Article ID: | iaor2004102 |
Country: | United States |
Volume: | 50 |
Issue: | 2 |
Start Page Number: | 167 |
End Page Number: | 183 |
Publication Date: | Mar 2003 |
Journal: | Naval Research Logistics |
Authors: | Ryan Sarah M. |
Keywords: | programming: dynamic, facilities |
The combination of uncertain demand and lead times for installing capacity creates the risk of shortage during the lead time, which may have serious consequences for a service provider. This paper analyzes a model of capacity expansion with autocorrelated random demand and a fixed lead time for adding capacity. To provide a specified level of service, a discrete time expansion timing policy uses a forecast error-adjusted minimum threshold level of excess capacity position to trigger an expansion. Under this timing policy, the expansion cost can be minimized by solving a deterministic dynamic program. We study the effects of demand characteristics and the lead time length on the capacity threshold. Autocorrelation acts similarly to randomness in hastening expansions but has a smaller impact, especially when lead times are short. However, the failure either to recognize autocorrelation or to accurately estimate its extent can cause substantial policy errors.