Sequencing intermediate products: A practical solution for multipurpose production scheduling

• Published in: Computers & chemical engineering Vol. 20; pp. S1137 - S1142
• Main Authors: Graells, M., Espuña, A., Puigjaner, L.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 1996; Elsevier
• Subjects: Applications of mathematics to chemical engineering. Modeling. Simulation. Optimization; Applied sciences; Chemical engineering; Exact sciences and technology; Chemical plant; Batchwise; Multipurpose installation; Simulated annealing; Scheduling; Optimization; Stochastic programming
• ISSN: 0098-1354; 1873-4375
• DOI: 10.1016/0098-1354(96)00197-4

In the present work, the production scheduling problem in multipurpose batch chemical plants operating under mixed intermediate storage policies is submitted to a new practical review leading to simplified and realistic solutions. Customer satisfaction is set as the main problem objective instead of minimization of well-known performance criteria such as makespan or flowtime and deviation of resulting production profile from desired deliveries is minimised using penalty functions including costs for stock and delay. The need to synchronise requirements and availability of the precise amounts of intermediates and products to a timetable is achieved by identifying multipurpose schedules as sequences of integers related to production runs of stable intermediates. Such a dramatic simplification of the problem allows the satisfactory use of stochastic optimization techniques (SA) for the matching of deliveries and due dates.