Capacity-filtering algorithms for finite-capacity planning of a flexible flow line

Abstract

This paper addresses finite-capacity planning (or medium-term scheduling) issues in a flexible flow line such as a semiconductor fabrication (Fab), liquid crystal display (LCD) Fab, or printed circuit board (PCB) Fab. In such a flexible flow line, medium-term schedules such as release schedules and output schedules are critical to achieving the goal of full-capacity and on-time production. However, existing finite-capacity planning methods do not adequately reflect the actual capacity profiles of the Fab. This paper presents capacity-filtering algorithms for generating a finite-capacity loading-profile from an infinite-capacity loadingprofile at a processing stage in a Fab. In addition, two types of finite-capacity planning problems are described, and ways to use the algorithms in solving these problems presented. Performance analyses using a real-life case study show that the proposed method is superior to existing methods. It is postulated that the results presented can be used as a building block for obtaining medium-term schedules for the entire Fab.