Research On Closed-loop Management For Lifecycle Data Based On Product Morphology

Manufacturing industry is the fundamental, advanced and strategic cornerstone industry, and its competitiveness focuses on innovation and service of product. Influenced by acquisition and handling mechanism of product data, full lifecycle information store, seamless integration of data, rapid acquisition of new data and effective reuse of old data are hardly achieved. And the development of product innovation and service is blocked. Therefore, this paper studied the data acquisition, lifecycle unified data model and closed-loop data management based on data exchange, meta-data, meta-model, data modeling, data tracking and reverse tracing. The proposed closed-loop management of product data facilitates the effective management, supply and utilisation of product data, improves the product quality and sharpens the competitiveness edge of enterprises.Study of data acquisition-XML was used to build data exchange model, in order to eliminate the heterogeneity of data to be exchanged. The formats of structured data and unstructured data were managed by meta-data, trees, queues and hash tables. Structured data were divided into static data and dynamic data. Dynamic data comprised time-based, event-based and message-based data. Thus product data could be exchanged among several PLM-centered agents. To support data acquisition and exchange modes, a data acquisition framework comprising4layers of data storage, management, transmission, and acquisition was built. The framework was a feasible scheme for data acquisition in that it enabled positive/negative upload, and integrated/automatic access of product data. Study of unified data model-The product morphology including model product, design product and physical product were proposed. Data characteristic and evolution laws of product morphology are the key factors for unified data management. Object Oriented (00), UML and meta-data were used to build unified data model of product lifecycle, including model-product data model, design-product data model and physical-product data model. Model-product data model was a single data model. Design-product data model was made up of core data model and phase ruler filters. Physical-product data model comprised core data model and phase private data models. All the data were unitively managed, and effectively stored using mapping of fundamental objects to manage relations of evolution. In order that data model fits development of business, a customized approach of data model was exhibited. Its framework and customized method were established. The approach extended the application range of data model, reduced the workload of customized and further development, and achieved rapid implementation of PLM system.Study of data closed-loop management-Product-morphology evolvement tree, which described the evolvement among three product forms, managed structre and object information of one product form, and mapping, homology and borrow information of components among product forms. Data closed-loop management model supporting data integration and share among three product forms was put forward. Respective mapping of attribute and structure was discovered, and the mapping rules were built too. Mathematical models of data tracking and data reverse tracing were formulated, including object tracking, structure tracking, object reverse tracing, structure reverse tracing and mapping matrix tracking. Homology matrix and borrow matrix were used to achieve homology and borrow management of design components, and homology management of physical components. Then the capacity of PLM automatically supplying data for business was improved.Based on the studies above, an interactive scheme of product design and service was proposed. With data closed-loop management model, failure cases from homologous physical product could feed back to design phase and then Severity degree, Occurrence degree, Detectability degree and Risk Priority Number (RPN) of every failure mode were got. Design Failure Mode and Effects Analysis (DFMEA) were conducted, and design improvement and data fusion of failure cases and failure mode were achieved. The objectivity and precision of DFMEA were improved. Then the approach of data reverse tracing from service object to its design provenance was discussed.Finally, a PLM system-InforCenter achieving data closed-loop management was developed and implemented on shipbuilding plant. InforCenter managed the data of model ship, design ship and physical ship, and their data could feed forward and back. Then the data of design and service could support each other, and the data-management capacity of shipyard was improved.