The present invention relates to a computer-implemented fraud method and system for managing fraud screening in response to a requested transaction. The fraud management system checks the efficiency of the fraud screening strategy and predicts the efficiency of new fraud screening strategies based on the total cost of fraud. This calculation is facilitated, because transactions are divided into groups, and the total cost of fraud may be calculated for a representative element of the group, and not for each transaction in the group. Furthermore, if the fraud screening is based on rules that apply an acceptance flow to predetermined conditions, the fraud management can choose the best acceptance flow for these predetermined conditions by minimizing the total cost of fraud. Finally, the fraud management can also flag inefficient rules thanks to an indicator related to the total cost of fraud to highlight rules whose predetermined conditions should be changed.