从限定可靠性投资的局部与完全经济效益入手，运用实例和经济学理论，论证了在通常情况下，可靠性投资的局部与完全经济效益是统一的这一结论，并从企业投资后产品价格和销量变化的角度，给出可靠性投资的局部与完全经济效益统一的条件。

Partial and full economic benefit from investment in reliability are defined,and the idea that the partial and full economic benefit is unification is discussed by means of examples and economic theory. In vies of the variation in price ad sales volume after reliability investment, the unified condition of the partial and full economic benefit are given in this paper.