A computer system which a i d s computer e n g i n eers i n f a u l t d i a g n o s i s i s d e s c r i b e d . The sys tem, c a l l e d CRIB (Computer R e t r i e v a l I nc idence Bank) i s shown t o f i t i n t o the c l a s s o f p a t t e r n d i r e c t e d i n f e r e n c e sys tems. Emphasis is p laced on the " b e f o r e " and " a f t e r " phases o f system g e n e r a t i o n and i ...