SIMPLAN is a multi-period mixed integer linear programming model for the simultaneous planning and scheduling of a sigle-stage multi-product continuous plants with parallel units.
This proposed model becomes computationally expensive to solve for long time horizons. In order to address this problem, we apply a bi-level decomposition algorithm in which the original problem is decomposed into an upper level planing and a lower level scheduling problem. To represent the upper level we use an MILP model based on a relaxation of the original model. In the lower level the simultaneous planning and scheduling model is solved for a subset of products predicted by the upper level.
SIMPLAN is based on the paper 'Simultaneous planning and scheduling of single-stage multi-product continuous plants with parallel lines' by M. Erdirik-Dogan and I. Grossmann (2006); and has been developed by Rosanna Franco and Ricardo Lima under the supervision of Ignacio E. Grossmann.