How accurate should early design stage power/performance tools be? A case study with statistical simulation

2004 ◽  
Vol 73 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Lieven Eeckhout ◽  
Koen De Bosschere
2013 ◽  
Vol 32 ◽  
pp. 112-124 ◽  
Author(s):  
Weilin Shen ◽  
Xiaoling Zhang ◽  
Geoffrey Qiping Shen ◽  
Terrence Fernando

Author(s):  
Srikanth Devanathan ◽  
Pranav Koushik ◽  
Fu Zhao ◽  
Karthik Ramani

The issue of environmental sustainability, which is unprecedented in both magnitude and complexity, presents one of the biggest challenges faced by modern society. Engineers, including mechanical engineers, can make significant contribution to the development of solutions to this problem by designing products and processes that are more environmentally sustainable. It is critical that engineers take a paradigm shift of product design i.e. from cost and performance centered to balance of economic, environmental, and societal consideration. Although there have been quite a few design for environment (DfE, or ecodesign) tools developed, so far these tools have only achieved limited industrial penetration: they are either too qualitative/subjective to be used by designers with limited experiences, or too quantitative, costly and time consuming and thus cannot be used during the design process specially during the early design stage. This paper develops a novel, semi-quantitative ecodesign tool that targets specially on early design process. The new tool is a combination of environmental life cycle assessment, working knowledge model, and visual tools such as QFD, functional-component matrix, and Pugh chart. Redesign of staplers is selected as a case study to demonstrate the use of the proposed tool. Efforts are on going to confirm that the new design generated using this new tool does have improved environmental performance.


Author(s):  
Luming Shang ◽  
Giovanni C. Migliaccio

AbstractThe design–build (DB) project delivery method has been used for several decades in the US construction market. DB contracts are usually awarded on the basis of a multicriteria evaluation, with price as one of the most salient criteria. To ensure the project’s success, an owner usually has to invest enough time and effort during scoping and early design to define a program, scope, and budget, ready for procurement and price generation. However, this process can become a burden for the owner and may lengthen the project development duration. As an alternative to the traditional DB, the progressive design–build (PDB) approach permits the selection of the DB team prior to defining the project program and/or budget. PDB has the advantage of maintaining a single point of accountability and allowing team selection based mainly on qualifications, with a limited consideration of price. Under PDB, the selected team works with the project stakeholders during the early design stage, while helping the owner balance scope and budget. However, the key to the effectiveness of PDB is its provision for the ongoing and complete involvement of the owner in the early design phase. Due to the differences between PDB and the other project delivery methods (e.g., traditional DB), project teams must carefully consider several factors to ensure its successful implementation. The research team conducted a case study of the University of Washington’s pilot PDB project to complete the West Campus Utility Plant (WCUP). This paper carefully explores and summarizes the project’s entire delivery process (e.g., planning, solicitation, design, and construction), its organizational structures, and the project performance outcomes. The lessons learned from the WCUP project will contribute to best practices for future PDB implementation.


Author(s):  
Ruirui Chen ◽  
Yusheng Liu ◽  
Xiaoping Ye

Model Based Systems Engineering (MBSE) is a mainstream methodology for the design of complex systems. Verification is a necessary part of MBSE. Although there is significant past research on verification, some deficiencies still exist, such as behavior requirement verification in the early design stage is lacking. In this study, behavior verification at the early design stage is presented. First, a unified modeling method based on SysML is proposed and some transformation rules are defined to ensure the correctness and definiteness of the ontology generation. Second, behavior requirements are classified and formalized as rules. Finally, a hierarchical behavior verification approach based on ontology reasoning is proposed. This approach is convenient for designers to use and no additional expertise is needed. A case study is provided to demonstrate its effectiveness.


Author(s):  
Sachin S. Terdalkar ◽  
Joseph J. Rencis

In this work a new graphically driven interactive stress reanalysis finite element technique has been developed so that an engineer can easily carry out manual geometric changes in a machine element during the early design stage. The interface allow an engineer to model a machine element in the commercial finite element code ANSYS® and then modify part geometry graphically to see instantaneous graphical changes in the stress and displacement contour plots. A reanalysis technique is used to enhance the computational performance for solving the modified problem; with the aim of obtaining results of acceptable accuracy in as short a period of time in order to emphasize the interactive nature of the design process. Two case studies are considered to demonstrate the effectiveness of the prototype graphically driven reanalysis finite element technique. The finite element type considered is a plane stress four-node quadrilateral based on a homogenous, isotropic, linear elastic material. Each case study considered multiple redesigns. A combined approximation reanalysis method is used to solve each redesigned problem. The first case study considers a plate with a hole with the goal to determine the hole shape that will minimize the stress concentration. The second case study considers a support bracket. The goal is to design the cantilever portion of the bracket to have uniform strength and to minimize the stress concentration at the fillet.


2017 ◽  
Vol 34 (3) ◽  
pp. 378-394 ◽  
Author(s):  
Mahmoud Awad ◽  
Yassir A. Shanshal

Purpose The purpose of this paper is to propose a new framework for early design stage utilizing the benefits of Kaizen events, and Design for Six Sigma (DFSS) methodology. To gain a better understanding of the proposed method, a case study of a diesel engine development was presented where the proposed methodology was followed. Design/methodology/approach This paper proposes a hybrid Kaizen DFSS methodology consisting of four Kaizen milestone events with pre-work preceding these events. The events are in line with the four phases of DFSS methodology (define, characterize, optimize, and verify). Findings In order for the proposed method to succeed, few key enablers should be available such as management buy-in and support, effective resources utilization, and proper planning. However, this methodology should be utilized for key projects where criticality is high and deadlines are nearby. Practical implications As proved by two projects, one of them is presented in this paper; the use of the proposed methodology is effective and can bring significant positive changes to an organization. Originality/value Although Kaizen is an old and well-known process, it is to the best of the author’s knowledge that Kaizen has not been utilized in the early design stages of new product development projects. In this paper, a hybrid methodology combining traditional DFSS systematic approach conducted using Kaizen improvement events is proposed and supported by a real-life case study.


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