Herry Nugraha PT PLN (Persero) Jl. Trunojoyo Blok M-I No. 135. Kebayoran Baru, Jakarta 12160, Indonesia e-mail: herry.nugraha@gmail.com He received the Mechanical Engineering degree and Electrical Master degree from Bandung Institute of Technology, Indonesia, in 1993 and 2010, respectively. He also received Doctor degree from the School of Electrical Engineering and Informatics Bandung Institute of Technology, Indonesia in 2016. He works for PLN. His research interests include operation and maintenance engineering of power system, economics of electric energy systems, Asset Management, as well as statistics and optimization theory and its applications and risk analysis.