Patent Number: 
Section: claims

1. 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; andinfluence 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. 2. The factor estimating device of claim 1 further comprising aimed node determining means for determining as an aimed node, when data obtained by said item data obtaining means satisfy a condition, the node to which said satisfied condition branches;said item data obtaining means obtaining data of an input item selected out of those of input items corresponding to said aimed node and nodes on the downstream side of said aimed node by considering the influence factors. 3. The factor estimating device of claim 2 wherein said aimed node determining means determines an earlier determined aimed node as the aimed node if there is no input item with influence factor higher than a specified value. 4. The factor estimating device of claim 1 further comprising a related item recording part for grouping and recording data on a plurality of related input items;wherein said item data obtaining means obtains not only data on a selected input item by considering the influence factors but also data on input items that belong to same group as said selected input item. 5. The factor estimating device of claim 4 further comprising a related item recording part for grouping and recording data on a plurality of related input items;said item data obtaining means obtaining not only data on said selected input item by considering the influence factors but also data on input items that belong to same group as said selected input item and have influence factors higher than a specified value. 6. The factor estimating device of claim 1 further comprising input control means for obtaining a user's response to a question corresponding to a condition contained in said factor estimating knowledge data;wherein said item data obtaining means obtains said data on said input item based on said response obtained by said input control means. 7. The factor estimating device of claim 6 further comprising:inspection result inputting means for receiving inspection result data from an inspection device that inspects said target system;an inspection result recording part that records said inspection result data received by said inspection result inputting means; andan obtaining method recording part for recording data on an obtaining method indicating whether said data on said input item are obtained either from a user or from said inspection result data or from both said user and said inspection result, as well as said data on said input item;wherein said item data obtaining means obtains said data on said input item based on said data on the obtaining method corresponding to said input item. 8. The factor estimating device of claim 1 that estimates a factor from a no-good result generated in a processing system which carries out processes on a target object. 9. A program storage device readable by a machine, tangibly embodying a program of instructions executable by said machine to a factor estimating device for estimating a factor from a result generated in a target system of 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; andinfluence 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 related 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. 10. The program storage device of claim 9 wherein said factor estimating device further comprises aimed node determining means for determining as an aimed node, when data obtained by said item data obtaining means satisfy a condition, the node to which said satisfied condition branches;said item data obtaining means obtaining data of an input item selected out of those of input items corresponding to said aimed node and nodes on the downstream side of said aimed node by considering the influence factors. 11. The program storage device of claim 10 wherein said aimed node determining means determines an earlier determined aimed node as the aimed node if there is no input item with influence factor higher than a specified value. 12. The program storage device of claim 9 wherein said factor estimating device further comprises a related item recording part for grouping and recording data on a plurality of related input items;wherein said item data obtaining means obtains not only data on a selected input item by considering the influence factors but also data on input items that belong to same group as said selected input item. 13. The program storage device of claim 12 wherein said factor estimating device further comprises a related item recording part for grouping and recording data on a plurality of related input items;said item data obtaining means obtaining not only data on a selected input item by considering the influence factors but also data on input items that belong to same group as said selected input item and have influence factors higher than a specified value. 14. The program storage device of claim 9 wherein said factor estimating device further comprises input control means for obtaining a user's response to a question corresponding to a condition contained in said factor estimating knowledge data;wherein said item data obtaining means obtains said data on said input item based on said response obtained by said input control means. 15. The program storage device of claim 14 wherein said factor estimating device further comprises:inspection result inputting means for receiving inspection result data from an inspection device that inspects said target system;an inspection result recording part that records said inspection result data received by said inspection result inputting means; andan obtaining method recording part for recording data on an obtaining method indicating whether said data on said input item are obtained either from a user or from said inspection result data or from both said user and said inspection result, as well as said data on said input item;wherein said item data obtaining means obtains said data on said input item based on said data on the obtaining method corresponding to said input item. 16. The program storage device of claim 9 wherein said factor estimating device estimates a factor from a no-good result generated in a processing system which carries out processes on a target object. 17. A method of estimating a factor by a factor estimating device for estimating a factor from a result generated in a target system for diagnosis, said factor estimating device being provided with 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, said method comprising:an inference step of carrying out factor estimating process based on said factor estimating knowledge data recorded in said estimate knowledge recording part;an item data obtaining step of obtaining data on input item corresponding to conditions contained in said factor estimating knowledge data during said factor estimating process in said inference step;a fitness calculating step of calculating fitness factors based on the data obtained in said item data obtaining step, said fitness factors being indicative of degrees to which said conditions are satisfied;a certainty calculating step of 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; andan influence calculating step of 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.