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just some of the arguments that are leading to the progressive exploration of different
planning methodologies and to the extensions of most classic ones.
Timeline based planning constitutes an intuitive alternative to classical planning ap-
proaches by identifying relevant domain components evolving in time. Although attrac-
tive from a temporal flexibility point of view, these kind of planners have to cope with
performance issues due to the complexity that derives from their expressiveness.
In this paper we have proposed an architecture that filters out common elements from
timeline-based planners with the intent to focus the attention to underlying constraint
reasoners that could lead to different possible flaw selection and flaw resolution strate-
gies. In so doing we have discovered the superiority of a particular approach over the
other proposed ones in the context of the given domain. However we are confident that
other approaches can be improved and can possibly outperform the actual results in
different domains.
Some points are still open. The heuristics for flaw selection and flaw resolution
strategies are still relatively poor to compete in performance with state-of-the-art classi-
cal planners. The thrust to classical planning given by G
RAPHPLAN
and the consequent
development of heuristic based search is something that is still missing in the timeline-
based area.
Acknowledgements.
Authors have been partially supported by EU under the PAN-
DORA project (FP7.225387) and by MIUR under the PRIN project 20089M932N.
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