**About the Editors**

**Panagiotis-Christos Vassiliou** is an Honorary Professor at the Department of Statistical Sciences, University College London and an Emeritus Professor at the Department of Mathematics, Aristotle University of Thessaloniki. He has spent research and teaching time at Ulster University, Ioannina University, Aristotle University of Thessaloniki, University College London. He has also spent research time at Imperial College London. He taught at the London Taught Course Center (LTCC), for 3rd and 4th year Ph.D. students of UCL, LSE, King's, Brunel and Kent. He has published more than 53 papers, which are indexed in the web of science, mainly in the areas of non-homogeneous Markov systems, non-homogeneous semi-Markov systems, and stochastic finance. His publication timespan is 47 years and the two journals with the highest frequency were Journal of Applied Probability and Linear Algebra and its Applications. He has also written four books in English (J. Wiley, Chapman and Hall, UCL, MDPI) and 13 books in Greek. He has supervised nine completed PhD theses and Refereed more than 25 scientific journals.

**Andreas C. Georgiou** is a Professor of Operational Research and Director of the Quantitative Methods and Decision Analytics Lab at the Department of Business Administration of the University of Macedonia. Formerly Director of the MBA program and of the MSc in Business Analytics and Data Science. His research includes Markov Processes, manpower planning, Business Analytics applications in operations, DES, MCDM, AHP and DEA. He teaches undergraduate and postgraduate courses at the Aristotle University of Thessaloniki, University of Macedonia and the Greek Open University. He is a member of several International Societies such as INFORMS and OR Society. His publications include more than 80 papers in international conferences proceedings and top-tier journals. He has also co-authored several textbooks in Greek, served as a reviewer for more than 50 International Journals and has more than 850 citations to his work.
