Abstract: Basing on the property of supply-chain networks, this paper proposes a randomly growing directional model whose node-arrival process is a renewal process and the number of new edges is a random variable with Bernoulli distribution. We calculate the degree distributions and stationary average degree distributions of the network model by using the renewal process theory and the continuum theory. The paper shows that the supply chain networks have bilateral power-law distributions.

Keywords: 
• complex network /
• in-degree /
• out-degree /
• degree distribution