JPH0572638B

PURPOSE:To simplify the calculation procedure of each basic probability and to improve the accuracy of diagnosis by calculating a last occurrence probability every each cause item from each basic probability estimating each cause item respectively and independently obtained through matrix processing with the aid of using the associative law of Dempster. CONSTITUTION:The plural kinds of qualitative data 2 and the plural kinds of quantitative data 3 obtained from a system 1 are inputted to a basic probability calculation part 5 through a data input part 4. A matrix data memory storing the relation between the respective qualitative data and the respective cause items in a matrix state and a matrix data memory storing the relation between the respective quantitative data and the respective cause items in a matrix state are formed in a external memory part 6 connected to the calculation part 5. Then the last occurrence probability every cause item is calculated from each basic probability estimating each cause item respectively and independently obtained through the matrix processing by using the associative law of dempster. Thus the calculation procedure of each basic probability can be simplified and the accuracy of the diagnosis can be improved.