FLECS: Planning with a Flexible Commitment Strategy

TL;DR

FLECS is a flexible planning algorithm that dynamically chooses between eager and delayed commitment strategies, optimizing planning efficiency across various domains and problem types.

Contribution

Introduces FLECS, a novel planner that adaptively switches between commitment strategies, enabling analysis of strategy effectiveness per domain and problem.

Findings

FLECS outperforms fixed-strategy planners in diverse domains.

It effectively adapts its commitment approach during planning.

FLECS provides insights into strategy-domain mappings.

Abstract

There has been evidence that least-commitment planners can efficiently handle planning problems that involve difficult goal interactions. This evidence has led to the common belief that delayed-commitment is the "best" possible planning strategy. However, we recently found evidence that eager-commitment planners can handle a variety of planning problems more efficiently, in particular those with difficult operator choices. Resigned to the futility of trying to find a universally successful planning strategy, we devised a planner that can be used to study which domains and problems are best for which planning strategies. In this article we introduce this new planning algorithm, FLECS, which uses a FLExible Commitment Strategy with respect to plan-step orderings. It is able to use any strategy from delayed-commitment to eager-commitment. The combination of delayed and eager operator-ordering commitments allows FLECS to take advantage of the benefits of explicitly using a simulated execution state and reasoning about planning constraints. FLECS can vary its commitment strategy across different problems and domains, and also during the course of a single planning problem. FLECS represents a novel contribution to planning in that it explicitly provides the choice of which commitment strategy to use while planning. FLECS provides a framework to investigate the mapping from planning domains and problems to efficient planning strategies.