This paper briefly reviews sources of symmetry in planning and highlights one source that has not previously been tackled: plan permutation symmetry. Symmetries can be a significant problem for efficiency of planning systems, as has been previously observed in the treatment of other forms of symmetry in planning problems. We examine how plan permutation symmetries can be eliminated and present ...

Die flexible Produktionsfeinplanung mithilfe von Planungsschritten ist ein anwendungsabhängiger Planungsansatz für die Produktionsplanung und -steuerung. Grundlage der Planungsansatzes sind Planungsschritte mit Voraussetzungen und Konsequenzen. Ein Plan besteht aus einer endlichen halbgeordneten Menge partiell initialisierter Planungsschritte zum Erreichen eines Ziels, ausgehend von einer anfän...

Plan library's have proven their added value to the e ciency of planning. In this paper, we present results on the use of a plan library to plan repair. We show that using a relatively simple library, we can already obtain signi cant improvements in e ciency compared to plan repair without a library.

The sequence of mating operations which can be carried out to assemble a group of parts is constrained by the geometric and mechanical properties of the parts, their assembled configuration, and the stability of the resulting subassemblies. An approach to representation and reasoning about these sequences is described here, and leads to several alternative explicit and implicit plan representat...