Spartial scheduling and its application to shipbuilding

Abstract

There can be many scheduling problems one of the resources in which is two or three dimensional space. We will call spatial resource scheduling problem ``Spatial Scheduling`` in this thesis. Since spatial scheduling should plan the dynamic spatial layout, the characteristics of the problem are different from those of traditional scheduling problem. Spatial scheduling has two major topics. One is scheduling and the other is spatial layout planning. As a prior phase of research about spatial scheduling, we develop a methodology for spatial allocation of convex polygons in a rectangle. As a representation scheme of the problem, we apply configuration space approach in Find-path problem. Above its foundation, the concept of distinct space is introduced to reduce search space. And given search space reduced, several allocation strategies are developed, compared each other and combinated to increase allocation performance. In two dimensional spatial resource problem, we introduce a three dimensional view of the spatial scheduling. With the three dimensional view of spatial scheduling, we define distinct scheduling space and propose the strategies for searching a solution in the space. The developed methodologies for spatial scheduling are applied to block assembly scheduling in ship building industry. To satisfy the constraints of the factory environment, we adopt a knowledge-based approach and develop a spatial scheduling expert system (DAS-SS) using UNIK-FRAME, UNIK-WINDOW, and LISP languages. Due to computational intractability of spatial scheduling problem, we develop heuristic procedures composed of a myopic optimal scheduling procedure and a backtracking procedure.