中文摘要：

运用有向二部图和随机过程的方法，基于多供应商和多需求商供应链，综合考虑了时间及内外因素的影响，在供应商和需求商身份惟一确定的情形下建立了一个可靠性随机模型。通过对模型的讨论，给出了计算供应商和需求商失效概率的统一表达式，并将模型推广到供应商和需求商身份非惟一的情形。

英文摘要：

Through directed bipartite graph and the method of stochastic process, based on the supply chain for many suppliers and demanders, a reliable stochastic model is set up under the comprehensive consideration of the effects of time as well as internal and external factors, meanwhile, the case of the unique identity of suppliers and demanders is also confirmed. Moreover, through the discussion of the model, a unified formula for calculating the failure probability of the suppliers and demanders is also given, and the model is popularized in other cases, namely, when the identity of suppliers and demanders is not uniquely confirmed.