A hybrid CP/MILP method for scheduling with energy costs

This paper deals with energy-related job scheduling for a foundry, in order to minimise the electricity bill. Accounting for energy and human resource constraints leads to better solutions in terms of cost and overall energy consumption. We propose a hybrid heuristic based on a two-step constraint/mathematical programming approach that improves significantly the computation time, compared to the full MILP model. [Recieved: 26 August 2009; Revised: 22 April 2010; Accepted: 13 June 2010]