Affiliations: Delft University of Technology, P.O.Box 5031, 2600 GA
Delft, The Netherlands. E-mail: {r.p.j.vanderkrogt, m.m.deweerdt,
c.witteveen}@ewi.tudelft.nl
Abstract: The aim of this paper is to combine standard planning and replanning
methods into a rigorous unifying framework, extending an existing logic-based
approach to resource-based planning. In this Action Resource Framework (ARF),
actions and resources are the primitive concepts. Actions consume and produce
resources. Plans are structured objects composed of actions and resource
schemes and an explicit dependency function specifying their
interrelationships. Previous plans can be used both for creating new plans and for
modifying plans. Since we are often interested in reusing only a part of these
previous plans, we extend the Action Resource Formalism with incomplete
plans. To efficiently represent such incomplete plans we use the notion of a
gap. We maintain a library of incomplete plans (with gaps), and we
present operators to insert plan parts from this plan library into the current
plan. We prove this set of plan operators to be complete. Generalizing the refinement planning approach, we present a template
algorithm for both planning and replanning using the ARF and its plan library
and plan operators. Finally, we show that existing (re)planning methods and
heuristics nicely fit into this framework.