This paper indicates deficiencies of existing weighting methods for decision problems that require trading off a selection of one alternative against others. Deficiencies originate from the definition of weight, $W_i$, satisfying that $W_i{geq}0$ for all i and sums up to one and an assumption of independence between attributes. Thus, existing weighting methods can not handle a situation where all attributes are interrelated, resulting in that attributes can give either positive, or negative, contributions to the value of an alternative. In order to cope with deficiencies, this paper redefines weight and proposes a new causally related weighting method. The proposed method was applied in the study of developing a comprehensive organizational performance measurement system and showed a good performance.