Job Dispatch Control for Production Lines With Overlapped Time Window Constraints

Abstract

Semiconductor manufacturing processes often come with stringent requirements for product quality. In order to satisfy these requirements, time window constraints have been imposed. Typically, violation of the time windows can result in a lot being either reworked or scrapped. The presence of overlapped time window constraints renders the control of production lines very challenging as it involves managing the production process of many lots across multiple workstations. We study the performance of a production line with deterministic service times and predetermined, overlapped time windows. We solve the P|rj|Cmax problem to estimate the queue time at each workstation, and develop an algorithm to decide whether a new lot can be released for processing at its first workstation so as to meet all time window constraints.