Research On Product Design Change Impact Analysis And Intelligent Optimization Method With Cascading Failure Mechanism

Design changes are inevitable in the product design and development process.When the amount of change exceeds the tolerance margin of a component/part of a product,the corresponding component needs to be modified to meet the change requirement.Due to the complex correlation between components,changes to one component often lead to changes to other related components,and also have a negative impact on the entire product design network including suppliers.Design changes and their propagation affect the product development cycle,cost,and quality.How to reveal the propagation process of product design changes and control the impact of change propagation is a hot and difficult research topic in the field of product design.Aiming at the issue of product design changes,this thesis deeply studies the product design change propagation model and its intelligent optimization method based on cascading failure mechanism.The main research contents are as follows:(1)To accurately describe the dynamic propagation process of product changes,a cascading failure propagation model is established for a dual-layer network of components and suppliers.Firstly,the influence of suppliers and manufacturers on design change propagation is considered simultaneously.A dual-layer product design network that integrates components and suppliers is constructed with components and their suppliers as nodes.Then,the change source is regarded as the initial failure node,and the cascading failure mechanism of the network is used to analyze the propagation process of the change,establishing a cross-layer cascading failure model for the duallayer product design network.Next,considering the change in the average load of neighboring nodes,a bilateral change impact evaluation index with the load margin is defined to identify important nodes in the network and predict the product’s resistance to change.Finally,taking a design change problem for a specific model of TV at Skyworth Company as case,the effectiveness of the proposed model and the prediction method is verified.(2)To effectively control the impact of design change propagation on the product quality and robustness,a particle swarm optimization-based optimization method for product design tolerance is proposed.Firstly,with the help of the established cascading failure propagation model,the range of impact of design changes on the entire product network and the degree of impact on key component nodes are calculated,and a new robustness evaluation index for product component network is defined;Secondly,taking product robustness and product quality loss as two optimization objectives,and processing capacity as constraints,a multi-objective optimization model for the tolerance allocation problem is established;Subsequently,an improved particle swarm optimization algorithm with inertia weight is introduced,and an intelligent optimization method for the model is given.Finally,taking the DC-DC circuit system of a TV as case,the applicability or effectiveness of the proposed model and method is verified through example analysis.This thesis has 25 figures,7 tables and 94 references.