A coordinated planning model for the design of a distributed database system

Motivated by a problem faced by a multimedia entertainment retailer, we explore the problem of planning the design of a distributed database system. The problem consists of planning the design/expansion of the distributed database system by introducing new database servers and retiring possibly some existing ones in order to reduce telecommunication costs for processing user queries and server acquisition, operations and maintenance cost in a multiperiod environment where user processing demand varies over time. We develop a mathematical programming model and an effective solution approach to determine the best decisions regarding acquisition and retirement of database servers and assignment of user processing demand to the servers over time. Through a computational study, we investigate the impact of important parameters such as length of the planning horizon and demand growth on the solution quality and utilization of server capacity and examine the effectiveness of the solution approach in comparison with the commercial package LINDO. We also discuss some extensions to the problem as directions for future research. (C) 2003 Elsevier Inc. All rights reserved.