Analysing creative behaviour in the later stage design process

Creativity is widely seen as an important subject in the study of the engineering design process. This paper presents a framework and coding scheme for the analysis of creative designer behaviour within the later stage engineering design process, validated through a longitudinal study. By classifying the tasks that designers complete throughout the design process, analysis has demonstrated two different approaches to creative behaviour in later stage design; dependent on the way in which designers identify, develop and use knowledge and design variables. Through such analysis, the understanding required to develop specific and particularly appropriate methods of designer support can be gained, dependent on the stage of the design process and particular approach of the designer.     

Optimizing the decision-making process for large-scale design problems according to criteria interrelationships

As the scope of elements considered by product designers has widened, the number of design criteria and variables has mushroomed. Broad concerns, such as product life cycle as well as specific and detailed user requests, must all be addressed and their respective priorities balanced. Companies now face a twofold difficulty with design projects: the need to deal with them as large-scale optimization problems and the need to shorten the development cycle to a certain period. With respect to the design stage, this paper proposes a concurrent criteria-sequencing method for large-scale design optimization problems that not only yields an optimum criteria order for evaluation, but also shows which criteria can be evaluated in parallel. This method consists of two main techniques based on criteria interrelationships: the selection of criteria blocks (i.e. collaborative blocks and parallel blocks) and the sequencing of both the criteria blocks and the criteria within them, with the aim of minimizing the design time. Using a hierarchical decomposition approach, the relationships between each criterion and the design variables of which it is composed are clarified, resulting in the selection of closely interrelated criteria, which are then arranged in blocks. To demonstrate the method's effectiveness, it is applied to the design of an urban bicycle.     

Structural relationship model for design defect and influencing factors in the concurrent design process

Concurrent design is a systematic approach that aims to help developers consider all elements related to the product life cycle, including quality, cost, schedule and user requirement. This approach is challenging because designers conduct these elements manually in the design process. In addition, studies on the formation mechanism of design defects are limited. To minimise the difficulties of product designers and prevent design defects, a structural relationship model is presented for the concurrent design process. The structural relationship model, which incorporates design defects, design process and influencing factors, is marked through polychromatic sets. The interval analytic hierarchy process is used to determine the weight of each influencing factor. Furthermore, a brief model instruction for concurrent design is proposed to guarantee the model application’s validity. The proposed method enables designers to concentrate on functionality and performance design, and the findings are expected to be theoretically and practically useful for preventing and controlling defects in concurrent design.     

An innovation funnel process for set-based conceptual design via DOE exploration,DEA selection and computer simulation

This paper presents a conceptual design approach including pattern creation from designers, alternative exploration with a DOE matrix, alternative analysis via computer simulation and alternative selection by DEA analysis. Designers possessing domain knowledge create various design patterns to meet the requirements of product performance and customer expectations. Then, based on these design patterns, the alternatives, considered as decision-making units (DMUs), are extracted from various quality level combinations by following the use of the DOE matrix. The nature of the DOE matrix ensures that distinctive representatives are constructed for all design alternatives. The total alternatives (DMUs) consist of the alternatives associated with all the patterns. Computer simulation with ANSYS software is introduced to convert the quality level combination of each alternative (DMU) into simulated outputs, which are further categorised into DEA inputs and DEA outputs for DEA frontier analysis. Four DEA methods, CCR-min input, CCR-max output, BCC-min input and BCC-max output, are used for analysing typical market representatives resulting from market uncertainty. The found efficiencies are used to rank and select the explored alternatives (DMUs) for the next stage of the detailed design. A bike-frame product is chosen as an example to demonstrate the proposed approach. The results clearly show that the proposed approach enables designers to economically select appropriate design alternatives that satisfy performance expectations during the conceptual design stage.     

A novel systematic method to evaluate computer-supported collaborative design technologies

Selection of suitable computer-supported collaborative design (CSCD) technologies is crucial to facilitate successful projects. This paper presents the first systematic method for engineering design teams to evaluate and select the most suitable CSCD technologies comparing technology functionality and project requirements established in peer-reviewed literature. The paper first presents 220 factors that influence successful CSCD. These factors were then systematically mapped and categorised to create CSCD requirement statements. The novel evaluation and selection method incorporates these requirement statements within a matrix and develops a discourse analysis text processing algorithm with data from collaborative projects to automate the population of how technologies impact the success of CSCD in engineering design teams. This method was validated using data collected across 3 years of a student global design project. The impact of this method is the potential to change the way engineering design teams consider the technology they use and how the selection of appropriate tools impacts the success of their CSCD projects. The development of the CSCD evaluation matrix is the first of its kind enabling a systematic and justifiable comparison and technology selection, with the aim of best supporting the engineering designers collaborative design activity.     

Cognitive basis for conceptual design

Engineering design is a highly iterative process. Nevertheless, the set of solution principles obtained during the conceptual phase seems to establish the universe of discourse for that design task. The richness, fertility, and completeness of this set of solution principles critically affects the character of the design to be. This seed pool of ideas seems to shower only the gifted designers and problem solvers. The moment of creation, the breakthrough, always has an aura of mystery surrounding it. However, it is important that this process be studied empirically. This article presents an operational model of the cognitive processes at the breakthrough stage of conceptual design. The model is then used to analyze some illustrative examples. We believe that this initial operational glimpse into how ideas happen will help designers confront unsolved problems. This operational view of the creative process may also influence how designers will be trained in problem solving.     

Incorporation of high recyclability material selection in computer aided design

Manufacturing are now under increasing pressure of tighten environmental legislation to preserve natural resources. Product design, as a part of manufacturing activities, has to be more concern to deliver product specification with reduced environmental impact. Design for Recycling (DFR) is one of the promising approaches in prolonging material utilization of a product in the early stage of design. DFR focus on harmonizing product design with the recycling practices in order to minimize the loss of valuable materials and preventing unnecessary waste streams at the end of product’s life. In turn, it limits the usage of natural resources.To implement DFR, designers are faced with the challenge of compromising different design objectives such as cost, functional or technical requirements and product’s recyclability performance. This paper attempts to propose an intelligent approach that could facilitate designers to make an easy and quick recyclability assessment as well as selecting recyclable materials integrated with computer aided design. In this paper, the use of fuzzy inference system and genetic algorithm is proposed to optimize the multi-objective problem in the selection of recyclable materials. Case study on the actual conceptual design using computer aided design environment is demonstrated and showing that the proposed method successfully can be applied concurrently during product design. Comparison of proposed method with Sustainability Express Solid Work is also presented. The proposed method can assist product designers to design a high recyclability product without ignoring technical perspectives.     

并行产品设计人员学习与交流能力对下游活动影响的研究

设计人员的学习与交流能力是影响并行产品开发的重要因素.为了研究设计人员学习与交流能力对下游设计活动的影响,构建了学习知识量函数与返工率函数,提出了下游设计活动启动时刻与设计活动间信息交流次数的数学模型,研究了设计人员学习与交流能力对下游设计活动启动时刻及设计活动间信息交流次数的影响,得出了下游设计活动启动时刻与设计活动间信息交流次数的判断条件,并通过实例对判断条件进行了分析验证.根据判断条件以及设计人员学习与交流能力指数,计算出下游设计活动启动时刻与设计活动间信息交流次数.研究结果为缩短产品开发时间与减少产品开发成本提供了理论参考.     

民用航空发动机全生命周期全链路测量管理体系建设研究

为打破传统计量保障仅关注测量设备准确性而非测量结果可靠性的局限,构建了适用于民用航空 发动机全链路的测量过程控制管理体系。该体系以提升测量数据质量为目的,覆盖从部件设计到整机试验,从 适航取证到客户交付所涉及的全部产品测量过程。在测量过程设计阶段,根据测量需求及过程的关重程度,分 析测量能力,导出测量质量要求。在测量过程控制阶段,根据不确定度分析结果,锁定不确定度来源,利用测 量系统分析、控制图、测量能力审核等手段监控测量过程。在测量有效性验证阶段,结合科研阶段航空发动机 测量过程特点,建立同族测量过程归集,通过测量不确定度评定实现质量验证。该体系初期应用于厂内装配执 行过程“高压压气机转子装配”项目的测量分级、能力分析、过程监控、结果验证等,对实现包括试验验证、 生产制造等过程的全部相关方测量过程管理具有借鉴意义。     

基于遗传神经网络的产品配色设计

由于科技的进步和消费者意识的提高,加快了产品的生命周期,如何帮助设计师掌握消费者的感觉,提高产品创新的时效性,是一个不容忽视的问题。从感性工学的理论和知识出发,将目标产品(电话计费器)划分为色块的组合构成,以配色理论制作配色意象问卷,运用倒传递类神经网络学习的特性模拟配色意象评价模式,再通过遗传算法调适与更新的特性搜寻最符合需求意象的配色组合。研究结果显示：通过实验,依据类神经学习与遗传演算推演出的配色组合方式,最终可以架构系统而得以顺利执行,并且提供配色子代的样本作为建议。由本研究的结果可建立一个评估色彩感性的决策支持系统,藉以加快设计流程,辅助设计师以比较有效率且客观的方式进行产品色彩设计。由于科技的进步和消费者意识的提高,加快了产品的生命周期,如何帮助设计师掌握消费者的感觉,提高产品创新的时效性,是一个不容忽视的问题。从感性工学的理论和知识出发,将目标产品(电话计费器)划分为色块的组合构成,以配色理论制作配色意象问卷,运用倒传递类神经网络学习的特性模拟配色意象评价模式,再通过遗传算法调适与更新的特性搜寻最符合需求意象的配色组合。研究结果显示：通过实验,依据类神经学习与遗传演算推演出的配色组合方式,最终可以架构系统而得以顺利执行,并且提供配色子代的样本作为建议。由本研究的结果可建立一个评估色彩感性的决策支持系统,藉以加快设计流程,辅助设计师以比较有效率且客观的方式进行产品色彩设计。     

Conflict mitigation in collaborative design

Conflict management is an unavoidable stage of the collaborative design process. We assume that classifying conflict causes can help conflict prevention as well as detection and resolution strategies. Our approach proposes a crossed classification of conflict causes and the correspondent mitigation strategies and implements this classification in order to enable conflict detection in the earlier phases of the design process. Emphasis is put on capture and use of design rationale and knowledge to help conflict mitigation. Based on this approach, a conflict mitigation module integrated in an advanced architecture for concurrent design and manufacturing is presented. A case study on the design of an electric connector illustrates the use of this module.     

Optimal design of composite shells based on minimum weight and maximum feasibility robustness

A robust design optimization (RDO) approach for minimum weight and safe shell composite structures with minimal variability into design constraints under uncertainties is proposed. A new concept of feasibility robustness associated to the variability of design constraints is considered. So, the feasibility robustness is defined through the determinant of variance–covariance matrix of constraint functions introducing in this way the joint effects of the uncertainty propagations on structural response. A new framework considering aleatory uncertainty into RDO of composite structures is proposed. So, three classes of variables and parameters are identified: deterministic design variables, random design variables and random parameters. The bi-objective optimization search is performed using on a new approach based on two levels of dominance denoted by Co-Dominance-based Genetic Algorithm (CoDGA). The use of evolutionary concepts together sensitivity analysis based on adjoint variable method is a new proposal. The examples with different sources of uncertainty show that the Pareto front definition depends on random design variables and/or random parameters considered in RDO. Furthermore, the importance to control the uncertainties on the feasibility of constraints is demonstrated. CoDGA approach is a powerfully tool to help designers to make decision establishing the priorities between performance and robustness.     

变速箱结构设计专家系统技术的研究

结构设计是机械产品设计过程中的重要环节，解决结构设计的智能化不但可以缩短产品的设计周期，而且还可以降低成本，提高设计质量。专家系统是解决智能化设计的技术之一。本文讨论有关结构专家系统的几个关键技术，主要包括系统的控制策略，面积对象的知识表达方式及结构设计的并行设计     

Exploring the geometry and material space in gear design

Gear design is a complex process. When new materials and manufacturing processes are introduced, traditional empirical knowledge is unavailable and considerable effort is required to find starting design concepts. This forces gear designers to go beyond the traditional standards-based design methods. The method presented here, the concept exploration method, is based on the compromise decision support problem and is demonstrated for gear design which requires the simultaneous exploration of geometry, material and manufacturing spaces to exploit synergies. The results obtained are in agreement with existing knowledge. To further develop design guidelines, ternary contour plots of goal achievement are created to show the interdependence among various design goals. These ternary charts help gear designers to visualize and understand the complexity and compromises involved and help them to make trade-offs among individual goals.     

Heuristic guidelines to support conceptual design

The creativity or unforeseeable nature of the design process, especially during the conceptual phase, makes it difficult to apply current design methodologies to aid designers and help them to reach a conceptual solution in an effective manner. In this paper we present some guidelines, based on experimental data about the evolution of the design process, with which to improve the effectiveness of the conceptual phase, above all as regards finding solutions. Here, effectiveness is taken as meaning quickly reaching a design solution that satisfies the requirements of the problem. Some of the guidelines obtained allow the effectiveness of a designer or a group of designers to be enhanced and are oriented towards controlling the divergence and convergence of the design space. Some guidelines for the development of interactive computer systems to aid designers are also put forward.     

An approach to conceptual and embodiment design within a new product development lifecycle framework

The design of new innovative products is the result of an accurate and precise management of knowledge sources all over its life cycle, such as technology, market, competitors and suppliers. The work contributes with a framework that shows how the knowledge sources influence in the state-of-the-art and market needs so that they become opportunities for innovating products addressing the whole product life cycle. It provides a systematic path from the early generation of ideas to the production of a new product proposal. Through a deep analysis of previous research works of new product innovation life cycle development frameworks and linking it with knowledge management, strategic planning and scorecards, we came out with a structured contribution. The result considers the concurrent activities and its relationships all the way through the product life cycle that can help in creativity and innovation, combined with a process management proposal. Managing the sources of knowledge in highly dynamic markets and technologies is one of the major difficulties involved in innovative products design and development. The emerging knowledge from external sources is confronted with organisation internal knowledge and experience in order to achieve the first product correct.     

A structured procedure for analysis and design of order pick systems

We present a structured procedure for order pick system (OPS) analysis and design that has been established on literature review and interviews with and presentations to OPS experts. In particular, we attempt to include the thinking processes that occur between OPS designers and owners. The design procedure and related issues are discussed in the order of input, selection, and evaluation stages.     

Expert System for Product Manufacturability and Cost Evaluation

Product design is an important stage in the product development cycle. A large proportion of a product's cost is governed by product design. Every effort should be made to ensure a product is “rightly designed for manufacture” at the design stage in order to avoid unnecessary expenditure of time and money in production resulting from a need for redesign. An evaluation tool in the form of an expert system has been developed for product designers to assess manufacturability of product designs. This paper describes the mode of operation in the development of the expert system from which manufacturing information such as selection of processes and materials, and estimation of cost can be obtained. The system enables product designers to evaluate product design alternatives by comparing the analyzed results to come up with the optimum design that best satisfies the requirements. The developed system runs on the PC platform.     

以价值主张为中心的服务设计领结模型——基于双钻石流程的思考

目的 双钻石模型作为常用的服务设计流程,在定义阶段需对前期发现的问题进行聚焦,对设计师的经验和能力有较高要求。探索是否有工具可以帮助设计师更准确地完成服务定义,从而更好地引导后期的设计展开。方法 在双钻石流程中引入价值主张设计环节,提出服务设计“领结模型”,并通过关注社会福祉的“春墅”社区康养服务设计案例说明设计过程。结论 加入了价值主张设计环节的“领结模型”,能够帮助设计师进行更有效的问题聚焦与设计方向制定,从而减少服务设计流程中发展和迭代阶段的不确定性。     

EXPERT SYSTEM FOR PRODUCT MANUFACTURABILITY AND COST EVALUATION

Product design is an important stage in the product development cycle. A large proportion of a product's cost is governed by product design. Every effort should be made to ensure a product is “rightly designed for manufacture” at the design stage in order to avoid unnecessary expenditure of time and money in production resulting from a need for redesign. An evaluation tool in the form of an expert system has been developed for product designers to assess manufacturability of product designs. This paper describes the mode of operation in the development of the expert system from which manufacturing information such as selection of processes and materials, and estimation of costs can be obtained. The system enables product designers to evaluate product design alternatives by comparing the analyzed results to come up with the optimum design which best satisfies the requirements. The developed system runs on the PC platform.