试论中间试验的规模选择与投资决策条件

A Study on the Selection for Pilot-testing Scale and the Requirement for Investment

科技成果的风险性随中试规模大小呈现一定的变化规律。中试临界规模就是成果的风险性由高速向低速转变时所对应的中试规模。根据中试规模贡献曲线的特性，给出了中试临界规模点的数学表达式：ｄＲｄＳ｜ｓ＜＝ＳｏｄＲｄＳ｜ｓ＞Ｓｏ和Ｓｏ＝Ｒ－１（Ｒｏ）。选择中试最佳规模必须同时考虑中试规模贡献和中试成本。结合中试规模贡献曲线Ｒ（Ｓ）和中试成本曲线Ｃ（Ｓ），中试最佳规模点便是Ｔ（Ｓ）＝Ｃ（Ｓ）＋Ｒ（Ｓ）中总成本达到最小时所对应的点，其导数表达式为ｄＴｄＳ｜ｓ＝Ｓ′＝０。“是否中试”还要比较最佳规模点时中试成本与中试规模贡献之间的大小，从而得到中间试验的投资决策条件为Ｒｃ－Ｒ（Ｓ′）＞＝Ｃ（Ｓ′）。

The risk of scientific and technological achievements varys in a regular pattern with the change of pilot-testing scale.The critical scale of pilot-testing is the very point at which the risk of achievements grows from high to low.According to the characteristic curve of pilot-testing scale contribution, two expressions,dRdS|s<=SodRdS|s>So and So=R -1 (Ro),for the critical point of pilot-testing scale are given. Furthermore, selecting the optimal pilot-testing scale depends on both pilot-testing contribution and pilot-testing cost. Based on the curve of pilot-testing scale contribution,R(S),and the curve of pilot-testing cost, C(S), the optimal pilot-testing scale is the very point at which the curve of total cost, T(S)=C(S)+R(S), reaches a minimum and its derivative expression is dTdS|s=S=0, Whether have a practical pilot-testing or not still relys on the puantitative difference between pilot-testing cost and pilot-testing scale contribution ,thus the repuiement for pilot-testing investment ,Rc-R(S′)>=C(S′) is decided.