Mangey Ram received his Ph.D. degree major in Mathematics and minor in Computer Science from G. B. Pant University of Agriculture and Technology, Pantnagar, India, in 2008. He is currently a Professor at Graphic Era (Deemed to be University), Dehradun, India. He is Editor-in-Chief of International Journal of Mathematical, Engineering and Management Sciences and an editorial board member of several international journals. His fields of research are Operations Research, Reliability Theory, Fuzzy Reliability and Systems Engineering. Tadashi Dohi received his Bachelor, Master and Doctor of Engineering degrees from Hiroshima University, Japan, in 1989, 1991 and 1995, respectively. He is currently the Vice Dean of the School of Informatics and Data Science, Hiroshima University. His research areas include Reliability Engineering, Software Reliability, Dependable Computing, Performance Evaluation, Computer Security and Operations Research. He is also the President of the Reliability Engineering Association of Japan (REAJ).