Production Scheduling with Capacity-Lot Size and Sequence Consideration
The General Lot-sizing and Scheduling Problem (GLSP) is a common problem found in continuous production planning. This problem involves many constraints and decisions including machine capacity, production lot-size, and production sequence. This study proposes a two-phase algorithm for solving large-scale GLSP models. In Phase 1, we generate patterns with a specific batch size and capacity and in Phase 2, based on the patterns selected in Phase 1, we optimize the production allocation. Additionally, the external supplies are included in the formulation to reflect the real situation in business with limited resources. In this work, the justification of the formulation is based on the ability of solving and calculation time. The proposed formulation was tested on eight scenarios. The results show that the proposed formulation is more tractable and is easier to solve than the GLSP.