JOEL M. CRICHLOW, Ph.D., is Associate Professor of Computer Science at Rowan University, Glassboro, New Jersey (U.S.A.). He did his doctorate in Mathematics from the University of the West Indies in 1983. He has more than 30 years of teaching experience in Computer Science and Mathematics. Dr. Crichlow has authored three books on Distributed Systems and a number of research papers. His current research concentrates on concurrency and replica management issues in distributed systems.