Towards Explainable AI Planning as a Service
  Explainable AI is an important area of research within which Explainable
Planning is an emerging topic. In this paper, we argue that Explainable
Planning can be designed as a service -- that is, as a wrapper around an
existing planning system that utilises the existing planner to assist in
answering contrastive questions. We introduce a prototype framework to
facilitate this, along with some examples of how a planner can be used to
address certain types of contrastive questions. We discuss the main advantages
and limitations of such an approach and we identify open questions for
Explainable Planning as a service that identify several possible research
directions.
