Arnold O. Allen is a member of the technical staff of the Performance Technology Center at Hewlett-Packard. He received his Ph.D. in mathematics from UCLA. Much of the material in the book was developed for classes in probability, statistics, queueing theory, and computer modeling that he taught as UCLA, IBM, and Hewlett-Packard. Dr. Allen has been active in teaching conference tutorials on computer modeling and was the keynote speaker at two international conferences.