Constraint-based approach for steelmaking-continuous casting rescheduling

Steelmaking-continuous casting rescheduling problem is an NP-hard problem. In this paper, we present a constraint-based approach for steelmaking-continuous casting rescheduling problem in integrated steel production environment. We treat the steel making-continuous casting rescheduling problem as a dynamic constraint satisfaction problem. To maintain the production stability and the material flow continuity after rescheduling, the perturbation measure function of the model is defined as the summation of the absolute deviation between the new start times and the original start times of operations in continuous casting stage, the variable selection and value selection heuristics is designed based on the resource slackness to minimize the change extent of the rescheduling solution. The resource conflicts in the original schedule are incrementally repaired by the variable selection and value selection heuristics. The validity of the proposed model and approach are demonstrated by the computational examples.