Scheduling Remanufacturing Activities for the Repair of Turbine Blades: An Approximate Branch and Bound Approach to Minimize a Risk Measure

Refurbished products are gaining importance in many industrial sectors, specifically high-value products whose residual value is relevant and guarantee the economic viability of the remanufacturing at an industrial level, e.g., turbine blades for power generation. In this paper we address the scheduling of re-manufacturing activities for turbine blades. Parts entering the process may have very different wear state or presence of defects. Thus, the repair process is affected by a significant degree of uncertainty. To cope with this, the proposed approach pursues robust schedules minimizing the risk associated to a timely completion time. An approximate branch and bound algorithm is developed grounding on the estimation of the lower bound of the makespan. The viability and efficiency of the approach is assessed through computational experiments grounding on the industrial case under study and a comparison is operated among alternative scheduling approaches.