1. A factor analysis system, comprising: a data receiving module receiving a plurality of factors that have influence on a target total value, a plurality of base values corresponding to the factors, and a target improvement percentage; the factors comprising a first factor and a second factor, the base values comprising a first base value for the first factor and a second base value for the second factor, and the target improvement percentage comprising a first factor improvement in percentage point and a second factor improvement in percentage point; a first computing unit being connected to the data receiving module; the first computing unit using the base values of the factors as a basis to compute a reference target total value, and using the first factor increased by one percentage point and the second base value of the second factor as a basis to compute a first upgraded target total value, and using the second factor increased by one percentage point and the first base value of the first factor as a basis to compute a second upgraded target total value; a second computing unit being connected to the first computing unit; the second computing unit using the first upgraded target total value and the reference target total value as a basis to compute a first factor sensitivity, and using the second upgraded target total value and the reference target total value as a basis to compute a second factor sensitivity; and a processing module being connected to the second computing unit and the data receiving module; the processing module multiplying the first factor improvement by the first factor sensitivity to obtain a first factor contribution indicating a level of contribution of the first factor to the target total value, and multiplying the second factor improvement by the second factor sensitivity to obtain a second factor contribution indicating a level of contribution of the second factor to the target total value.