13 research outputs found
Creation of the selection list for the Experiment Scheduling Program (ESP)
The efforts to develop a procedure to construct selection groups to augment the Experiment Scheduling Program (ESP) are summarized. Included is a User's Guide and a sample scenario to guide in the use of the software system that implements the developed procedures
Fill-Rate Optimization in a One-Warehouse N-Identical Retailer Distribution System
This paper examines the system fill-rate of a one-warehouse N-identical retailer distribution system as a function of warehouse and retailer safety stock. Using the approximation model of Deuermeyer and Schwarz (Deuermeyer, B. L., L. B. Schwarz. 1981. A model for the analysis of system service level in warehouse/retailer distribution systems: the identical retailer case. Chapter 8 in Multi-Level Production/Inventory Control Systems: Theory and Practice. North-Holland, Amsterdam.) we examine the problem of maximizing system fill-rate subject to a constraint on system safety stock. Optimal safety stock policy is characterized to be the intersection of a fill-rate policy line and the safety stock budget line. Properties of fill-rate policy lines are given. These properties may be used to provide managerial insight into system optimization and as the basis for heuristics. One heuristic, the vertical heuristic, based on the corresponding deterministic version of the problem, yields trivially simple and near-optimal policies.inventory/production, multi-echelon inventory system, fill-rate optimization
Max-min Online Allocations with a Reordering Puffer
We consider a scheduling problem where each job is controlled by a selfish agent, who is only interested in minimizing its own cost, which is defined as the total load on the machine that its job is assigned to. We consider the objective of maximizing the minimum load (cover) over the machines. Unlike the regular makespan minimization problem, which was extensively studied in a game theoretic context, this problem has not been considered in this setting before. We study the price of anarchy (\poa) and the price of stability (\pos). Since these measures are unbounded already for two uniformly related machines, we focus on identical machines. We show that the \pos is 1, and we derive tight bounds on the \poa for and nearly tight bounds for general . In particular, we show that the \poa is at least 1.691 for larger and at most 1.7. Hence, surprisingly, the \poa is less than the \poa for the makespan problem, which is 2. To achieve the upper bound of 1.7, we make an unusual use of weighting functions. Finally, in contrast we show that the mixed \poa grows exponentially with for this problem, although it is only for the makespan. In addition we consider a similar setting with a different objective which is minimizing the maximum ratio between the loads of any pair of machines in the schedule. We show that under this objective for general the \pos is 1, and the \poa is 2