Maximizing Delivery Performance in Semiconductor Wafer Fabrication Facilities

This paper is motivated by the problem of scheduling customer orders (jobs) in a semiconductor fabrication facility (“wafer fab”) to maximize delivery performance when the jobs have non-identical priorities (weights). As each job is typically assigned a weight based on its size, value, and/or requesting customer, a wafer fab’s delivery performance can be evaluated in terms of minimizing the sum of each job’s weighted tardiness. A heuristic has been proposed for obtaining “good” solutions to this complex problem. Using a “real world” wafer fab data model, the heuristic is compared to a number of dispatching rules in terms of how well each method produces job sequences that maximize delivery performance of customer orders. Results suggest that the heuristic consistently produces the best overall schedules, but there is a price to be paid in terms of solution speed.