Add to ORKGBatching jobs in a manufacturing system is a very common policy in most industries. Main reasons for batching are avoidance of setups and/or facilitation of material handling. Batch processing systems often consist of multiple machines of different types for the range and volumes of products that have to be handled. Building on earlier research in aircraft industry, where the process of hardening synthetic aircraft parts was studied, we discuss a new heuristic for the dynamic scheduling of these types of systems. It is shown by an extensive series of simulation experiments that the new heuristic outperforms existing heuristics for most system configurations.</p