Slot Models for Schedulers Enhanced by Planning Capabilities

Scheduling is one of the most successful application areas of constraint programming and, recently, many scheduling problems were modelled and solved by means of constraints. Most of these models confine to a conventional formulation of a constraint satisfaction problem that requires all the variables and the constraints to be specified in advance. However, many application areas like complex process environments require a dynamic model where new activities are introduced during scheduling. In the paper we propose a framework for constraint modelling of dynamic scheduling problems with activities generated during scheduling. We also show how some typical scheduling sub-problems like alternatives, set-ups and processing of byproducts can be modelled in this framework.