A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Abstract

Mathematical models for scheduling of multipurpose batch processes have been developed in the last three decades. However, none of these models, consider production and consumption tasks related to the same state at the same time event point. Furthermore, a great number of task-specific models are considered as unit-specific instead in the literature. In this work, we are going to distinguish these two different approaches. Two novel mathematical models based on task-specific and unit-specific approach respectively for scheduling of multipurpose batch processes with unlimited intermediate storage are proposed. Both mathematical models allow production and consumption tasks to take place at the same time event point. We also introduce a new definition of recycling and non-recycling tasks, so as to define, whether it is possible production and consumption tasks related to the same state to take place at the same time event point or not. Unit-specific event based formulation is the most superior for this type of model, since it generates the optimum solution in up to one magnitude less computational time.