A material selection methodology and expert system for sustainable product design

Material selection is one of the main phases of product design process that has great impact on the manufacturing of sustainable products. One of the best approaches of material selection for sustainable products is life cycle engineering (LCE). But LCE is a costly and cumbersome task and it is not economic to perform this task for a large number of proposed materials in order to choose the most suitable one for a sustainable product. Instead, it is more reasonable to make a preliminary filtering on the proposed materials and obtain a shorter list of candidate materials and then perform LCE on alternatives which are obtained from preliminary filtering. Since environmental friendliness of materials is a critical sustainability issue, so it is a good criterion for preliminary filtering of alternatives. In this paper, a new methodology is proposed to support preliminary filtering of alternatives from environmental viewpoint. The methodology uses the knowledge of experts in the field of eco-design. The knowledge is translated to decision making rules and a decision tree is developed to guide the choice. In order to use the capabilities of frame-based systems, an object-oriented approach for representation of knowledge is also proposed. Moreover, a prototype hybrid expert system based on the proposed methodology called material selection expert system for sustainable product design is developed to support the task of preliminary filtering. Finally, a case study from tire manufacturing industries is presented to show the validity of the proposed system. The results show that the system can determine the appropriate candidate materials and hence improve the possibility of manufacturing of more sustainable products. Eliminating alternatives that do not have the necessary conditions for sustainable product leads to a large saving in time and cost of the LCE evaluation process     

Development of a fuzzy FMEA based product design system

The demand for high-quality and low-cost products with short development time in the dynamic global market has forced researchers and industries to focus on various effective product development strategies. The authors are carrying out research studies to explore the applicability of fuzzy logic and knowledge-based systems technologies to today’s competitive product design and development, with an emphasis on the design of high quality products at the conceptual design stage. A framework of a fuzzy FMEA (failure modes and rffects analysis) based evaluation approach for new product concepts is proposed in this paper. Based on the proposed approach and methodologies, a prototype system named EPDS-1, which can assist inexperienced users to perform FMEA analysis for quality and reliability improvement, alternative design evaluation, materials selection, and cost assessment, thus helping to enhance robustness of new products at the conceptual design stage. This paper presents the underlying concepts of the development and shows the practical application with the prototype system with a case study.     

A morphological approach to product design in a concurrent engineering environment

The development of product design in a concurrent engineering environment requires the consideration and inclusion of life cycle factors early in the design process. This paper proposes a product design framework where these factors are considered. The phases of product design in a concurrent engineering environment include: design requirements, design functions, design alternatives, design attributes, and design environments. A five-step algorithm is proposed by which the optimal design alternative, among all the feasible alternatives, is selected. In order to illustrate the proposed framework, the design of a braking system is presented in each phase. A morphological approach to product design is proposed that consists of two related morphologies. Morphology 1 addresses the innovative aspect of product design. Morphology 2 considers the computational and optimisation aspect of product design. In conclusion, an integrated approach which reconciles both morphologies is suggested.     

A hybrid rough-cut process planning for quality

This paper proposes a hybrid approach to develop a rough-cut process planning for quality. The approach aims to determine key process alternatives with an adequate process capability by systematic quality planning and assessment methods during the initial planning stage of the product development cycle. It consists of four steps: (1) identification of quality characteristics (2) planning of the process quality by combining quality function deployment (QFD) with the process failure mode and effect analysis (FMEA) (3) a selection of process alternatives, and (4) an assessment of process quality through a quality measure index, called the composite process capability (CCP). The process alternatives with an adequate CCP selected during the early design stage can then be not only used as the guidelines for detailed process planning but also as feedback for the product design and other functions for design evaluation and improvement. This approach is helpful to reduce or even eliminate the iterations of modification of process plans. A prototype system called the rough-cut process planning for quality (RPPFQ) has been developed for validation. A case study concerned with a satellite frame part is presented to illustrate the approach and prototype system in this paper.     

A CAD/CAE-integrated injection mold design system for plastic products

Mold design is a knowledge-intensive process. This paper describes a knowledge-based oriented, parametric, modular and feature-based integrated computer-aided design/computer-aided engineering (CAD/CAE) system for mold design. Development of CAx systems for numerical simulation of plastic injection molding and mold design has opened new possibilities of product analysis during the mold design. The proposed system integrates Pro/ENGINEER system with the specially developed module for the calculation of injection molding parameters, mold design, and selection of mold elements. The system interface uses parametric and CAD/CAE feature-based database to streamline the process of design, editing, and reviewing. Also presented are general structure and part of output results from the proposed CAD/CAE-integrated injection mold design system.     

Developing an Integrated Intelligent Framework to Support an Engineering Change Process for an Axial Piston Pump

Since the concepts of concurrent engineering were introduced in mid 1980s, the product design process has become complicated. This is because many factors related to the life cycle of the product may need to be considered during the design stage. Therefore, shortening product development time becomes important for the survival of an enterprise. In this paper, an integrated intelligent environment to support concurrent engineering is proposed. Two major modules are provided by this system to assist change management. One is a constraint network module that analyses the related constraints about a design change to find the design variables influenced. Another is a product assembly module that extracts the design data from a CAD database to analyse the spatial relationships relating to an assembly. The data in the above two modules are integrated in a data integrated module, in which an entity relational data model was developed to describe the integrated data. Finally, a web-based query system was developed to provide a multiplatform environment for the user to refer to the data in the constraint network module and the product assembly module during a design change process. The proposed environment is implemented in the design change process for an axial piston pump.     

A novel method of reverse engineering using axiomatic design

Reverse engineering has been widely used to analyze existing objects such as software systems, products, etc. The main purpose is obtaining information by disassembling a product and finding an improved design. Based on the disassembling work, research for a systematic analysis has been well developed, but reverse engineering has been rarely employed in finding a new (an improved) design of a complex and large scale product. Therefore, even though the ultimate goal of reverse engineering is an improved design (or redesign), the opportunity to make a new feature is rarely given. A novel method of reverse engineering is proposed by using the axiomatic design viewpoint. The method not only keeps the fundamental concept of reverse engineering, but also realizes a new (or improved) design according to proposed procedures such as inference, design improvement module and a qualitative evaluation. A complex and large scale product (a ceiling type air conditioning system) is chosen as a case study to validate the proposed method. As a result, useful information for a new (or improved) design is obtained and also a new part (filter cleaning system) is proposed. The methodology provides a good way to design a new (or improved) product.     

Evaluation of design alternatives in collaborative development and production of modular products

In the globally competitive business environment, collaborative product development has become an important strategy for enterprises to reduce risks and enhance their competitiveness. The planning phase becomes more significant and complicated when utilizing external resources to determine a product solution to achieve customer satisfaction and business goals. The decision process for assessing design alternatives depends on the tradeoffs between quality, time, and cost. In this research, we propose a framework for collaborative product development and production of modular products. It aims at linking customer requirements, generating design alternatives, and then evaluating and selecting these choices to determine the optimum solution. They are considered from both design aspects and manufacturing concerns. Product strategy is discussed as the most important factor in the evaluation process. Further, a practical application of a system-on-a-chip product planning process was carried out to demonstrate the completeness and benefit of our proposed framework.     

An Internet-based integrated product design environment. Part II: its applications to concurrent engineering design

Concurrent or collaborative engineering (CE) has inspired research in the area of design decomposition, which facilitates the concurrency of product lifecycle functions from the earlier stage of the product development process and reduces the complexity of a design problem. The decomposition-based design, on the other hand, necessitates various integration efforts for recombining the decomposed design problems. This is the second of a two-part paper proposing a multi-agent system (MAS) framework for integrated product design in a computer network-oriented CE environment. Part II discusses the applications of the proposed MAS framework to concurrent engineering design. The proposed framework realises the systematic and timely design integrations between multi-functional/cross-functional team members in a dynamic design environment, by enabling model integration, solution integration and tool integration. The proposed design agents make the problem-specific engineering models or heterogeneous design tools interoperable and network-accessible, and also provide the interaction spaces for communicating, integrating or coordinating the individual design solutions. Throughout the paper, the proposed system is illustrated with a successful implementation of a continuously variable transmission (CVT) design problem over the Internet .     

An innovative cost modelling system to support lean product and process development

This paper presents a cost modelling system for lean product and process development to support proactive decision making and mistake elimination at the design stage. The foundations of the system are based upon three lean product and process development enablers, namely: Set-based concurrent engineering, knowledge-based engineering, and mistake proofing (Poka-yoke). The development commenced with an industrial field study of eleven leading European industries from the aerospace, automotive, telecommunication, medical and domestic appliance sectors. Based on the requirements of industrial collaborators, the developed system comprises six modules: value identification, manufacturing process/machines selection, material selection, geometric features specification, geometric features and manufacturability assessment, and manufacturing time and cost estimation. The work involved the development of a feature-based cost estimation method for the resistance spot welding process. The developed system was finally validated using an industrial case study. The developed system has the capability to provide estimates related to product cost and associated values concurrently, facilitate decision making, eliminate mistakes during the design stage, and incorporate ‘customer voice’ during a critical decision making stage.     

An intelligent estimation method for product design time

The planning and control of product development is based on the pre-estimation of product design time (PDT). In order to optimize the product development process (PDP), it is necessary for managers and designers to evaluate design time/effort at the early stage of product development. However, in systemic analytical methods for PDT this is somewhat lacking. This paper explores an intelligent method to evaluate the PDT regarding this problem. At the early development stage, designers lack sufficient product information and have difficulty in determining PDT via subjective evaluation. Thus, a fuzzy measurable house of quality (FM-HOQ) model is proposed to provide measurable engineering information. Quality function deployment (QFD) is combined with a mapping pattern of “function→principle→structure” to extract product characteristics from customer demands. Then, a fuzzy neural network (FNN) model is built to fuse data and realize the estimation of PDT, which makes use of fuzzy comprehensive evaluation to simplify structure. In a word, the whole estimation method consists of four steps: time factors identification, product characteristics extraction by QFD and function mapping pattern, FNN learning, and PDT estimation. Finally, to illustrate the procedure of the estimation method, the case of injection mold design is studied. The results of experiments show that the intelligent estimation method is feasible and effective. This paper is developed to provide designers with PDT information to help them in optimizing PDP.     

Applying TRIZ and AHP to develop innovative design for automated assembly systems

Innovative design in the development of new product and process has become the core value in most business establishments. These innovative designs are often associated with the long-established trade-off compromises or conflicting performance parameters where speed and reliability or quality and cost are readily acknowledged. The rate of change in technology and the commercial environment suggests that the opportunity for innovative design is accelerating and systematic support for innovation process is needed. This study combines the Russian theory of inventive problem solving (TRIZ) and the analytical hierarchy process (AHP) for designing the automated manufacturing systems. This study applied the contradiction matrix table, 40 innovative principles, and 39 engineering parameters to compromise the trade-off between design contradictions and engineering parameters. The design engineers can acquire more feasible solutions and inspiration through the proposed approach. However, due to vagueness and uncertainty in the decision maker’s judgment, an AHP is employed as a decision support tool that can adequately represent qualitative and subjective assessments under the multiple criteria decision making environment. Moreover, the proposed approach can help decision makers facilitate the selection and evaluation of innovative designs in the presence of intangible attributes and uncertainty. In short, the objectives of this research are to use TRIZ to propose the automated design alternatives under the innovative design consideration and to use an AHP to evaluate and select the best feasible alternative under multiple criteria. A case study of designing automated connector assembly line has been used to demonstrate the applicability of the proposed approach.     

A knowledge-based approach for the task implementation in mechanical product design

Although advances have been made to integrate the CAD system with design knowledge, there are still some barriers to apply the knowledge-based design approach to wide practice. A task implementation method is proposed for the mechanical product design process. The design task implementation model is constructed based on its organized-mode and modularity. Declarative knowledge primitives make up of the kernel composition of design task. It makes the design task more controllable and automatable. Solution of the knowledge primitives is directly used to drive the mechanical product. The proposed module has been developed for Intesolid2.0 system, a mechanical CAD system, and it has been evaluated with a design example of a two-stage gearbox.     

Materials selection for environmentally conscious design via a proposed life cycle environmental performance index

Although product design methods are well developed, the recent rise of environmentally conscious design, which includes materials selection as a key element, mandates the development of new engineering tools for decision-making. In this investigation, a method for establishing a life cycle environmental performance index is developed; it is envisioned that the index can be integrated into an environmentally conscious design process. The method addresses such traditional design factors as structural constraints and incorporates an additional consideration, the life cycle environmental impact. The method is applied to the design of an air conditioner support plate. In this application, it is desired to select a material that provides minimal environmental impact, subject to stiffness and strength constraints. Pareto optimization is adopted to analyze the results. The case study shows that the decision-making analysis can provide design guidelines and a criterion for materials selection to achieve environmentally conscious design.     

机电一体化产品概念设计的三层模糊优序评价模型

针对概念设计阶段评价指标及重要度不确定、信息模糊、不完整的特点 ,在模糊理论的基础上提出了一个三层模糊优序评价模型 :模糊预序评价模型 ,模糊半优序评价模型 ,模糊全序评价模型。该模型为概念设计的评价提供了一个较为合理的依据。在文章的最后给出了机电产品的一个应用实例。     

A visualization system for integrating maintainability design and evaluation at product design stage

Thoughtful consideration of products maintenance features early in design stage can reduce or eliminate maintenance costs, reduce downtime, and improve safety. As such, the effective collaboration of product designers and maintenance technicians throughout the product design process is becoming much more important for the most advanced competitiveness. To address this need, a visualization system that enables maintainability-related technicians cooperated with product designers in a networked manufacturing environment is proposed in this study. This paper presents a systematic approach to implementation of a Web-based visualization system by using virtual reality technology. The system aims at providing a simulated environment and concurrent engineering processes to facilitate communication, coordination, control, and integration of product maintainability validation and improvement activities. The result of this research will help increase product maintainability, reduce development cycle time and cost, and hence increase product marketability.     

A Hybrid Intelligent Systems Approach for Die Design in Sheet Metal Forming

Die design is heavily experience based and the die design process is an iterative procedure of trial and error in order to obtain a final die design for the successful manufacture of stampings. Most automotive industries use internal guidelines and past experience for die design. Even though powerful computer-aided design systems are being used in automotive industry, the lack of adequate analysis tools at the initial die geometry design stage hinders the die manufacturing process, and also necessitates lead times of the order of 5–30 weeks [1]. At the concept design stage, and during the initial die development process, the variations in geometry and process conditions are so large that it is prohibitively expensive to use 3D finite element analysis. The complexity of die design heuristic knowledge hinders the development and application of knowledge-based systems. Hybrid intelligent systems are computer programs in which at least one of the constituent models simulates intelligent behaviour [2]. These models could be knowledge-based systems, artificial neural networks, fuzzy logic systems, etc. In this approach both artificial neural networks, knowledge-based systems and finite-element analysis (FEA) for modelling the design process are used. A simulation-based design approach [3] for the die design process is followed. Artificial neural networks (ANNs) are preliminary design tools which indicate the formability of the component geometry, for the selected process and material conditions. The ANN module is trained from FEA results for a generic set of component geometries, process conditions, and material properties. The final die design validation is carried out by FEA. The intelligent frame-work incorporates rules for material selection, process parameter selection and their modification. Component geometry is a critical parameter which affects the manufacturability of the given part. Hence, an intelligent geometry handling module, which automatically modifies and optimises the geometry of the designed die, is implemented in the present system. Knowledge-based blackboard architecture is used for the integration of various analysis models such as CAD, FEA, and ANN, as an intelligent framework for die design [4]. The hybrid intelligent system provides an integrated decision support environment for simulation and analysis of the forming process, both during the initial die design phase and during the die tryout phase. The hybrid intelligent systems approach supports the capability for automatic evaluation of prospective die design for manufacturability, and performs automatic modification of design inputs. Applications of the hybrid intelligent system for die design are described together with a comparison with shop floor data.     

面向主动再制造的产品模块化设计方法

针对面向主动再制造的产品模块化问题,提出了模块化设计流程,结合产品生命周期各阶段特性,从材料的选择与配置、再制造加工性能、使用与维护性、经济性、功能物理可行性等方面制订产品主动再制造模块划分准则。结合模糊动态聚类分析方法,构建产品零部件相似性矩阵,进行产品零部件模块划分,并基于模块内/模块间关联度分析,选取最优阈值,实现模块优化。最后以某款洗碗机产品为例,验证了该方法的有效性。     

Developing a Computer-Aided Environment to Investigate the Influences of Design Schedule Changes on Material Requirement Planning

Recently, the concepts of concurrent engineering have been implemented in many manufacturing areas. However, very few efforts were addressed to linking design procedures and material requirement planning (MRP). In general, an engineering change (EC) might have an influence on the material requirements as well as on the inventory, and hence might affect the manufacturing process. Therefore, it is necessary to consider the material status during the EC stage. This concept has formed a new area for concurrent engineering, that is design for MRP (DFMRP). In this paper, a computer-aided environment that integrates a product data management (PDM) module and an MRP module, to support DFMRP has been proposed. The major function of this environment is to investigate the influence of EC schedule changes on MRP. In other words, this environment provides the information about the influence on MRP when the starting time or finishing time of certain EC tasks have been altered. A process model was developed to describe the relations between EC and production management tasks. In addition, an integration module was developed to extract the related information from PDM and MRP, and to analyse the possible influence on MRP based on the process model. The analysed results can be used as reference information for project management in PDM.     

A Web-based integrated design system: its applications on conceptual design stage

This paper describes the development of a Web-based integrated system for collaborative product development evolving from marketing analysis to prototype generation. The proposed system encompasses a marketing information system (MIS), a human resources management (HRM) system, a supply-chain management (SCM) system, a communication media, an integrated product design studio, a user interface and databases. It enables project planners, marketing analysts, designers, suppliers, and manufacturing planners to work at the early stages to reduce any unnecessary wasted time, resources, and costs, thus increasing the total product quality, maximising the organisation resources used, and reducing the total product cost and product lead time to better face global competition. The tangible advantage of implementing this system is that it provides an integrated environment for total product development from concept to realisation. Therefore, an efficient product development process is generated. One case study is demonstrated and discussed to validate the proposed system.