Modelling and simulation of the balance of supply chain ecosystem

The supply chain is a functional network chain structure composed of nodes such as suppliers, manufacturers, distributors, retailers and customers (Santoso et al., 2005; Nagurney et al., 2002). In the supply chain network, information flow acts as a link to connect each node, affecting the logistics and capital flow. Information flow plays an irreplaceable role in supply chain management. Inventory information, order information, market information, and logistics information are all part of the information flow. Any mishandling of information will affect the normal operation of the supply chain system. Therefore, although the supply chain network structure is morphologically affected by material flow, it is essentially based on information flow. All enterprise nodes in the supply chain are constantly generating, transmitting, consuming, and decomposing information, thereby forming a topological structure network of information transmission. The information ecosystem of supply chain is an organic whole composed of the interaction and interplay between the information subject, the information ecological environment and the information in the supply chain environment (Vincent and Macleod, 2011; Tao, 2014). In the current supply chain information ecosystem, the problem of information ecological imbalance is very common. The disorderly production of information producers leads to the difficulty of information dissemination, the flooding of useless and distorted information hinders the information users from exploring useful information, and the weakness in information decomposition deepens the of the above problems. In order to promote the development of the supply chain information ecosystem in a balanced direction, it is necessary to explore the relationship between information production, transmission, consumption and decomposition, so that the various elements in the system can be reasonably distributed and the operational structure is more efficient.

The information ecological balance of supply chain is an indispensable part of constructing the ecological civilization society. As the most basic organizational form of enterprise information ecosystem, the dynamic balance of supply chain information ecological chain is the basic prerequisite for the harmony and stability of supply chain information ecosystem. Study on dynamic balance mechanism of information ecological chain of supply chain can clarify the motive and main characteristics of dynamic balance or imbalance of information ecological chain of supply chain, so as to provide theoretical guidance for maintaining or restoring balance.

A supply chain ecosystem consists of the elements of the supply chain and the entities that influence the goods, information and financial flows through the supply chain (Viswanadham and Samvedi, 2013; Chaplin-Kramer et al., 2016). At present, in the research of network information ecosystem, Lou et al. (2013; 2014) systematically studied the dynamic balance of network information ecological chain, symbiosis and mutual benefit, increments of value, collaborative competition, and information circulation etc. From the perspective of supply chain, Fan (2011) proposed in terms of the information ecosystem balance to rebuild the supply chain business process through information integration platform and establish a dynamic alliance, in order to achieve the dynamic balance of the information ecosystem. Huo et al. (2016) empirically studied the relationship between the degree of information standardization, information transmission ability and willingness to send, the willingness to receive information and the ability to receive, and the information transmission efficiency of the supply chain information ecological chain. Boehmke and Hazen (2017) proposed to build a supply chain information ecosystem through an open source ecosystem.

It can be seen from the above literature that the study on the balance of the supply chain information ecosystem is still insufficient. Based on the above-mentioned literature, this paper intends to use the system dynamics to establish a mathematical model. Through numerical simulation, it also analyses the impact of information amount, information dissemination speed, information decomposition speed, and information quality etc. on the supply chain revenue in the supply chain ecosystem, and then discusses the related issues such as the balance of the supply chain information ecosystem etc.

The total amount of information in the supply chain information ecosystem changes with time. It’s influenced by factors such as the number of nodes, the willingness to share information, and the speed of information decomposition etc. The more the number of nodes and the greater the willingness to share node information, the higher the information production rate. The information production rate and the information decomposition rate together determine the change in the total amount of supply chain information:

$d m / d t=k_{1} w x-v_{d}$        (1)

where, $m$ is the total amount of information in the supply chain information ecosystem, $w$ is the willingness to share information in general, $v_{d}$ is the speed of information decomposition, $k_{1}$ is the total amount of unique information resources that all nodes can share, and indicating the participation in information sharing in the supply chain ecosystem, and $x$ is the proportion of nodes (for information sharing) in the total number of nodes in the supply chain ecosystem.

In formula (1), the information decomposition speed is a relatively stable value. In this paper, it is assumed to be a constant, and the information sharing willingness is affected by many factors such as the information processing cost in the information sharing process. It is a time-related parameter.:

$d w / d t=\beta-p$           (2)

where, p is the information processing cost, and β is the tolerance degree of the enterprise to the information processing cost. When the information processing cost p exceeds the tolerance threshold β, the willingness to share information will decrease.

The dissemination of information between supply chain nodes depends on the information ecological network. The information dissemination speed is affected by the network topology. In a regular linear network, the information dissemination of two nodes needs to pass through several intermediate nodes at a lower speed of information dissemination; conversely, in a fully connected network the information is transmitted at a relatively faster rate. Since the topology is relatively stable during the evolution of the supply chain ecosystem, in this paper, the constant c was used to describe the impact of topology structure on information propagation speed. The larger value c means that the higher information propagation speed in the network. The amount of information contact within the unit time in the supply chain information ecosystem is proportional to the total amount of information and the speed of information dissemination, namely:

$e=c m$           (3)

where, e is the total amount of information exposed to the node within the unit time.

The higher the speed of information dissemination in the network, the higher the information timeliness and the greater the unit value of information; the stronger the willingness to share information in the information ecosystem, the greater the value of information units. Information decomposition will also increase the quality of information to a certain extent. If the unit value (information quality) of information is u, then:

$u=k_{2} c w v_{d}$            (4)

where, the coefficient $k_{2}$ is the action intensity of the information dissemination speed, the willingness to share, the information decomposition speed and other factors on the value of the information unit.

In the case that the amount of information required by the information user is constant, the more information that is contacted, the greater the probability of obtaining useful information, but the higher the cost of the corresponding information processing; the cost of information processing is proportional to the total amount of information exposure, and inversely proportional to the quality of information:

$p=k_{3} e / u$        (5)

$k_{3}$ is a constant, indicating the action intensity of information exposures within the unit time, and information unit value etc. on the information processing cost.

The income of node is positively correlated with the amount of information and information quality that it is exposed to, but when the amount of information obtained is closer to the actual information demand, the increase of incomes in node is smaller than the amount of information it’s exposed to. In this paper, the logarithmic function was used to describe the phenomenon that the information income decreases with the increase of information quantity and information quality. Assuming that the information income is represented by the symbol

$h=\log \left(1+k_{4} e u\right)$         (6)

where, $k_{4}$

The net income $\pi$

$\pi=h-p$        (7)

Based on formula (1)-(5), the evolved dynamic equation of supply chain information ecosystem is given as:

$\left\{\begin{array}{l}{\frac{d m}{d t}=k_{1} w x-v_{d}} \\ {\frac{d w}{d t}=\beta-k_{3} m /\left(k_{2} w v_{d}\right)}\end{array}\right.$            (8)

By formula (4)-(7), it’s calculated as:

$\pi=\log \left(1+k_{2} k_{4} c^{2} m w v_{d}\right)-\frac{k_{3} m}{k_{2} w v_{d}}$          (9)

Given a set of initial values and parameter values, the total amount of information and the willingness to share information can be obtained according to formula (8). On this basis, the change rule of nodes incomes in the supply chain information ecosystem can be obtained according to formula (9).

From the above analysis, the balance of the supply chain ecosystem shall affect the total revenue of the supply chain. When the amount of information in the system is larger, despite the higher probability that the information user acquires useful information, the relevant information processing cost is higher. Excessive amount of information can also cause a decline in the quality of information, which in turn has a negative impact on supply chain revenue. In order to maintain the balance of the supply chain ecosystem, more emphasis should be put on the role of information decomposition, which can strengthen the function of information decomposers for quickly deleting useless and inaccurate information and then ensure the normal operation of the information ecosystem.

In addition, the speed of information dissemination will have a greater impact on the revenue of the supply chain. At a lower speed of information dissemination, it is difficult for information users to obtain timely information, and the use value of the information will decrease. To ensure the speed of information dissemination in the ecosystem, the topology structure of the supply chain network should be optimized to avoid the generation of linear structures. By controlling the amount of information, enhancing the quality of information, and accelerating the speed of information dissemination, the balance of the supply chain ecosystem can be maintained and then the overall benefits of the supply chain can be promoted.