Patent ID: 7310591

Claim:
A factor estimating device for estimating a factor from a result generated in a target system for diagnosis, said factor estimating device comprising; an estimate knowledge recording part for recording factor estimating knowledge data that correlate one or more candidates for factor to each of a plurality of results that may be generated in said target system and show factor estimating paths from each of said results to each of said candidates corresponding to said each result as knowledge of a network structure having condition branches; inference processing means for carrying out factor estimating process based on said factor estimating knowledge data recorded in said estimate knowledge recording part; item data obtaining means for obtaining data on input item corresponding to conditions contained in said factor estimating knowledge data while said inference processing means carries out said factor estimating process; fitness calculating means for calculating fitness factors based on the data obtained by said item data obtaining means, said fitness factors being indicative of degrees to which said conditions are satisfied; certainty calculating means for calculating for each of the factors a representative value of an assembly of fitness factors corresponding to a condition contained in said factor estimating paths as certainty factor; and influence calculating means for calculating influence factor for each of input items indicative of degree of influence on the certainty factor when said data on said input item are obtained regarding a certain input item; wherein said item data obtaining means obtains data on a selected input item by considering the influence factors.