Domain-independent multi-agent plan repair

Achieving joint objectives in distributed domain-independent planning problems by teams of cooperative agents requires significant coordination and communication efforts. For systems facing a plan failure in a dynamic environment, arguably, attempts to repair the failed plan in general, and especially in the worst-case scenarios, do not straightforwardly bring any benefit in terms of time complexity. However, in multi-agent settings, the communication complexity might be of a much higher importance, possibly a high communication overhead might be even prohibitive in certain domains. We hypothesize that in decentralized systems, where frequent coordination is required to achieve joint objectives, attempts to repair failed multi-agent plans should lead to lower communication overhead than replanning from scratch. Here, we formally introduce the multi-agent plan repair problem. Building upon the formal treatment, we present the core hypothesis underlying our work and subsequently describe three algorithms for multi-agent plan repair reducing the problem to specialized instances of the multi-agent planning problem. Finally, we present an experimental validation, results of which confirm the core hypothesis of the paper. Our rigorous treatment of the problem and experimental results pave the way for both further analytical, as well algorithmic investigations of the problem.