Abstract: In this paper we report on an in-depth study of engineering design processes. Specifically, we extend our previous research on engineering student design processes to compare the design behavior of students and expert engineers. Nineteen experts from a variety of engineering disciplines and industries each designed a playground in a lab setting, and gave verbal reports of their thoughts during the design task. Measures of their design processes and solution quality were compared to pre-existing data from 26 freshmen and 24 seniors. The experts spent significantly more time on the task overall and in each stage of engineering design, including significantly more time problem scoping. The experts also gathered significantly more information covering more categories. Results support the argument that problem scoping and information gathering are major differences between advanced engineers and students, and important competencies for engineering students to develop. Timeline representations of the expert designers' processes illustrate characteristic distinctions we found and may help students gain insights into their own design processes.

Abstract: Customization and market uncertainty require increased functional and physical bandwidth in product platforms. This paper presents a platform design process in response to such future uncertainty. The process consists of seven iterative steps and is applied to an automotive body-in-white where 10 out of 21 components are identified as potential candidates for embedding flexibility. The paper shows how to systematically pinpoint and value flexible elements in platforms. This allows increased product family profit despite uncertain variant demand, and specification changes. We show how embedding flexibility suppresses change propagation and lowers switching costs, despite an increase of 34% in initial investment for equipment and tooling. Monte Carlo simulation results of 12 future scenarios reveal the value of embedding flexibility.

Abstract: The paper describes the recent state of the art in hierarchical analog synthesis, with a strong emphasis on associated techniques for computer-aided model generation and optimization. Over the past decade, analog design automation has progressed to the point where there are industrially useful and commercially available tools at the cell level-tools for analog components with 10-100 devices. Automated techniques for device sizing, for layout, and for basic statistical centering have been successfully deployed. However, successful component-level tools do not scale trivially to system-level applications. While a typical analog circuit may require only 100 devices, a typical system such as a phase-locked loop, data converter, or RF front-end might assemble a few hundred such circuits, and comprise 10 000 devices or more. And unlike purely digital systems, mixed-signal designs typically need to optimize dozens of competing continuous-valued performance specifications, which depend on the circuit designer's abilities to successfully exploit a range of nonlinear behaviors across levels of abstraction from devices to circuits to systems. For purposes of synthesis or verification, these designs are not tractable when considered "flat." These designs must be approached with hierarchical tools that deal with the system's intrinsic design hierarchy. This paper surveys recent advances in analog design tools that specifically deal with the hierarchical nature of practical analog and RF systems. We begin with a detailed survey of algorithmic techniques for automatically extracting a suitable nonlinear macromodel from a device-level circuit. Such techniques are critical to both verification and synthesis activities for complex systems. We then survey recent ideas in hierarchical synthesis for analog systems and focus in particular on numerical techniques for handling the large number of degrees of freedom in these designs and for exploring the space of performance tradeoffs early in the design process. Finally, we briefly touch on recent ideas for accommodating models of statistical manufacturing variations in these tools and flows

Abstract: Designing modular products can result in many benefits to both manufacturers and consumers. The development of modular products requires the identification of highly interactive groups of elements and arranging (i.e., clustering) them into modules. However, no rigorous clustering technique can be found in engineering design literature. This paper uses the design structure matrix (DSM) to visualize the product architecture and to develop the basic building blocks required for the identification of product modules. The DSM architectural representation and building blocks are then used for the development of a new clustering method based on the minimum description length (MDL) principle and a simple genetic algorithm (GA). The new method is capable of partitioning the product architecture into a set of modules where interactions within modules are maximized and interactions outside modules are minimized. We demonstrate the proposed clustering method using several examples of real complex products and compare our results to clustering arrangements proposed by human experts. The proposed method is capable of mimicking the clustering preference of human experts and yields competitive clustering arrangements.

Abstract: This paper describes an approach for reusing engineering design knowledge. Many previous design knowledge reuse systems focus exclusively on geometrical data, which is often not applicable in early design stages. The proposed methodology provides an integrated design knowledge reuse framework, bringing together elements of best practice reuse, design rationale capture and knowledge-based support in a single coherent framework. Best practices are reused through the process model. Rationale is supported by product information, which is retrieved through links to design process tasks. Knowledge-based methods are supported by a common design data model, which serves as a single source of design data to support the design process. By using the design process as the basis for knowledge structuring and retrieval, it serves the dual purpose of design process capture and knowledge reuse: capturing and formalising the rationale that underpins the design process, and providing a framework through which design knowledge can be stored, retrieved and applied. The methodology has been tested with an industrial sponsor producing high vacuum pumps for the semiconductor industry.

Abstract: The paper describes the recent state of the art in hierarchy. This paper surveys recent advances in analog design tools that specifically deal with the hierarchical nature of practical analog and RF systems. We begin with a detailed survey of algorithmic techniques for automatically extracting a suitable nonlinear macromodel from a device-level circuit. Such techniques are critical to both verification and synthesis activities for complex systems. We then survey recent ideas in hierarchical synthesis for analog systems and focus in particular on numerical techniques for handling the large number of degrees of freedom in these designs and for exploring the space of performance tradeoffs early in the design process. Finally, we briefly touch on recent ideas for accommodating models of statistical manufacturing variations in these tools and flows.

Abstract: Compared with the traditional sequential design method, concurrent engineering is a systematic approach to integrate concurrent design of products and their related processes. One of the key factors to successfully implement concurrent engineering is information technology. In order to design a product and its manufacturing process simultaneously, information on product features, manufacturing requirements, and customer demands must be processed while the design is concurrently going on. There is an increased understanding of the importance of the correct decisions being made at the conceptual design and development stages that involve many complex evaluation and decision-making tasks. In order to promote the efficiency in concurrent product development, appropriate evaluation and decision tools need to be provided. In this paper, the characteristics of fuzzy, multi-stage evaluation and decision making in concurrent product development process are analyzed and a decision support system for product design in concurrent engineering is presented. An example is given to illustrate the application of the system.

Abstract: This book summarizes advances in a number of fundamental areas of optimization with application in engineering design The selection of the 'best' or 'optimum' design has long been a major concern of designers and in recent years interest has grown in applying mathematical optimization techniques to design of large engineering and industrial system

Abstract: In this paper we present a user-centered design approach to the development of a Virtual Environment (VE), by utilizing an iterative, user-informed process throughout the entire design and development cycle. A preliminary survey was first undertaken with end users, that is, architects, chief engineers, and decision makers of a real-world architectural and urban planning project, followed by a study of the traditional workflow employed. We then determined the elements required to make the VE useful in the real-world setting, choosing appropriate graphical and auditory techniques to develop audiovisual VEs with a high level of realism. Our user-centered design approach guided the development of an appropriate interface and an evaluation methodology to test the overall usability of the system. The VE was evaluated both in the laboratory and, most importantly, in the users' natural work environments. In this study we present the choices we made as part of the design and evaluation methodologies employed, which successfully combined research goals with those of a real-world project. Among other results, this evaluation suggests that involving users and designers from the beginning improves the effectiveness of the VE in the context of the real world urban planning project. Furthermore, it demonstrates that appropriate levels of realism, in particular spatialized 3D sound, high-detail vegetation, and shadows, as well as the presence of rendered crowds, are significant for the design process and for communicating about designs; they enable better appreciation of overall ambience of the VE, perception of space and physical objects, as well as the sense of scale. We believe this study is of interest to VE researchers, designers, and practitioners, as well as professionals interested in using VR in their workplace.

Abstract: Over the last decade, Computer Aided Engineering (CAE) tools have become essential in the assessment and optimization of the acoustic characteristics of products and processes. The possibility of evaluating these characteristics on virtual prototypes at almost any stage of the design process reduces the need for very expensive and time consuming physical prototype testing. However, despite their steady improvements and extensions, CAE techniques are still primarily used by analysis specialists. In order to turn them into easy-to-use, versatile tools that are also easily accessible for designers, several bottlenecks have to be resolved. The latter include, amongst others, the lack of efficient numerical techniques for solving system-level functional performance models in a wide frequency range. This paper reviews the CAE modelling techniques which can be used for the analysis of time-harmonic acoustic problems and focusses on techniques which have the Trefftz approach as baseline methodology. The basic properties of the different methods are highlighted and their strengths and limitations are discussed. Furthermore, an overview is given of the state-of-the-art of the extensions and the enhancements which have been recently investigated to enlarge the application range of the different techniques. Specific attention is paid to one very promising Trefftz-based technique, which is the so-called wave based method. This method has all the necessary attributes for putting a next step in the evolution towards truly virtual product design.

Abstract: INTRODUCTION Introduction Outline of and Structure Designing Why Manual for Design Engineering? Hypothesis, Theory, Science System Products, Processes, Technical Systems - Results from Design Engineering and Manufacturing Information, Knowledge, Data Technical Object and Process System Design Engineering, Engineering Design Process Engineering Design System - Structure Engineering Design Process (DesP) Engineering Design Science ESTABLISHING PROPERTIES OF DESIGNED TECHNICAL SYSTEMS Engineering Design Processes - Case Examples KNOWLEDGE RELATED TO ENGINEERING DESIGN PROCESSES Engineering Design System (DesS) and Engineering Design Processes (DesP) Design Situation Procedural Model of Design Engineering KNOWLEDGE RELATED TO DESIGNED TECHNICAL SYSTEMS Transformation System, Including Transformation Process, Technical Process, and Technical System Technical (Object) Systems Specialized Engineering Design Sciences, Specialized Theories of Technical Systems SUPPORT FOR DESIGN ENGINEERING Design Methods Information and Formal Support for Design Engineering Technical Support for Design Engineering Human Resources, Management and Environmental Support for Design Engineering META-KNOWLEDGE RELATED TO DESIGN ENGINEERING Engineering Design Science APPENDIX - Glossary REFERENCES

Abstract: This article presents a modified version of the differential evolution algorithm to solve engineering design problems. The aim is to allow each parent vector in the population to generate more than one trial (child) vector at each generation and therefore to increase its probability of generating a better one. To deal with constraints, some criteria based on feasibility and a diversity mechanism to maintain infeasible solutions in the population are used. The approach is tested on a set of well-known benchmark problems. After that, it is used to solve engineering design problems and its performance is compared with those provided by typical penalty function approaches and also against state-of-the-art techniques.

Abstract: In this paper, it is discussed how knowledge based engineering has been exploited to develop a flexible design system, able to integrate a heterogeneous set of distributed discipline-specific design and analysis tools into a modular design framework. This system, called Design and Engineering Engine (DEE), demonstrated its capability to support designers in performing what-if studies and accelerate Multi-disciplinary Design and Optimisation (MDO), through the automation of those lengthy and repetitive activities typically hampering the design process. Design quality and innovation are also supported by enabling the use of high fidelity analysis tools in the early design phase.

Abstract: The interaction of heterogenous control hard and software plays a key role in enabling mechatronic production systems to become flexible and agile systems. Nevertheless, control software engineering still tends to be the last step within the development process. To a large extent it is carried out during the commissioning phase of the production ramp-up. On the first hand this leads to a loss of time and quality as well as to a loss of reputation and future orders on the second hand. A method that is referred to as Virtual Commissioning tries to overcome this situation. The aim is to enable control software engineering to, both take over the initiative in system design and to perform important activities earlier in the design process of production equipment. In this paper, the technological and economical scalability of Virtual Commissioning is analyzed. Based on the analysis, a technical concept for a scalable simulation environment is presented. The paper concludes with a new method for the economic application of Virtual Commissioning.

Abstract: Because of the increasing complexity of products and the design process, as well as the popularity of computer-aided documentation tools, the number of electronic and textual design documents being generated has exploded. The availability of such extensive document resources has created new challenges and opportunities for research. These include improving design information retrieval to achieve a more coherent environment for design exploration, learning, and reuse. One critical issue is related to the construction of a structured representation for indexing design documents that record engineers' ideas and reasoning processes for a specific design. This representation should explicitly and accurately capture the important design concepts as well as the relationships between these concepts so that engineers can locate their documents of interest with less effort. For design information retrieval, we propose to use shallow natural language processing and domain-specific design ontology to automatically construct a structured and semantics-based representation from unstructured design documents. The design concepts and relationships of the representation are recognized from the document based on the identified linguistic patterns. The recognized concepts and relationships are joined to form a concept graph. The integration of these concept graphs builds an application-specific design ontology, which can be seen as the structured representation of the content of the corporate document repository, as well as an automatically populated knowledge base from previous designs. To improve the performance of design information retrieval, we have developed ontology-based query processing, where users' requests are interpreted based on their domain-specific meanings. Our approach contrasts with the traditionally used keyword-based search. An experiment to test the retrieval performance is conducted by using the design documents from a product design scenario. The results demonstrate that our method outperforms the keyword-based search techniques. This research contributes to the development and use of engineering ontology for design information retrieval.

Abstract: This study discusses a methodology for integrating Design for Environment (DfE) and life cycle assessment (LCA) techniques both into new product development and into the process of redesigning a set of existing products. The article explains the reasons for developing DfE in general, and pays particular attention to a specific, chosen product, a class of electrical distribution boards, to illustrate the concept. The main process steps in the development of the DfE are outlined, and the development of a LCA that satisfies the requirements of the ISO 14040 standard is illustrated. A major benefit of the DfE methodology proposed in this work is the possibility to use LCA data both during new product development and when modifying old products, with the aim of continuously reducing the overall environmental impact of products during their life cycle. This improvement cycle begins with the attempt to find new design solutions (for assembly and set-up in the case of electrical distribution boards), continues wi...

Abstract: Using FPGAs, a designer can separate the design process from the manufacturing flow. Therefore, the owner of a sensitive design need not expose the design to possible theft and tampering during its manufacture, dramatically simplifying the process of assuring trust in that design. Modern FPGAs include bitstream security features that turn the fielded design trust problem into an information security problem, with well-known cryptographic information security solutions. The generic nature of the FPGA base array allows the validation expense to be amortized over all designs targeted to that base array. Even the task of checking design tools is simplified by using non-destructive checks of the FPGA design.

Abstract: Introducing a new engineering product or changing an existing model involves developing designs, reaching economic decisions, selecting materials, choosing manufacturing processes, and assessing environmental impact. These activities are interdependent and should not be performed in isolation from each other. This is because the materials and processes used in making a product can have a major influence on its design, cost, and performance in service. This Fourth Edition of the best-selling Materials and Process Selection for Engineering Design takes all of this into account and has been comprehensively revised to reflect the many advances in the fields of materials and manufacturing, including: Increasing use of additive manufacturing technology, especially in biomedical, aerospace and automotive applications Emphasizing the environmental impact of engineering products, recycling, and increasing use of biodegradable polymers and composites Analyzing further into weight reduction of products through design changes as well as material and process selection, especially in manufacturing products such as electric cars Discussing new methods for solving multi-criteria decision-making problems, including multi-component material selection as well as concurrent and geometry-dependent selection of materials and joining technology Increasing use of MATLAB by engineering students in solving problems This textbook features the following pedagogical tools: New and updated practical case studies from industry A variety of suggested topics and background information for in-class group work Ideas and background information for reflection papers so readers can think critically about the material they have read, give their interpretation of the issues under discussion and the lessons learned, and then propose a way forward Open-book exercises and questions at the end of each chapter where readers are evaluated on how they use the material, rather than how well they recall it, in addition to the traditional review questions Includes a solutions manual and PowerPoint lecture materials for adopting professors Aimed at students in mechanical, manufacturing, and materials engineering, as well as professionals in these fields, this book provides the practical know-how in order to choose the right materials and processes for development of new or enhanced products.

Abstract: Computational models with variable fidelity have been widely used in engineering design. To alleviate the computational burden, surrogate models are used for optimization without recourse to expensive high-fidelity simulations. In this work, a model fusion technique based on Bayesian Gaussian process modeling is employed to construct cheap, surrogate models to integrate information from both low-fidelity and high-fidelity models, while the interpolation uncertainty of the surrogate model due to the lack of sufficient high-fidelity simulations is quantified. In contrast to space filling, the sequential sampling of a high-fidelity simulation model in our proposed framework is objective-oriented, aiming for improving a design objective. Strategy based on periodical switching criteria is studied which is shown to be effective in guiding the sequential sampling of a high-fidelity model towards improving a design objective as well as reducing the interpolation uncertainty. A design confidence (DC) metric is proposed to serves as the stopping criterion to facilitate design decision making against the interpolation uncertainty. Numerical and engineering examples are provided to demonstrate the benefits of the proposed methodology.

Abstract: Environmental conditions have a significant effect on the performance of both flexible and rigid pavements. External factors such as precipitation, temperature, freeze-thaw cycles, and depth to water table play a key role in defining the bounds of the impact the environment can have on the pavement performance. As part of the new US Mechanistic-Empirical Pavement Design Guide (MEPDG) being developed under the overall project sponsored by the National Cooperative Highway Research Program (NCHRP project 1–37A), a climatic modelling tool called the Enhanced Integrated Climatic Model (EICM) was implemented to incorporate the changes in temperature and moisture of unbound materials into the design process. Currently a new independent review project (NCHRP 1–40) is reviewing this model to correct errors and to develop further enhancements to produce a final methodology ready for approval/disapproval vote by AASHTO in 2006. This paper reflects the methodology used for the MEPDG and present the models in...

Abstract: This paper deals with topology optimization of load carrying structures defined on a discretized design domain where binary design variables are used to indicate material or void in the various finite elements. The main contribution is the development of two iterative methods which are guaranteed to find a local optimum with respect to a 1-neighbourhood. Each new iteration point is obtained as the optimal solution to an integer linear programming problem which is an approximation of the original problem at the previous iteration point. The proposed methods are quite general and can be applied to a variety of topology optimization problems defined by 0-1 design variables. Most of the presented numerical examples are devoted to problems involving stresses which can be handled in a natural way since the design variables are kept binary in the subproblems.

Abstract: This paper describes a methodology for developing ontologies for engineering design. The methodology combines a number of methods from social science and computer science, together with taxonomies developed in the field of engineering design. A case study is used throughout the paper focusing upon the use of an ontology for searching, indexing and retrieving of engineering knowledge. An ontology for indexing design knowledge can assist the users to formulate their queries when searching for engineering design knowledge. The root concepts of the ontology were elicited from engineering designers during an empirical research study. These formed individual taxonomies within the ontology and were validated through indexing a set of ninety-two documents. Relationships between concepts are extracted as the ontology is populated with instances. The identified root concepts were found to be complete and sufficient for the purpose of indexing. A thesaurus and an automatic classification are being developed as a result of this evaluation. The methodology employed during the test case is presented in this paper. There are six separate stages, which are presented together with the research methods employed for each stage and the evaluation of each stage. The main contribution of this research is the development of a methodology to allow researchers and industry to create ontologies for their particular purpose and to develop a thesaurus for the terms within the ontology. The methodology is based upon empirical research and hence, focuses upon understanding a user’s domain models as opposed to extracting an ontology from documentation.Copyright © 2005 by ASME

Abstract: The purpose of this paper is to describe a new approach to process the data points measured from turbine blade airfoils in order to make a valid shape via reverse engineering method. Currently, preliminary B-rep models can be created by fitting surfaces to point clouds using a 3D laser scanner. In case of a turbine blade, due to high shape complexity, the resulting model is often unsuitable in practice. A small change in blade geometry can lead to a large change in turbine performance. Therefore, control of the blade shape is critical to the design process. Authors believe that the only way to capture the valid shape of a blade airfoil out of the many manufacturing deviations is to incorporate design key-points during reverse engineering. Implementation of the new method using segmentation and constrained fitting algorithm (SCFA) on a heavy-duty industrial gas turbine blade has been reported and discussed.

Abstract: This paper examines design iteration and its modelling in the simulation of New Product Development (NPD) processes. A framework comprising six perspectives of iteration is proposed and it is argued that the importance of each perspective depends upon domain-specific factors. Key challenges of modelling iteration in process simulation frameworks such as the Design Structure Matrix are discussed, and we argue that no single model or framework can fully capture the iterative dynamics of an NPD process. To conclude, we propose that consideration of iteration and its representation could help identify the most appropriate modelling framework for a given process and modelling objective, thereby improving the fidelity of design process simulation models and increasing their utility.