Here, the correlations between the identified attributes can be found by determining whether there exist correlated attributes between attributes related with the problem. In case a plurality of attributes need to be applied at the same or different time in order to solve the problem, it can be defined that these plurality of attributes are correlated with one another. Further, in case a plurality of attributes need to be applied at the same or different time in order to create the problem, it can be defined that these plurality of attributes are correlated with one another. Therefore, according to the method for the present embodiment, the analysis can be conducted not only by using the attributes, but also by using the correlations between the attributes, which leads to a more precise analysis result.

For example, with reference to FIG. 3, it can be identified that the first attribute and the second attribute are correlated with each other, with regard to the first problem.

Between identified attributes, a plurality of correlations may be found. In this case, after finding the plurality of correlations between the identified attributes, the characteristic of a problem can be determined by the identified attributes and the plurality of correlations. For example, with reference to FIG. 3, it can be found that there exists correlation between the first attribute and the second attribute, and that these exists correlation between the second attribute and the third attribute.