Large-scale Hydropower Equipment Manufacturing Enterprise Oriented Hierarchical Production Planning Management System And Its Application

Large-scale hydropower equipment manufacturing enterprises have variable production requirements, variety of production type, large firm size and complex product structure. Therefore, research and exploration of its production planning management has important application significance and reference value for improving the production management level of the whole complex equipment manufacturing industry. Based on analyzing the problems exists in the production planning management of the similar manufacturing enterprise at home and abroad, a new Key Equipment Constrained Hierarchical Production Planning Management methodology (KEC-HPPM) for large-scale hydropower equipment manufacturing enterprises is proposed, according to its production features. And then several key technologies are also studied.Firstly, the hierarchical production planning management model, which consists of company planning layer, plant planning layer and job shop scheduling layer, is proposed by introducing TOC into hierarchical production planning mode and integrating network planning, MRP and dynamic scheduling theory. The principle and workflow are described, a corresponding network/BOM data model is also built, so that the theoretical foundation of the following application development and key technology research can be laid.The core issue of company planning layer is key equipment constrained multiple projects scheduling problem, and it is hard to solve when the scale of problem becomes large. Therefore, a fast fitness evaluation method based genetic algorithm is put forward. In this algorithm, the fitness value is estimated based on interpolation theory, according to the similarity between the parents and the offspring, therefore the calculation amount can be reduced effectively. Simulation experiments show that the proposed algorithm has a faster solving speed than normal GA, and is suitable for large-scale projects scheduling problem.Inserting a reasonable buffer time prior to the key operation can effectively reduce the production fluctuations, and insure the key equipment schedule is implemented accurately. Considering that the existing buffer sizing methods are all empirical, an Availability Theory based buffer sizing method is proposed. Firstly, the buffer time sizing formulas with four different feeding operation forms are built. Then, an improved fuzzy probability PERT method is proposed to verify the reliability of buffer time. At last, the buffer time optimization model is built, to minimize the sum of key equipment idleness penalty and extra WIP cost. Simulation experiments show that the buffer time size estimated by the proposed method is reasonable and reliable.The workflow of plant planning layer, which consists of key equipment schedule implement, material requirement planning and plant production planning, is proposed based on analyzing its tasks and goals. Then the corresponding material requirement planning and production planning algorithms are put forward. Besides, the optimal co-production factory selection method for the outsourcing factory selection problem with uncertain decision-making attributes is proposed, by introducing interval number and multi-attribute decision theory.In order to cope with the complex and changing environment in job shop, a dynamic job shop scheduling model based on multi-agent technology and Q-learning algorithm is proposed. In this model, the schedule is generated by negotiation between equipment agents, based on improved Contract Net mechanism and Q-learning based tender selection strategy. In order to improve the learning effects of Q-learning in dynamic scheduling environment, a clustering based state space dividing method and state membership based state-action pair value updating strategy are proposed.Finally, the application of KEC-HPPM at large-scale hydropower equipment manufacturing enterprises is discussed, by implementing KEC-HPPM and developing a key equipment constrained hierarchical production planning management system for Harbin Electric Machinery Co. Ltd. Based on analyzing the production planning management requirements of Harbin Electric Machinery Co. Ltd, the function module, the system architecture and the detailed design process are introduced. The running examples and implementation results analysis are also presented, demonstrating that the proposed technology, theory and methods are valid and effective.