover the financing needs of small- and medium-sized enterprises in the supply chain, because such enterprises have high borrowing risks and are more difficult to recover. The emergence of the warehouse financing model can solve this problem smoothly. Banks can obtain operating profits through the financing services of the financial warehouse model and at the same time can improve their risk management capabilities and technical levels. The technical level of bank risk prevention is to prevent problems before they occur and to establish an effective early warning mechanism to avoid adverse consequences of risks. The management and control ability is reflected in coordinating the relationship with logistics and small- and medium-sized enterprises to ensure their own profits. As shown by the positive feedback loops R6 and R7, these will affect the likelihood of risk in the supply chain financial system [28, 29].In addition, the normal operation of the supply chain financial system requires the support of logistics enterprises, which use their professional capabilities and resources to act as the bank’s agent to help them supervise the inventory of small- and medium-sized enterprises in the supply chain. At the same time, the demand for logistics services has also increased. That will make the economic benefits of logistics enterprises increase, and the investment in themselves will increase. The development of information technology and the improvement of the management level of logistics enterprises not only improve their own service level but also reduce the risk level in the process of supply chain finance operation, as shown by the positive feedback loops R3, R4, and R5. By analyzing the relationship between the three-party enterprises, the operation mechanism of the causal loop diagram of the financial warehouse model is explained in detail, and the collaborative process of the system is also explained, which is the basis of the system dynamics flow diagram established next.


### 4.2. Construction of SD Flow Diagram for the Coordinated Development of the Supply Chain Financial System

The next part of this paper will use the principles of system dynamics to model the coordinated development of the system, explore the specific relationship between the degree of coordination and the parameters by changing the values of the control parameters in the model, and find out the key links of coordinated development, and the proper value of key links can promote the coordinated and orderly development of the entire supply chain financial system.


#### 4.2.1. The Process of the Financing Warehouse Model

This paper sets the following background for the establishment of the model under the confirmed position mode.Assuming that company A conducts a transaction with chemical factoryZ, the specific process of this transaction is shown in Figure 8.Figure 8
Operation process of the confirmed warehouse mode.


#### 4.2.2. Construction of SD Flow Graph in the Rongtong Warehouse Mode

This paper sets up the following background for the model establishment under the operation mode of the intermediary warehouse.Company A is a typical small- and medium-sized enterprise whose main business is steel processing, warehousing, distribution, and trade. The operating characteristics of such companies are that the purchase and sale are carried out at the same time. Although the inventory turnover rate is high, the amount of inventory retained is huge, which occupies a large amount of working capital. With the expansion of the company’s scale, this situation of tight liquidity has further deteriorated, and the capital chain of company A is facing the risk of rupture at any time. However, because company A has the typical characteristics of small- and medium-sized enterprises and lacks real estate with guaranteed value, it is difficult to obtain bank loans under the traditional financial model. However, company A is in a supply chain financial system and can use the supply chain financial business to obtain supplementary liquidity. Suppose that GP bank is a financial institution in the system, accepting company A’s stock as a pledge guarantee and requiring company A to store the pledged goods in the warehouse of the designated logistics company while trusting the logistics supervised by company A of the company. The company has to pay a deposit to the logistics company, and the logistics company releases the goods to company A based on the percentage of the deposit paid by company A.This paper proposes the following five assumptions in order to establish the financing warehouse model: Company A purchases new products as pledges for financing guarantees.The price of goods is stable, and there will be no pledged goods or margin calls caused by price changes.Company A’s inventory cost is 0.Company A’s cash stock is initially 0, and the product can only be reordered after the product is sold in the initial stage.During the transaction, the goods do not need to be returned to the warehouse of company A, and the goods are directly issued by the warehouse of the logistics company. The specific model is shown in Figure9.Figure 9
SD diagram of the financing warehouse model.The order quantity only exists for 5 weeks because the model simulates only one cycle. The initial order quantity is 0. Whenever company B needs financing, it pledges the existing inventory (mainly nonessential inventory) to the bank and uses the obtained loan capital to purchase new goods (mainly necessary inventory). Assuming that the initial inventory is 5000 pieces. It has been assumed that the pledged inventory loan is the only financing channel of company B. Therefore, when financing is required, company A can only send the inventory to the warehouse of the logistics enterprise designated by the bank.


#### 4.2.3. Process of Accounts Receivable Model

This paper sets the following background for the model under the accounts receivable financing mode and uses VENSIM software for modeling analysis. The model background is described as follows.Company B is a small- and medium-sized enterprise specializing in automotive electronic parts. It has established long-term and stable cooperative relations with downstream car manufacturers, and the overall operation is good. However, since the car factory is the core enterprise in the supply chain, company B is always at a disadvantage in the negotiation with the car factory, so it has to maintain the cooperation with the car factory through credit preferential policies such as extending the collection period. The turnover of accounts receivable is insufficient, leading to a large amount of working capital of company B being occupied by accounts receivable, and the capital chain is narrow. GP bank uses the accounts receivable model to solve this problem, and the next transaction model diagram in the background of the transaction between these two companies is shown in Figure10.Figure 10
Accounts receivable schema process.


### 4.3. Model Simulation

After the above analysis, it is not difficult to find that the supply chain and the financial industry are not two parallel lines. The two are interconnected through multiple links, forming a system under the combined effect of internal element competition and synergy. Due to the consistency of goals, supply chain enterprises and financial institutions within the system can achieve a win-win situation, and the entire system can also stimulate macroeconomic development outside the system. This part of the content section will establish a dynamic model of the supply chain financial system and explore the relationship between the dependence of banks and logistics enterprises and economic benefits through the analysis of dynamic feedback relationships.On the basis of the dynamic flow diagram of the supply chain financial system constructed, this section selects the “bank input” as an adjustment variable in the system dynamics model of the coordinated development of banks and supply chains. Through a comprehensive analysis of the model construction principle and feedback relationship, this paper believes that the dependence between banks and supply chain enterprises changes in the same direction as the bank’s investment in the supply chain. The model simulation in this paper will give the corresponding expected economic benefits according to the level of dependence so that the relationship between the two can be judged.Through analysis, this paper adopts bank input as a surrogate variable of system dependence. In the simulation process, keeping other factors unchanged, only the “bank input” is changed, and its value is increased from 0.1 to 0.2. The simulation results of the system dynamics model are shown in Table1.Table 1
Comparison of economic benefits after adjusting bank input value.
TimeBank benefit GDP simulation value (0.1)Supply chain enterprise GDP simulation value (0.1)GDP simulated value (0.1)TimeBank benefit GDP simulation value (0.2)Supply chain enterprise GDP simulation value (0.2)GDP simulated value (0.2)201251248320381.552351620125973125839.7562849201355270121849.4617923201363568227481.4653182201459284122938.3725825201467292229451.7774261201563683323491.5819631201578902132468.1894814201675301024255.19362862016109528434257.21214673201787494225295.49841712017118094236441.61336183201899582826732.311849622018137215438357.214381922019109487427851.713598902019142895040941.315439142020113590128964.214783952020150852441026.016948132021127438329630.415383922021161214942117.31748525The results in Table1 show that as long as the dependence of the financial industry and supply chain is slightly increased, increasing the “bank input” from 0.1 to 2 can bring considerable economic benefits in the long run. As far as the simulation results are concerned, in 2021, the bank’s income can increase from 127,438.3 billion yuan to 161,214.9 billion yuan, an increase of 24.50%, and the supply chain output value can increase from 2963.04 billion yuan to 4211.73 billion yuan, an increase of 42.14%. The contribution to GDP can increase from 153,839.2 billion yuan to 174,852.5 billion yuan, an increase of 13.66%, of which the promotion effect on the supply chain is the most significant, which can also be seen in Figure 11.Figure 11
Comparison of the effects after the adjustment of the indicators: (a) comparison of simulated bank benefits and GDP effects after index adjustment; (b) comparison of simulation effects of enterprise simulation values after index adjustment.
(a)(b)


## 4.1. The Causal Feedback Loop Diagram of the Supply Chain Financial System

### 4.1.1. Causal Circuit Diagram of Supply Chain Financing Demand

China’s economy is in a period of rapid development, which brings both opportunities and challenges to every individual in the economic system. The entire supply chain can profit from increasing transaction volumes. The increase in transaction volume can certainly bring about an increase in business volume for small- and medium-sized enterprises, but they also have to advance a large amount of working capital, making financing increasingly difficult, and the risk of capital chain breakage is increasing. The financing difficulties of SMEs will first hinder their own development and then will drag down the entire supply chain, making the core enterprises with competitive advantages in the supply chain have to slow down the pace of development. As an innovative financial model, supply chain finance can help small- and medium-sized enterprises get rid of the dilemma of financing difficulties [26, 27]. According to the different positions of the funding gap in the supply chain, supply chain financing methods can be divided into three modes: warehouse confirmation function (based on prepaid accounts), accounts receivable mode (accounts receivable based model), and financing warehouse operation (stock-based functionality). The healthy and smooth development of supply chain financing can provide financial support for small- and medium-sized enterprises, thereby promoting the development of the entire supply chain. The causal circuit diagram is shown in Figure 6.Figure 6
Supply chain financing needs diagram.


### 4.1.2. Cooperative Process Causal Loop Diagram

Because of the interconnection between banks, SMEs as financiers, and third-party logistics companies, there are three modes. In this paper, the causal loop diagram of the synergy process is established by taking the Rongtong warehouse model as an example, and the causal loop diagram of the synergy process is shown in Figure7.Figure 7
Causal loop diagram of system coprocess.It can be seen from the positive feedback loop R1 that the increasing transaction volume improves the efficiency and competitiveness of the enterprise, which in turn promotes the transaction volume of the enterprise. This cycle will inevitably make the overall capacity and scale of the enterprise gradually increase. However, with the increase in the transaction volume of the enterprise, the phenomenon of enterprise goods pledge will also be aggravated. Just as shown in the negative feedback loop B1, if it cannot be dealt with in time, the enterprise will fall into the dilemma of the flow of funds, which will affect the overall competitiveness of the enterprise. When an enterprise is faced with a shortage of funds, the first solution for the enterprise is to apply for financing to the bank, but due to the inherent characteristics of the enterprise itself, it cannot provide the bank with a sufficient degree of repayment guarantee. Banks will reject SMEs’ financing applications due to the high financing risk factor, thereby accelerating the flow of corporate funds, such as positive feedback loop R2.When an enterprise borrows from a bank, because the main source of profit for banks is the interest rate difference between deposits and loans, although the bank has a profit motive, it also has a high-risk awareness and will not cover the financing needs of small- and medium-sized enterprises in the supply chain, because such enterprises have high borrowing risks and are more difficult to recover. The emergence of the warehouse financing model can solve this problem smoothly. Banks can obtain operating profits through the financing services of the financial warehouse model and at the same time can improve their risk management capabilities and technical levels. The technical level of bank risk prevention is to prevent problems before they occur and to establish an effective early warning mechanism to avoid adverse consequences of risks. The management and control ability is reflected in coordinating the relationship with logistics and small- and medium-sized enterprises to ensure their own profits. As shown by the positive feedback loops R6 and R7, these will affect the likelihood of risk in the supply chain financial system [28, 29].In addition, the normal operation of the supply chain financial system requires the support of logistics enterprises, which use their professional capabilities and resources to act as the bank’s agent to help them supervise the inventory of small- and medium-sized enterprises in the supply chain. At the same time, the demand for logistics services has also increased. That will make the economic benefits of logistics enterprises increase, and the investment in themselves will increase. The development of information technology and the improvement of the management level of logistics enterprises not only improve their own service level but also reduce the risk level in the process of supply chain finance operation, as shown by the positive feedback loops R3, R4, and R5. By analyzing the relationship between the three-party enterprises, the operation mechanism of the causal loop diagram of the financial warehouse model is explained in detail, and the collaborative process of the system is also explained, which is the basis of the system dynamics flow diagram established next.


## 4.1.1. Causal Circuit Diagram of Supply Chain Financing Demand

China’s economy is in a period of rapid development, which brings both opportunities and challenges to every individual in the economic system. The entire supply chain can profit from increasing transaction volumes. The increase in transaction volume can certainly bring about an increase in business volume for small- and medium-sized enterprises, but they also have to advance a large amount of working capital, making financing increasingly difficult, and the risk of capital chain breakage is increasing. The financing difficulties of SMEs will first hinder their own development and then will drag down the entire supply chain, making the core enterprises with competitive advantages in the supply chain have to slow down the pace of development. As an innovative financial model, supply chain finance can help small- and medium-sized enterprises get rid of the dilemma of financing difficulties [26, 27]. According to the different positions of the funding gap in the supply chain, supply chain financing methods can be divided into three modes: warehouse confirmation function (based on prepaid accounts), accounts receivable mode (accounts receivable based model), and financing warehouse operation (stock-based functionality). The healthy and smooth development of supply chain financing can provide financial support for small- and medium-sized enterprises, thereby promoting the development of the entire supply chain. The causal circuit diagram is shown in Figure 6.Figure 6
Supply chain financing needs diagram.


## 4.1.2. Cooperative Process Causal Loop Diagram

Because of the interconnection between banks, SMEs as financiers, and third-party logistics companies, there are three modes. In this paper, the causal loop diagram of the synergy process is established by taking the Rongtong warehouse model as an example, and the causal loop diagram of the synergy process is shown in Figure7.Figure 7
Causal loop diagram of system coprocess.It can be seen from the positive feedback loop R1 that the increasing transaction volume improves the efficiency and competitiveness of the enterprise, which in turn promotes the transaction volume of the enterprise. This cycle will inevitably make the overall capacity and scale of the enterprise gradually increase. However, with the increase in the transaction volume of the enterprise, the phenomenon of enterprise goods pledge will also be aggravated. Just as shown in the negative feedback loop B1, if it cannot be dealt with in time, the enterprise will fall into the dilemma of the flow of funds, which will affect the overall competitiveness of the enterprise. When an enterprise is faced with a shortage of funds, the first solution for the enterprise is to apply for financing to the bank, but due to the inherent characteristics of the enterprise itself, it cannot provide the bank with a sufficient degree of repayment guarantee. Banks will reject SMEs’ financing applications due to the high financing risk factor, thereby accelerating the flow of corporate funds, such as positive feedback loop R2.When an enterprise borrows from a bank, because the main source of profit for banks is the interest rate difference between deposits and loans, although the bank has a profit motive, it also has a high-risk awareness and will not cover the financing needs of small- and medium-sized enterprises in the supply chain, because such enterprises have high borrowing risks and are more difficult to recover. The emergence of the warehouse financing model can solve this problem smoothly. Banks can obtain operating profits through the financing services of the financial warehouse model and at the same time can improve their risk management capabilities and technical levels. The technical level of bank risk prevention is to prevent problems before they occur and to establish an effective early warning mechanism to avoid adverse consequences of risks. The management and control ability is reflected in coordinating the relationship with logistics and small- and medium-sized enterprises to ensure their own profits. As shown by the positive feedback loops R6 and R7, these will affect the likelihood of risk in the supply chain financial system [28, 29].In addition, the normal operation of the supply chain financial system requires the support of logistics enterprises, which use their professional capabilities and resources to act as the bank’s agent to help them supervise the inventory of small- and medium-sized enterprises in the supply chain. At the same time, the demand for logistics services has also increased. That will make the economic benefits of logistics enterprises increase, and the investment in themselves will increase. The development of information technology and the improvement of the management level of logistics enterprises not only improve their own service level but also reduce the risk level in the process of supply chain finance operation, as shown by the positive feedback loops R3, R4, and R5. By analyzing the relationship between the three-party enterprises, the operation mechanism of the causal loop diagram of the financial warehouse model is explained in detail, and the collaborative process of the system is also explained, which is the basis of the system dynamics flow diagram established next.


## 4.2. Construction of SD Flow Diagram for the Coordinated Development of the Supply Chain Financial System

The next part of this paper will use the principles of system dynamics to model the coordinated development of the system, explore the specific relationship between the degree of coordination and the parameters by changing the values of the control parameters in the model, and find out the key links of coordinated development, and the proper value of key links can promote the coordinated and orderly development of the entire supply chain financial system.


### 4.2.1. The Process of the Financing Warehouse Model

This paper sets the following background for the establishment of the model under the confirmed position mode.Assuming that company A conducts a transaction with chemical factoryZ, the specific process of this transaction is shown in Figure 8.Figure 8
Operation process of the confirmed warehouse mode.


### 4.2.2. Construction of SD Flow Graph in the Rongtong Warehouse Mode

This paper sets up the following background for the model establishment under the operation mode of the intermediary warehouse.Company A is a typical small- and medium-sized enterprise whose main business is steel processing, warehousing, distribution, and trade. The operating characteristics of such companies are that the purchase and sale are carried out at the same time. Although the inventory turnover rate is high, the amount of inventory retained is huge, which occupies a large amount of working capital. With the expansion of the company’s scale, this situation of tight liquidity has further deteriorated, and the capital chain of company A is facing the risk of rupture at any time. However, because company A has the typical characteristics of small- and medium-sized enterprises and lacks real estate with guaranteed value, it is difficult to obtain bank loans under the traditional financial model. However, company A is in a supply chain financial system and can use the supply chain financial business to obtain supplementary liquidity. Suppose that GP bank is a financial institution in the system, accepting company A’s stock as a pledge guarantee and requiring company A to store the pledged goods in the warehouse of the designated logistics company while trusting the logistics supervised by company A of the company. The company has to pay a deposit to the logistics company, and the logistics company releases the goods to company A based on the percentage of the deposit paid by company A.This paper proposes the following five assumptions in order to establish the financing warehouse model: Company A purchases new products as pledges for financing guarantees.The price of goods is stable, and there will be no pledged goods or margin calls caused by price changes.Company A’s inventory cost is 0.Company A’s cash stock is initially 0, and the product can only be reordered after the product is sold in the initial stage.During the transaction, the goods do not need to be returned to the warehouse of company A, and the goods are directly issued by the warehouse of the logistics company. The specific model is shown in Figure9.Figure 9
SD diagram of the financing warehouse model.The order quantity only exists for 5 weeks because the model simulates only one cycle. The initial order quantity is 0. Whenever company B needs financing, it pledges the existing inventory (mainly nonessential inventory) to the bank and uses the obtained loan capital to purchase new goods (mainly necessary inventory). Assuming that the initial inventory is 5000 pieces. It has been assumed that the pledged inventory loan is the only financing channel of company B. Therefore, when financing is required, company A can only send the inventory to the warehouse of the logistics enterprise designated by the bank.


### 4.2.3. Process of Accounts Receivable Model

This paper sets the following background for the model under the accounts receivable financing mode and uses VENSIM software for modeling analysis. The model background is described as follows.Company B is a small- and medium-sized enterprise specializing in automotive electronic parts. It has established long-term and stable cooperative relations with downstream car manufacturers, and the overall operation is good. However, since the car factory is the core enterprise in the supply chain, company B is always at a disadvantage in the negotiation with the car factory, so it has to maintain the cooperation with the car factory through credit preferential policies such as extending the collection period. The turnover of accounts receivable is insufficient, leading to a large amount of working capital of company B being occupied by accounts receivable, and the capital chain is narrow. GP bank uses the accounts receivable model to solve this problem, and the next transaction model diagram in the background of the transaction between these two companies is shown in Figure10.Figure 10
Accounts receivable schema process.


## 4.2.1. The Process of the Financing Warehouse Model

This paper sets the following background for the establishment of the model under the confirmed position mode.Assuming that company A conducts a transaction with chemical factoryZ, the specific process of this transaction is shown in Figure 8.Figure 8
Operation process of the confirmed warehouse mode.


## 4.2.2. Construction of SD Flow Graph in the Rongtong Warehouse Mode

This paper sets up the following background for the model establishment under the operation mode of the intermediary warehouse.Company A is a typical small- and medium-sized enterprise whose main business is steel processing, warehousing, distribution, and trade. The operating characteristics of such companies are that the purchase and sale are carried out at the same time. Although the inventory turnover rate is high, the amount of inventory retained is huge, which occupies a large amount of working capital. With the expansion of the company’s scale, this situation of tight liquidity has further deteriorated, and the capital chain of company A is facing the risk of rupture at any time. However, because company A has the typical characteristics of small- and medium-sized enterprises and lacks real estate with guaranteed value, it is difficult to obtain bank loans under the traditional financial model. However, company A is in a supply chain financial system and can use the supply chain financial business to obtain supplementary liquidity. Suppose that GP bank is a financial institution in the system, accepting company A’s stock as a pledge guarantee and requiring company A to store the pledged goods in the warehouse of the designated logistics company while trusting the logistics supervised by company A of the company. The company has to pay a deposit to the logistics company, and the logistics company releases the goods to company A based on the percentage of the deposit paid by company A.This paper proposes the following five assumptions in order to establish the financing warehouse model: Company A purchases new products as pledges for financing guarantees.The price of goods is stable, and there will be no pledged goods or margin calls caused by price changes.Company A’s inventory cost is 0.Company A’s cash stock is initially 0, and the product can only be reordered after the product is sold in the initial stage.During the transaction, the goods do not need to be returned to the warehouse of company A, and the goods are directly issued by the warehouse of the logistics company. The specific model is shown in Figure9.Figure 9
SD diagram of the financing warehouse model.The order quantity only exists for 5 weeks because the model simulates only one cycle. The initial order quantity is 0. Whenever company B needs financing, it pledges the existing inventory (mainly nonessential inventory) to the bank and uses the obtained loan capital to purchase new goods (mainly necessary inventory). Assuming that the initial inventory is 5000 pieces. It has been assumed that the pledged inventory loan is the only financing channel of company B. Therefore, when financing is required, company A can only send the inventory to the warehouse of the logistics enterprise designated by the bank.


## 4.2.3. Process of Accounts Receivable Model

This paper sets the following background for the model under the accounts receivable financing mode and uses VENSIM software for modeling analysis. The model background is described as follows.Company B is a small- and medium-sized enterprise specializing in automotive electronic parts. It has established long-term and stable cooperative relations with downstream car manufacturers, and the overall operation is good. However, since the car factory is the core enterprise in the supply chain, company B is always at a disadvantage in the negotiation with the car factory, so it has to maintain the cooperation with the car factory through credit preferential policies such as extending the collection period. The turnover of accounts receivable is insufficient, leading to a large amount of working capital of company B being occupied by accounts receivable, and the capital chain is narrow. GP bank uses the accounts receivable model to solve this problem, and the next transaction model diagram in the background of the transaction between these two companies is shown in Figure10.Figure 10
Accounts receivable schema process.


## 4.3. Model Simulation

After the above analysis, it is not difficult to find that the supply chain and the financial industry are not two parallel lines. The two are interconnected through multiple links, forming a system under the combined effect of internal element competition and synergy. Due to the consistency of goals, supply chain enterprises and financial institutions within the system can achieve a win-win situation, and the entire system can also stimulate macroeconomic development outside the system. This part of the content section will establish a dynamic model of the supply chain financial system and explore the relationship between the dependence of banks and logistics enterprises and economic benefits through the analysis of dynamic feedback relationships.On the basis of the dynamic flow diagram of the supply chain financial system constructed, this section selects the “bank input” as an adjustment variable in the system dynamics model of the coordinated development of banks and supply chains. Through a comprehensive analysis of the model construction principle and feedback relationship, this paper believes that the dependence between banks and supply chain enterprises changes in the same direction as the bank’s investment in the supply chain. The model simulation in this paper will give the corresponding expected economic benefits according to the level of dependence so that the relationship between the two can be judged.Through analysis, this paper adopts bank input as a surrogate variable of system dependence. In the simulation process, keeping other factors unchanged, only the “bank input” is changed, and its value is increased from 0.1 to 0.2. The simulation results of the system dynamics model are shown in Table1.Table 1
Comparison of economic benefits after adjusting bank input value.
TimeBank benefit GDP simulation value (0.1)Supply chain enterprise GDP simulation value (0.1)GDP simulated value (0.1)TimeBank benefit GDP simulation value (0.2)Supply chain enterprise GDP simulation value (0.2)GDP simulated value (0.2)201251248320381.552351620125973125839.7562849201355270121849.4617923201363568227481.4653182201459284122938.3725825201467292229451.7774261201563683323491.5819631201578902132468.1894814201675301024255.19362862016109528434257.21214673201787494225295.49841712017118094236441.61336183201899582826732.311849622018137215438357.214381922019109487427851.713598902019142895040941.315439142020113590128964.214783952020150852441026.016948132021127438329630.415383922021161214942117.31748525The results in Table1 show that as long as the dependence of the financial industry and supply chain is slightly increased, increasing the “bank input” from 0.1 to 2 can bring considerable economic benefits in the long run. As far as the simulation results are concerned, in 2021, the bank’s income can increase from 127,438.3 billion yuan to 161,214.9 billion yuan, an increase of 24.50%, and the supply chain output value can increase from 2963.04 billion yuan to 4211.73 billion yuan, an increase of 42.14%. The contribution to GDP can increase from 153,839.2 billion yuan to 174,852.5 billion yuan, an increase of 13.66%, of which the promotion effect on the supply chain is the most significant, which can also be seen in Figure 11.Figure 11
Comparison of the effects after the adjustment of the indicators: (a) comparison of simulated bank benefits and GDP effects after index adjustment; (b) comparison of simulation effects of enterprise simulation values after index adjustment.
(a)(b)


## 5. Discussion

Through the study of relevant knowledge points of supply chain finance literature works, this paper has initially mastered the relevant basic knowledge and analyzed how to conduct research on the coordinated development of supply chain finance based on system dynamics. The algorithm of BP neural network is summarized, the structure of supply chain finance system is studied, the basic principle of system dynamics is explored, and the applicability of system dynamics in supply chain finance is analyzed through experiments.Synergy is a scientific method to study the transformation of a system from disorder to order. This transformation is a complex large system formed by the interdependence and mutual support of various subsystems. Coordinated development is the driving force and means to achieve sustainable development. Sustainable development is a comprehensive event and the inner unity of coordinated development sustainability. The key is coordination, cooperation, complementarity, and synchronization within and between systems. In the process of developing and developing the supply chain financial system, if the coordination problem is ignored or underestimated, the system will no longer be able to coexist and develop for a long time.Through the experimental analysis, this paper shows that, based on the SD supply chain financial financing model, the difference between the mortgage interest rate of the traditional financing model and the accounts receivable mortgage financing model is compared intuitively. Benefit calculations show that financial firms in the supply chain can improve the efficiency and turnover rate of SME suppliers’ capital in order to achieve a tripartite profit situation between SME suppliers and promote long-term stable growth of the entire supply chain.


## 6. Conclusions

This paper makes a comprehensive analysis of the supply chain financial system and its coordinated development, but there are still many shortcomings in the research, which need to be further improved in the future. In this paper, the research on the supply chain financial system mainly focuses on the interior, and the research on the adaptability of the system to the environment and the adjustment process under the nonadaptive state is insufficient. Future research can improve this aspect. This paper ignores the influence of external environment, such as economy, society, politics, and law, when establishing the system dynamics model. In future research, we may consider adding environmental impact factor variables to the model to improve the predictive ability of the model solution. This paper does not consider the impact of credit rating on corporate loans. In the future, the model can be further improved in combination with the research part of credit rating.



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*Source: 3005816-2022-06-22.xml*