Unit-specific event-based continuous-time approach for short-term scheduling of batch plants using RTN framework

The problem of short-term scheduling of batch plants has received remarkable attention in the past two decades. The state-task-network (STN) and resource-task-network (RTN) process representations are extensively used in modeling scheduling problems. In this paper, we propose a new model to investigate the RTN representation for unit-specific event-based models. For handling dedicated finite storage, a novel formulation is proposed without the need for considering storage as a separate task. The performance of the proposed model is evaluated along with several other continuous-time models from the literature based on the STN and RTN process representations. The various models are assessed based on our implementations using several benchmark example problems from the literature. Two different objective functions, maximization of profit and minimization of makespan, are considered. Two storage policies, unlimited and dedicated finite storage cases are also considered. (C) 2007 Elsevier Ltd. All rights reserved.