Research on Supply Chain Risk Transmission Mechanism Based on Improved SIRS Model

Table 1

Variables and parameter definitions used in the model.

Symbols	Definitions	Implications for supply chain networks
s(t)	Percentage of individuals in a susceptible state at time t to the total number of individuals	Percentage of the number of enterprises with the possibility of infection risk at time t to the total number of enterprises
i(t)	Percentage of individuals in an infected state at time t to the total number of individuals	Percentage of the number of enterprises exposed to risk at time t to the total number of enterprises
r(t)	Percentage of individuals in an immune state at time t to the total number of individuals	Percentage of the number of enterprises with immunity to risk at time t to the total number of enterprises
d(t)	Percentage of individuals in an eliminated state at time t to the total number of individuals	Percentage of the number of enterprises eliminated for failure to withstand risk at time t to the total number of enterprises
Β	Probability of infection	Probability of infection risk
γ	Probability of immunity	Probability of immunity to risk
Δ	Probability of losing immunity	Probability of losing immunity to risk
μ	Probability of being eliminated	Probability of being eliminated
<k>	Network average degree