抄録
Uncertainties in systems engineering are discussed from a viewpoint of fuzzy theory. It is emphasized that the existence of a man plays an essential role in systems engineering and so fuzziness characterizing a man is a key problem to be dealt with. An idea of fuzzy control is introduced as a typical example where fuzzy logic is applied. In order to show wider applicability of fuzzy theory than probability theory, modal classification of uncertainties is made, and some fields of applying fuzzy theory are shown according to the modalities of uncertainties.
