Planning under resource constraints

This paper outlines the basic principles underlying reasoning about resources in IPP, which is a classical planner based on planning graphs originally introduced with the GRAPHPLAN system. The main idea is to deal with resources in a strictly action-centered way, i.e., one specifies how each action consumes or produces resources, but no explicit temporal model is used. This avoids the computational problems of solving general constraint satisfaction problems by using instead interval arithmetics and propagation of resource requirements over time steps in the planning graph.