Once you know the selling price and direct costs of each product or service unit you sell, you can calculate your contribution margin in dollars per unit. 也就是超出直接成本的部分(你可以把单位设定为一个产品或者一小时的服务)。
Analysis on how to influence the standard deviation coefficient by utilizing the unit contribution margin 单位毛利对标准差系数影响的分析
But the unit contribution margin is at a lower level, it will appear the unusual case. 但是单位毛利降低时,就会出现异常的情况。