Kodo Ito received B.S. and M.S. degrees in Physics from Yamagata University, Japan, in 1983 and 1985, respectively, and D.E. degree from Aichi Institute of Technology, Japan, in 1999. He worked as Aircraft Engineer with Mitsubishi Heavy Industries, Ltd., Nagoya, Japan, for 32 years from 1985 to 2017. He is now Professor at Tottori University, Japan, and Visiting Professor at Fukushima University, Japan. His research interests are practical optimal operation and maintenance policies for large and complicated systems such as missile systems, radar systems, aircraft engine controllers, airframes, power plants, and social infrastructures.   Toshio Nakagawa received B.S.E. and M.S. degrees from Nagoya Institute of Technology, Japan, in 1965 and 1967, respectively, and Doctor degree from Kyoto University, Japan, in 1977. He worked as Research Associate at Syracuse University for two years from 1972 to 1973. He is now Honorary Professor at Aichi Institute of Technology, Japan. His research interests are optimization problems in operations research and management science and analysis for stochastic and computer systems in reliability and maintenance theory. He has published 7 books from Springer and more than 300 papers in research journals.