Plan Optimization by Plan Rewriting

Planning by Rewriting (PbR) is a paradigm for e‐cient high-quality planning that exploits declarative plan rewriting rules and e‐cient local search techniques to transform an easy-to-generate, but possibly suboptimal, initial plan into a high-quality plan. In addition to addressing planning e‐ciency and plan quality, PbR ofiers a new anytime planning algorithm. The plan rewriting rules can be either specifled by a domain expert or automatically learned. We describe a learning approach based on comparing initial and optimal plans that produces rules competitive with manually-specifled ones. PbR is fully implemented and has been applied to several existing domains. The experimental results show that the PbR approach provides signiflcant savings in planning efiort while generating high-quality plans.