A Numeric PDDL Based Approach for Temporally Constrained Journey Problems

Many realistic life scenarios require dealing with deadlines and action durations. Such constraints, together with propositional and resource conditions must be taken into account in order to make plans which are actually feasible. In order to combine these aspects, the paper deals with the entailed temporal constrained planning problem by using the framework of numeric planning, based on an action centred philosophy a-la PDDL. The approach is motivated by the necessity of integrating scheduling and planning in the context of a multi-modal journey planning problem. In order to evaluate the feasibility of the approach, the paper presents JoPA, a web service architecture which has been thoroughly evaluated employing two state of the art numeric planning systems, i.e. Metric-FF and Colin. Results show that the approach is feasible considering (un)constrained and optimization tasks.