I joined the RAND Corporation in June of 1954 after receiving my Ph.D. in Mathematics from Princeton University. One of my reasons for choosing RAND rather than a more conventional academic appointment was my desire to be involved in applied rather than abstract mathematics. I could not have selected a better location to achieve this particular goal. George Dantzig had arrived recently and was in the process of applying linear programming techniques to a growing body of basic problems. Richard Bellman was convinced that all optimization problems with a dynamic structure (and many others) could be formulated fruitfully, and solved, as dynamic programs. Ray Fulkerson and Lester Ford were working on network flow problems, a topic which became the springboard for the fertile field of combinatorial optimization. Dantzig and Fulkerson studied the Traveling Salesman problem and other early examples of what ultimately became known, under the guidance of Ralph Gomory, as integer programming. In 1955 the organization was visited by a budgetary crisis and I was asked if I would mind taking up temporary residence in the Department of Logistics. The Logistics Department was a junior subgroup of the Department of Economics at RAND, with a much more prosaic mission than that of its senior colleagues. The members of the Logistics Department were concerned with scheduling, maintenance, repair and inventory management, and not with the deeper economic and strategic questions of the Cold War. Andy Clark was in the department, and we may have met each other casually but we certainly didn’t do any work together, and we probably never had a serious conversation about research while we were both at RAND. Later in these notes I will describe our collaboration on the multiechelon inventory problem in the spring of 1959. Since that time, some