The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and r...The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and reduce production cost. Therefore, a cooperative strategy is needed to concurrently solve the above issue. In this paper, the cooperative optimization model for RMT configurations and production process plan is presented. Its objectives take into account both impacts of process and configuration. Moreover, a novel genetic algorithm is also developed to provide optimal or near-optimal solutions： firstly, its chromosome is redesigned which is composed of three parts, operations, process plan and configurations of RMTs, respectively; secondly, its new selection, crossover and mutation operators are also developed to deal with the process constraints from operation processes （OP） graph, otherwise these operators could generate illegal solutions violating the limits; eventually the optimal configurations for RMT under optimal process plan design can be obtained. At last, a manufacturing line case is applied which is composed of three RMTs. It is shown from the case that the optimal process plan and configurations of RMT are concurrently obtained, and the production cost decreases 6.28% and nonmonetary performance increases 22%. The proposed method can figure out both RMT configurations and production process, improve production capacity, functions and equipment utilization for RMT.展开更多
Many smaller manufacturers utilize production systems such as ＂individual production＂ and the ＂production of many models in small quantities.＂ In the processes for the ＂production of many models in small quantit...Many smaller manufacturers utilize production systems such as ＂individual production＂ and the ＂production of many models in small quantities.＂ In the processes for the ＂production of many models in small quantities＂ by multi-skilled workers, a manufacturer cannot make good use of the management method with standardized work tables used by large enterprises. Thus, it is necessary to develop ways to f＇md standardized work that is suitable for smaller enterprises. Therefore, we investigated two kinds of factories that utilized flexible manufacturing procedures for the ＂production of many models in small quantities,＂ and considered their work instructions, work contents, changeover methods, workers＇ abilities, etc. One of the compared processes was a case where there was defined standardized work, which was not observed. In the other, a QA （quality assurance） network was created to guarantee the quality. Based on the investigation results, we formulated improvement plans, had the supervisors review them, and clarified the characteristics of their problems. The results revealed areas where much attention was required to find standardized work for such processes. In addition, we made it possible to support the specification of difficult tasks and the renewal of standardized work by extending a standardized work table for the entry of workers＇ actions. This paper reports a method to define and make good use of standardized work tables and standardized work combination tables, i.e., a way to find and use standardized work based on the results of the previously mentioned factory investigation.展开更多
Design and manufacture organizations currently suffer from a number of problems that aignificantly affect their productivity.Despite their fragmented efforts to automate portioas of operations,they still suffer from &...Design and manufacture organizations currently suffer from a number of problems that aignificantly affect their productivity.Despite their fragmented efforts to automate portioas of operations,they still suffer from 'islands' of designing and manufacturing automation,long lead time for semi-custom proposals and engineering work, lengthy cycles of product development and introduction into the market,and low morale due to boring,repetitive engineering and industrial design activities.Thereby,the integration of design and manufacturing poses to the CAD/CAM researchere a series of challenges.The paper introduces a methodology that allows for the integration of product design with manufacturing process planning and the application of a new software technology known as 'Object-Oriented Intelligent Programming' .The task is achieved through an object-oriented intelligent CAD/CAM environment where a design model from the CAD system can be analysed, and manufacturing process plans with specifications of machining can be automatically determined.The manufacturing information of a part is extracted from the 3D geometric model and the 2D engineering drawing,thus,both geometric and non-geometric attributes of a part can be obtained.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 51005169, 50875187, 50975209)Shanghai Municipal Natural Science Foundation of China (Grant No. 10ZR1432300)+1 种基金International Science & Technology Cooperation Program of China (Grant No. 2012DFG72210)Zhejiang Provincial Key International Science & Technology Cooperation Program of China (Grant No. 2011C14025)
文摘The production process plan design and configurations of reconfigurable machine tool （RMT） interact with each other. Reasonable process plans with suitable configurations of RMT help to improve product quality and reduce production cost. Therefore, a cooperative strategy is needed to concurrently solve the above issue. In this paper, the cooperative optimization model for RMT configurations and production process plan is presented. Its objectives take into account both impacts of process and configuration. Moreover, a novel genetic algorithm is also developed to provide optimal or near-optimal solutions： firstly, its chromosome is redesigned which is composed of three parts, operations, process plan and configurations of RMTs, respectively; secondly, its new selection, crossover and mutation operators are also developed to deal with the process constraints from operation processes （OP） graph, otherwise these operators could generate illegal solutions violating the limits; eventually the optimal configurations for RMT under optimal process plan design can be obtained. At last, a manufacturing line case is applied which is composed of three RMTs. It is shown from the case that the optimal process plan and configurations of RMT are concurrently obtained, and the production cost decreases 6.28% and nonmonetary performance increases 22%. The proposed method can figure out both RMT configurations and production process, improve production capacity, functions and equipment utilization for RMT.
文摘Many smaller manufacturers utilize production systems such as ＂individual production＂ and the ＂production of many models in small quantities.＂ In the processes for the ＂production of many models in small quantities＂ by multi-skilled workers, a manufacturer cannot make good use of the management method with standardized work tables used by large enterprises. Thus, it is necessary to develop ways to f＇md standardized work that is suitable for smaller enterprises. Therefore, we investigated two kinds of factories that utilized flexible manufacturing procedures for the ＂production of many models in small quantities,＂ and considered their work instructions, work contents, changeover methods, workers＇ abilities, etc. One of the compared processes was a case where there was defined standardized work, which was not observed. In the other, a QA （quality assurance） network was created to guarantee the quality. Based on the investigation results, we formulated improvement plans, had the supervisors review them, and clarified the characteristics of their problems. The results revealed areas where much attention was required to find standardized work for such processes. In addition, we made it possible to support the specification of difficult tasks and the renewal of standardized work by extending a standardized work table for the entry of workers＇ actions. This paper reports a method to define and make good use of standardized work tables and standardized work combination tables, i.e., a way to find and use standardized work based on the results of the previously mentioned factory investigation.
文摘Design and manufacture organizations currently suffer from a number of problems that aignificantly affect their productivity.Despite their fragmented efforts to automate portioas of operations,they still suffer from 'islands' of designing and manufacturing automation,long lead time for semi-custom proposals and engineering work, lengthy cycles of product development and introduction into the market,and low morale due to boring,repetitive engineering and industrial design activities.Thereby,the integration of design and manufacturing poses to the CAD/CAM researchere a series of challenges.The paper introduces a methodology that allows for the integration of product design with manufacturing process planning and the application of a new software technology known as 'Object-Oriented Intelligent Programming' .The task is achieved through an object-oriented intelligent CAD/CAM environment where a design model from the CAD system can be analysed, and manufacturing process plans with specifications of machining can be automatically determined.The manufacturing information of a part is extracted from the 3D geometric model and the 2D engineering drawing,thus,both geometric and non-geometric attributes of a part can be obtained.
