Research in semiconductor manufacturing ideally wants to determine the “best” transport policy to ensure continuous production. Determining such a policy is difficult because it depends on many factors such as the layout, the product types, the equipment, etc. Most of the transport policies found in the literature combine dispatching policies (scheduling of transport requests) and routing policies (selection of the path to move from one point to another). This paper investigates a policy called "minimum service" which consists in keeping a minimum number of available vehicles in bays, so that they can quickly answer transport requests and empty travel times can be minimized. This paper aims at comparing, through experimental tests on actual instances of a real semiconductor manufacturing facility, two types of transport policies in terms of cycle time, throughput and Carrier Exchange Time. Moreover, the behavior of the “minimum service” policy is studied when the number of vehicles and the number of starting lots are varied. The results show that the “minimum service” policy is in general more effective than a classical policy, but that its key parameters must carefully be determined.
Progress in Material Handling Research: 2010
Kiba, J. E.; Dauzère-Pérès, S.; Yugma, C.; and Lamiable, G., "Comparing Transport Policies in a Full-scale 300mm Wafer Manufacturing Facility" (2010). 11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010). 33.