Using DSM and fmGA to Determine the Optimal Design Process for Engineering Design Projects

Construction design projects are multi-disciplinary requiring input from several players including planners and design professionals. Project managers have developed techniques for planning, organizing, monitoring, and optimizing complex design projects. The Critical Path Method (CPM) is traditionally the most commonly used to address these issues. Various techniques have been added to CPM like splitting the activities to optimize projects duration. However, the CPM approach is based on workflow and is not effective in handling iterations, which is a characteristic of design projects. Also, while CPM can effectively handle sequential and parallel activities, it cannot handle coupled activities. The Design Structure Matrix (DSM) approach represents information flows in addition to workflows in a project. The DSM method can handle sequential, parallel, in addition to coupled activities. The study reported here involves the application of DSM for design projects, and describes an algorithm to optimize planning of design processes. Using DSM and through finding critical activities, management focuses on the essential information transfer requirements in the project, thereby minimizing rework, and improving throughput and design quality.

Multidisciplinary design for construction is a complex and iterative process. Because conventional planning tools cannot model iterations, a matrix-based methodology called design structure matrix (DSM) has been developed. Although this approach has shown the potential to model and manage iterative design processes, there is no widespread application. It has been documented that the formation of the DSM is a key limitation to its practical application. Furthermore, the findings of an action research–based investigation on implementing the DSM approach on multiple construction projects suggested the formation of a drawing-based DSM rather than the conventional activity-based DSM to improve applicability. The study also proposed a structured methodology called design interface management system (diMs) to form the drawing design structure matrix. The objective of this paper is to evaluate the effectiveness of diMs methodology and its implementation on the construction design processes. The testing was conducted through a comparative study of two design cases of a large airport design process. The performance of the design management process of the test group that used diMs was compared with the control group that used existing design management practices. The data for the comparative study were obtained through document and questionnaire–based assessment criteria. The comparison of these assessment criteria shows significant improvements in the design management process for the test group. The basis for these improvements was further evaluated through multiple sources of evidences such as focused interviews, physical visits, open-ended interviews, and participatory observations.

Transfer moulding is the most common process for the encapsulation of electronic packages in semiconductor manufacturing. Quality of the moulding is affected by a large number of mould design parameters and process parameters. Currently, the parameters setting is performed by experienced engineers in a trial and error manner and often the optimal setting can not be obtained. In the face of global competition, the current practice is inadequate. In this research, a process optimisation system for transfer moulding of electronic packages is described which involves design of experiments (DOE) techniques, artificial neural networks (ANNs), multiple regression analysis and the minimax method. The system is aimed to determine the optimal mould design parameters and process parameter settings of transfer moulding of electronic packages for multiobjective problem. Implementation of the optimisation system has demonstrated that the time for the determination of optimal mould design parameters and process parameters setting can be greatly reduced and the parameters setting recommended by the system can contribute to the good quality of moulded packages without relying on experienced engineers.

Tolerancing decisions can profoundly impact the quality and cost of electro-mechanical assemblies. Existing approaches to tolerance analysis and synthesis in design entail detailed knowledge of geometry of the assemblies and are mostly applicable during advanced stages of design, leading to a less than optimal design process. During the design process of assemblies, both the assembly structure and associated tolerance information evolve continuously. Therefore, significant gains can be achieved by effectively using this information to influence the design of the assembly. Motivated by this, we identify and explore two goals for future research that we believe can enhance the scope of tolerancing for the entire design process. The first goal is to advance tolerancing decisions to the earliest possible stages of design. This issue raises the need for effective representation of tolerancing information during different stages of design and for effective assembly modeling. The second goal addresses the appropriate, synergistic use of available methods and best practices for tolerance analysis and synthesis, at successive stages of design. Pursuit of these goals leads to the definition of a multilevel approach that enables tolerancing to be addressed at successive stages of design in an incremental fashion. The resulting design process, which we call the design for tolerance process, integrates three important domains: (1) design activities at successive stages of design; (2) assembly models that evolve continuously through the design process; (3) methods and best practices for tolerance analysis and synthesis. We demonstrate major steps of our proposed approach through a simple, yet illustrative, example.

To ensure efficient knowledge capture, tracing, sharing and reuse to support product design and development, it is important to find a structured way to organize the past experience and information. Design structure matrix (DSM), a structured method which has advantages on representing and analysing interaction relations between system elements (such as development tasks, design parameters, architecture concepts, and organizational teams), is proposed to be suitable means to define, capture and organize and distribute the system level knowledge during the product development process. The captured knowledge through DSM can improve understanding of the design routes and design history by linking designed items to rationales, decisions and assumptions behind them. Meanwhile, the knowledge captured through DSM could assist on predicting changes on existing solutions, reusing of the existing solutions in new projects, and educational process for inexperienced designers. How to capture, trace and manage the design knowledge through DSM is presented in detail, and a DSM-based knowledge management system has been developed.

Tolerancing decisions during the design of electromechanical products profoundly affect cost and quality. Existing approaches to tolerance analysis and synthesis entail detailed knowledge of geometry of the assemblies and are mostly applicable during advanced stages of design, leading to a less than optimal design process. During design, both the assembly structure and associated tolerance information evolve continuously and significant gains can be achieved by effectively using this information to influence the design. We explore two goals of research to expand the scope of tolerancing to the entire design process. The first goal is to advance tolerancing decisions to the earliest possible stages of design. This issue raises the need for effective representation of tolerancing information during early stages. The second goal addresses the appropriate use of industry best practices and efficient computational approaches. Pursuit of these goals leads to the definition of a multilevel approach that enables tolerancing to be addressed at successive stages of design in an incremental, continuous ongoing fashion. The resulting design process, which we call the design-for-tolerance process, integrates three important domains: (1) design activities at successive stages of design; (2) assembly models that evolve continuously through the design process; and (3) methods and best practices for tolerance analysis and synthesis. We demonstrate major steps of our proposed approach through a simple, yet illustrative, example.

A methodology for distributed knowledge modeling will be presented in this article, in order to contribute to a better decision making during design problems analysis. An optimal design process refers to setting up coherent numerical models and it requires a well structured problem definition. However, a lack of downstream information in early stages of product development leads to a complicated elicitation task that became an issue due to nowadays distributed environments. A Multi-Agent approach is proposed to support the distributed knowledge elicitation process. A set of agents will guide members from the distributed design team, throughout the product life cycle, to extract relevant information and analyze it. The interaction among agents will highlight potential incoherencies during the modeling process, in order to enable partners to avoid inconsistent information. A coherent knowledge base is then constructed and ready to be used to create models to be analyzed by traditional inference engines such as optimization solvers, constraint satisfaction programming, etc.

In this paper, an optimal design process for high-rise building structures is presented based on cost-effectiveness criterion. Then, an optimal design of a complex high-rise building based on cost-effectiveness criterion is carried out by using the design process. A minimum life cycle cost and corresponding elastic inter story drift considering initial cost and damage cost as two separate objective functions are obtained by using genetic algorithm. Finally, fitting curves of life cycle cost, initial cost, damage cost and corresponding performance indexes are interpolated by using one-dimensional linear interpolation considering elastic inter story drift ratio as control performance indexes. And lots of life cycle cost designs and corresponding performance indexes of the separated objective function are given. The results show that the optimal design process is practical and optimal results are diverse, and can be chosen flexibly by owners.

An application of the Design Structure Matrix to Integrated Concurrent Engineering

Re-engineering of the design process for concurrent engineering

Earthquake protection of structures with nonlinear viscous dampers optimized through an energy-based stochastic approach

This paper is aimed to propose a design of the Automatic Workpiece Changer (AWC), which will be redesigned from the existing one to reduce the time on design processes. To redesign AWC, Axiomatic design and design constraints are applied. The process composes of 2 phases, i.e., first to decompose the existing design and to represent the Design Matrix (DM) of the product and second to convert the DM to Design Structure Matrix (DSM). The first phase output is the multiple layers of DSM. Then the new task is clarified and the design constraints are considered with the design solution. Lastly, it is step of identifying the future change in the second phase. The process will help the designer to analyze the elements that affect the change, which helps him determine the propriety of the design in the economic aspect. Finally, the result of the study is the future change of AWC which can be modified to suit modules.

Many researchers have highlighted weaknesses of traditional approaches, such as PERT and CPM, in scheduling product development projects and in particular their failure to model iteration. The design structure matrix (DSM) method provides a practical and useful tool to deal with this issue. The advantages of DSM representation and analysis techniques have led to their increasing use in project planning, and have spawn dozens of research efforts on organizing design tasks. This paper explores the nature of DSM approach, and reviews its recent development in design project scheduling. The paper also discusses limitations of existing DSM-based models, and proposes future research directions.

Green buildings have recently become a key aspect of the construction field and bring along a renovation of the whole industry chain. Such changes introduce new challenges for all subjects involved, and designers are also affected by such issues, especially for the development of projects based on international green building standards. Within this scope, project management plays a key role in the optimization of the design phase. This research analyzes the design process of international projects from the project management perspective through a multiple case study approach, considering the sustainability-related tasks that negatively affect the project design development under two types of contractual approaches: Design-Build and Design-Bid-Build. It aims to identify whether the Design-Build or Design-Bid-Build process is the best solution for developing green building projects. Two case studies in Italy and two case studies in Spain are analyzed, and the effects of the project management issues are evaluated under three different points of view: Time, cost, and level of sustainability of the building. A poorly planned process for the achievement of the various green building features of the project can impact the project schedule and the budget, whereas, a poorly managed project could also negatively impact its green building features. Finally, this research also highlights the positive relationship between process integration and green building design development.

This volume is the second edition of Introduction to Optimum Design by Jasbir Arora. It includes several revisions and additions. This edition is among the most comprehensive books available in the optimization approach to design. The author combines his many years of experience in structural optimization in a single volume covering nearly all aspects of optimum design. A new feature in this book is a discussion of such widely available software as Microsoft Excel and MATLAB in solving optimum design problems. Chapter 1 covers the underlying concept of design. This review specifically points to the role of optimization in design and differences between conventional and optimum design. The chapter is especially important in clarifying why one should proceed with the optimization approach in a design process. Chapter 2 is devoted to the basic formulation. More specifically, it discusses establishing design criteria and identifying design attributes. This chapter provides a clear roadmap to assist in setting up a series of optimization goals and constraints in a given problem. Through simple examples, the author defines how a concept can be turned into mathematical formulations in an optimum design process. A reader who is a beginner will find this chapter especially helpful. Chapters 3–11 focus on various methods of optimization. The author starts with graphics solutions Chapter 3 and continues with various methods, including Lagrange multipliers, definitions and the role of constraints, checking for the existence of the optimum solutions Chapters 4 and 5 , linear programming Chapters 6 and 7 , constrained and unconstrained optimum design, and numerical solutions Chapters 8–11 . The flow of information and presentation of various methods in these chapters is coherent and skillfully leads the reader from simple conceptual solutions to more-complicated mathematical solutions and eventually to those requiring numerical computations. These chapters provide a collection of design problems that introduce the reader to the realistic application of various methods. Exercise problems at the end of each chapter will provide ample opportunity to challenge stu-