Study On The Production Planning Modus And Model In Auto Manufacturers

With the continuous deepening of reform and sustained economic growth, the demands of auto are growing substantially; the auto company must improve customer service levels and shortened the order-to-delivery time to improve their competitiveness. At the same time, year on year growth rates fluctuated while the auto production capacity constantly rising, so if we forecast the future production volume, preparation and organization of production only based on historical sales data, the market volatility will impact the following parts demands planning and production scheduling. So the auto companies need to solve the problem how to make the production of parts demand planning and production arrangements flexible.Most of auto companys implement enterprise resource planning system (ERP) currently, but the management model of ERP is still manufacturing resource planning (MRPII), the method of planning are material requirement planning (MRP) and master production schedule (MPS), though the ERP system consider the capacity of production planning resource constraints, it is still a serial process of verification processing.Advanced Planning and Scheduling (APS) is a constraint-based scheduling and limited ability planning, it is an optimization techniques based on the resource constraints, not only for the short-term planning and scheduling within the individual enterprise, but also for long-term forecasts on the basis of the known conditions in enterprises. APS systems and ERP systems can be integrated by separation or common approach method.The business plan of the auto company can be divided into strategic planning, tactical planning and operational planning in APS-based planning framework. Strategic planning decides the development direction of the company, tactical planning decides how to achieve the business strategy, and operation planning reflects the real plan of the tactical level. Through the implementation of the planning to achieve the strategic and tactical planning in program level.The bill of material (BOM) is a static structure in MRP system, there is no details production processing information in it, so we need to create a configurable BOM in APS system which will be involved the different production process, processing time, needed materials, resource and the logical relationship between the different processes, all the informations will be mixed and changed dynamically in time, we can establish a dynamic production process and production structure based on the configurable BOM.Consider the applicability, flexibility and convenience of the planning system, the paper proposed an integrated model of APS and ERP based on common object request broker architecture (CORBA), the advanced planning and scheduling mixed-model is combined with the planning model in ERP system to achieve the complete processing from optimized scheduling to the executing process. The model is a separating data type model. APS and ERP have independent databases and user interfaces. Import the planning and basic data through CORBA supporting platform int APS system for rapid optimization and ordering calculation, the planner adjusts and confirms the final decision from the multiple optimized programs, and the determined optimal programs will be exported into ERP system for future operational processing through the CORBA platform.The third-party logistics provides the transportation services inmost auto company, due to restrictions on third-party logistics services level, the third-party logistics can't delivery the parts to the plant in time, there have impact on the OEM's production line and confused the daily output and scheduling. The paper presents an optimal lot-size control strategy which ground on the dynamic safety stock on the basis of logistic service level. By calculating the dynamic safety stock in every order cycle in the model and attaching the result to the original plan to avoid the risk in the production line caused by the fluctuations of service level.The influence to logistics transportation caused by the weather conditions is increasing. Rainy and foggy have a great impact on road transportation in summer in the south, and snow and ice caused the cycle of transportation longer in winter in the north, so if the weather is changed, the supplier which the lead time is fixed will delay the goods delivery. Based on the case of short-distance road transportation, the paper put forward a way which dynamic change the safety stock according to the short-term weather forecasting and order the safety stock in advance to ensure the inventory levels. The method can meet the demands if the goods delivery delayed due to the weather factors.As CKD suppliers are generally in foreign countries, and the vendor's information system are different, so there is no a valid inventory management planning system for CKD parts ordering. The CKD parts ordering methods are usually the bulk orders, that means only the quantity reach certain level can be ordered. this will lead to inflated order quantity and increasing stock since the ordering quantity are not match the real requirements. The article propose a single part ordering procedure control system architecture and model on the basis of inventory management system, in-transit inventory control system and the MRP planning system. And the ordering planning generated by this model can be directly via EDI to CKD suppliers, it requires the original packaging and send to production lines directly, and it will reduces the packaging costs and other logistics costs since there is no intermediate links. The actual inventory levels of parts will descreased because MRP system takes into account both the actual physical inventory and in transit inventory.