A method and system for determining a variable compensation amount according to the degree of achievement by avoiding stop at the stage where value brought about to a client by a solution is qualitatively evaluated, avoiding compensation calculation from being performed by accumulation of cost such as labor cost, and quantitatively estimating the effect from the viewpoint of a set KPI in consideration of risk to achievement of the KPI. There is provided a system for supporting advance evaluation of a service for improving business, comprising: input means for accepting selection of an index indicating the degree of improvement of the business and accepting setting of multiple future scenarios which influences success/failure of the improvement of the business; storage means for storing the index and the multiple scenarios; and calculation means for calculating a primary estimate value of the index in the case of occurrence of each scenario and calculating a secondary estimate value based on the primary estimate value and a primary risk corresponding to the primary estimate value.