Finding Inter-Related Plans

In many planning situations, a planner is required to return a set of plans satisfying the same goals which will be used by the external systems collectively. The external systems can specify the desired inter-relationships among the returned plans (e.g., diverse plans, similar plans, non-dominated plans) and the task of the planner is to return a set of plans which will meet these requirements. As an example, in adaptive web services composition, the web service engine wants to have a set of diverse plans/ compositions such that if there is a failure while executing one composition, an alternative may be used which is less likely to be failing simultaneously. In this paper, we investigate the problem, propose functions for defining similarity among plans and propose methods to find sets of inter-related plans.