Operations scheduling in make-and-pack production: Schedule construction and GA-based priority-rule generation procedures

Make-and-pack production processes are vital to, e.g., the consumer industry or the pharmaceutical industry. Production facilities used for such processes can be divided into a make stage, a pack stage, and a set of storage tanks which decouple the two stages. In operations scheduling, complex technological constraints must then be considered, e.g., non-identical parallel processing units, sequence-dependent changeovers, batch splitting, material transfer times, minimum storage times, and finite storage capacity. In this paper, we present an effective and generic heuristic for operations scheduling in such production processes. The heuristic consists of a genetic algorithm for generating priority rules which are used to sort the operations to be scheduled, and a scheme for scheduling the operations in the devised order. Our computational results for a make-and-pack production process from the consumer industry indicate that this heuristic outperforms the state-of-the-art solution methods.