Relationships between the complete set of parts and product BOM are researched in assembly process for complex products.With regard to the discrete manufacturing industry,delivery BOM model is put forward based on technical process and manufacturing BOM in Enterprise Resources Planning(ERP) application system. According to the BOM model,the task of material delivery is implemented,the complete set ratio of parts for assembly producting schedules can be achieved. In addition, dynamic attribute information of parts and products can be recorded accurately.