Flowshop scheduling model for bespoke precast concrete production planning

Bespoke precast concrete products are particularly designed and custom made for a construction project. The production planning of these products is complicated that considers important concerns, i.e. the reliability of the product delivery programme, the short lead-time competitiveness, and the effective utilization of purpose-built precast moulds. The planning has a high impact on the success of the production. The characteristics of the bespoke precast production are formulated with the flowshop scheduling technique so that an effective production plan can be arranged to meet these concerns. Genetic algorithm is used in the scheduling optimization. Its multi-objective function includes total flowtime, total machine idle time, and total tardiness and earliness. After the model formulation, sensitivity analyses are conducted on the three model's parameters namely the number of mould availability, the processing time changes, and the weighting of the multi-objective function. The proposed model is anticipated to support the planners to arrange economic and efficient production plans. Also, it can be used to determine the suitable number of moulds, the accuracy of the processing time estimation, and the weighting strategy of the multi-objective optimization.