Planning – Scheduling Connections through Exogenous Events

Abstract

Exogenous events appear in many practical planning and scheduling problems but until recently only the latter methodology has commonly dealt with them. On the one hand, exogenous events that are represented as instantaneous actions occur at specific time points and interact with actions. On the other hand, exogenous events can often be seen as enforcing earliest starting time and latest finishing time constraints on actions. Such constraints are common in scheduling, suggesting that exploiting related techniques from the scheduling community might be effective in a planning context. In this paper, we look at heuristic techniques from both the planning and scheduling fields that are relevant to this problem, and consider combined approaches that may be more effective when planning in the presence of the type of constraints imposed by exogenous events.