Development of mathematical programs for evaluating dynamic and temporal flexibility indices based on KKT conditions

In addition to the economic criteria, it is equally important to consider operational flexibility in a realistic process design. Two quantitative measures, i.e., the dynamic and temporal flexibility indices, have already been proposed in the past to characterize the batch or unsteady operations, and the corresponding multi-level dynamic programming models have also been developed for calculating such metrics. However, the available algorithms are still not mature enough to ensure computation accuracy and/or to guarantee convergence in every optimization run. These drawbacks have been circumvented in the present study by converting the above models into single-level ones on the basis of the Karush-Kuhn-Tucker (KKT) conditions. The numerical results obtained in several case studies are reported in this paper to demonstrate the benefits of the proposed solution strategy.