应用实物期权方法研究完全竞争市场环境下的供应链管理中的能力决策问题。通过对能力投资决策的价值分析，给出柔性条件下的能力决策规则，并研究了市场演进的性质、投资成本和缺货成本对决策的影响。结果表明：风险较大(小)的市场、较高(低)的能力投资成本和较低(高)的缺货成本将使得供应链管理者推迟(提前)其扩大能力决策的实施。This paper applies the real-option approach to study the capacity decision in supply chain management under perfect competitive markets. Through analyzing the value of capacity investment decision, we give some rules of the capacity decision with flexibility. We also analyze the influence of three main factors upon the investment decision, which include the property of market evolvement, investment cost, and out of stock cost. The results show that a more (less) risky market, a higher (lower) capacity investment cost, or a lower (higher) out of stock cost is likely to postpone (advance) the implementing of capacity expansion.