In this paper an approach for flexible production scheduling for continuous multi-grade chemical processes is proposed. The approach integrates the economics of production and of company-market interaction for single-machine multi-grade continuous processes. The operation of a continuous multi-grade plant is modeled utilizing the detailed inclusion of grade transitions and sales orders and opportunities. The added value of the operation, which is used as the criterion function, is modeled by analyzing the costs and benefits of plant operation. The model results in a mixed integer linear program which is solved to compute suitable short term production and sales decisions. The approach is demonstrated on a gas phase HDPE manufacturing plant. (c) 2005 Elsevier Ltd. All rights reserved.