抄録
It is of utmost importance that systems maintain the robustness in itself to reduce the influence of the uncertain factors resulting from the various external conditions on the reliability of systems. This private view proposes the diversity of elements composing systems as one of the robustness in systems and discusses the fundamental issues related to the diversity from the two viewpoints of probabilistic theory and information theory. It is hoped that such a private view will help to maintain the robustness in systems.
