Perspectives on model based integration of process operations

Decomposition techniques for the solution of large‐scale scheduling problems

“…From the UDM formulation, a more compact but less exact formulation can be easily constructed (Bassett et al, 1996). This formulation is referred to as an uggregute formulation because it is generated by summing over all the UDM variables and constraints for a predetermined set of discrete time intervals (in other words, aggregating the UDM formulation).…”

“…Under such approaches the planning and scheduling problems are solved iteratively, but the various approaches utilize different techniques to remove infeasibilities. The first approach is a heuristic technique presented in Bassett et al (1996) which utilized an ad-hoc modification of infeasible schedules to obtain feasible solutions. Subsequent approaches use constraint modification and constraint disaggregation to remove infeasible solutions from consideration, thus removing the ad-hoc nature of the first approach.…”

Planejamento e programação da produção em plantas multipropósito operando em batelada na indústria química

“…Na literatura acadêmica da área de engenharia química a linha principal tem sido o desenvolvimento de modelos de planejamento simplificados baseados nos modelos da programação de produção, pela agregação do tempo e da agregação de restrições (KUDVA et al, 1994;BASSETT et al, 1996e SUBRAHMANYAM et al, 1996. O objetivo são modelos simplificados que são utilizados, a partir de formulações de programação mista, para determinar os requisitos de produção em cada período de tempo agregado.…”

A Decomposition Method for the Simultaneous Planning and Scheduling of Single-Stage Continuous Multiproduct Plants

“…Note that according to equations (2) and (3a), exactly one processing time is non zero in the summation term of (6). Constraint (7) defines the transition variables for the transitions that occur across successive weeks.…”