Quantitative evaluation of product disassembly for recycling

This paper presents a method for evaluating the ease-of-disassembly of products. Its primary use is in designing products for recycling, but it also facilitates consideration of servicing and maintenance, and making environmentally-related decisions. The method is developed and discussed in the context of relatively small products that can be disassembled by a seated person using hand-held tools. The evaluation procedure is centered around a spreadsheet-like chart and uses a catalog of task difficulty scores. The scores were derived from work-measurement analyses of standard disassembly tasks, and provide a means of identifying weaknesses in the design and comparing alternatives quantitatively. The structure of the evaluation chart and the derivation of difficulty scores are explained, followed by a demonstration of analyzing a computer central processing unit. The limitations of the method and future extensions are outlined.     

Concurrent engineering approach in the development of composite products: A review

Concurrent Engineering (CE) is regarded as a systematic design approach which integrates concurrent design of product with the related processes which is able to accomplish product that can be produced at lower cost, shorter time and with higher quality and this achievement was termed as cost, time and quality (CTQ) improvement. Since its establishment, CE philosophy was well implemented in product development with traditional materials such as metals but up to date, the work on CE in composite product development is still limited. Hence, a review on the implementation of Concurrent Engineering (CE) approach in the development of composite products is presented in this paper which includes review of various studies of CE techniques in composite product development. In addition, the relationship between CE and Pugh total design method is discussed in the context of composite design. Moreover, publications related to materials selection, life cycle analysis and sustainability issues of composite materials are also reviewed whereby a section is devoted to highlight previous work on materials selection using Analytical Hierarchy Process method. It was observed that materials selection of composite materials is a very important activity as far as CE in composite product development. The use of various techniques and computer aided materials selection tools such as Analytical Hierarchy Process has helped designers to select the most optimum composite materials for engineering components. Furthermore, based on current trends in composites product development, the role of CE is expected to be more crucial to assist composites designers in achieving the design requirements from various stakeholders effectively and efficiently considering the expanding range of composite materials availability as well as realizing new potential for biocomposites applications through introduction of innovative alternative problem solving methods as part of the CE family.     

Automated manufacturability analysis: A survey

In the market-place of the 21st century, there is no place for traditional over-the-wall communications between design and manufacturing. In order to design it right the very first time, designers must ensure that their products are both functional and easy to manufacture. Software tools have had some successes in reducing the barriers between design and manufacturing. Manufacturability analysis systems are emerging as one such tool — enabling identification of potential manufacturing problems during the design phase and providing suggestions to designers on how to eliminate them.In this paper, we provide a survey of current state-of-the-art automated manufacturability analysis. We present the historical context in which this area has emerged and outline characteristics to compare and classify various systems. We describe the two dominant approaches to automated manufacturability analysis and overview representative systems based on their application domain. We describe support tools that enhance the effectiveness of manufacturability analysis systems. Finally, we attempt to expose some of the existing research challenges and future directions.     

Modelling engineering change management in a new product development supply chain

The changes within a new product development (NPD) process are handled differently depending on the stage of the project. The changes during the initial stages of the project are addressed by design iterations, while the changes after the product design is complete are addressed using a formal engineering change management (ECM) process. The ECM process is a complex process, especially under a collaborative environment, where various independent entities work together for a common cause of product development. The interactions between the NPD and ECM processes have rarely been investigated in the research community. In this paper, we attempt to study the interactions between the various NPD and ECM process parameters by modelling the processes and simulated the model to understand the parameter interactions. The organisations in a supply chain have been characterised based on their interactions with the original equipment manufacturer (OEM) during the NPD process. The organisation process templates representing the NPD and ECM processes of each type of organisation in the supply chain have been modelled. The templates have been used to develop a simulation model representing the NPD and ECM processes for a supply chain. The process variables, such as processing rates, resources, resource composition, resource allocation priority, processing quality and phase overlap, have been included in the model. The results indicate that most of the variables and interactions among the variables have a significant influence on the NPD lead time. By identifying the status of?the NPD process, the decision-makers can use these results to develop appropriate management policies to govern their product development projects.     

面向并行工程的知识管理研究

知识经济和大规模定制等概念的提出,使得企业把知识财富作为获得竞争优势的战略要素来看待,企业知识管理由此受到学术界和企业界的共同关注。知识管理方法和工具集同并行工程现有方法和工具集的结合,产生了一个新的研究和应用领域,作者在跟踪国外研究和并行工程实践经验的基础上,对这一新兴领域的基本内容,实施方法和关键技术作了初步的讨论,以期引起国内学术界和企业界对该领域的关注,促进我国企业形成自己的核心竞争能力。     

A unified product structure management for enterprise business process integration throughout the product lifecycle

Information availability is a key factor for business success and competitive advantage. While created by design engineers, product structure is accessed and referenced by other users involved in product lifecycle from various departments. However, there is a lack of efficient ways of managing product structure information for enterprise business process integration. This study proposes a unified product structure management model to fill in this gap. With this proposed model, the product structure is managed in a unified way and can be accessed by different people with various disciplines in the right formats throughout the entire product lifecycle, including business processes of quotation, sales order processing, design, planning, scheduling, production, and delivery. This research is part of the enterprise business information management system project whose purpose is to streamline the information management for key business processes to integrate multi-disciplines in an enterprise for product development. A prototype system has been implemented to verify the model developed by taking real cases in a mould-manufacturing company. The results show the potential for substantial improvements in industrial competitive advantage.     

Evaluation of materials supply systems during product development projects

The aim of this paper is to analyse how materials supply systems can be evaluated during product development projects in a concurrent engineering context. The focus is on performance assessment of materials supply systems and the input data required. A case study was conducted in close cooperation with a company and two performance measures were assessed during the concept definition phase and recalculated during the product and process validation phase. The results show that preliminary input data can be used to calculate performance measures by means of the following approaches: indicators, standards or scenarios. Furthermore, it is discussed how performance assessment can assist the materials supply systems design process in a concurrent engineering context by facilitating early problem discovery, early decision-making, and common understanding.     

Decision-making support system for human resource allocation in product development projects

Recent dismal economic conditions and a ruthlessly competitive environment have forced many companies to restructure, or reorganize their priorities. For such companies, the concentration of various resources upon their particular corporate strong points has become a central strategy. Consequently, there has been a rapid increase in the importance of (1) selecting profitable projects from a wealth of possible alternatives and (2) optimizing the allocation of current resources among the selected projects. This paper proposes an optimization system for project selection that not only yields the most beneficial project set, but also the optimum allocation of human resources for the selected projects. The optimization system consists of two algorithms, namely (1) a project selection algorithm for choosing the set of projects that maximizes the total estimated profit, and (2) a human resource allocation algorithm for optimally placing human resources among the selected projects, having considered the satisfaction level provided by each employee's skills, personal motivation and career goals.     

面向制造的设计系统中的可制造性评价方法与应用

对面向制造的设计系统中的可制造评价进行了深入地探讨，     

Case studies of coordination activities and problems in collaborative design

The design and engineering of large, complex electromechanical artifacts for use in space requires the integration of many engineering groups, spread across the components of the artifact and across the customer and suppliers. And within each engineering group there is a need to integrate the many diverse skills required, such as electrical, mechanical, thermal, software and materials. This paper describes the results of a study conducted from the Summer of1992 through the Fall of1993 at a medium sized aerospace company. The study had two goals. The first goal was to identify project delays that were due to poor coordination and integration. The second goal was to identify the activities which occupy engineers at the company and to rank the activities by the level of frustration and wasted effort encountered in performing them. The first goal was accomplished by studying25 problem cases, compiled and classified into six problem categories: information acquisition (24% of cases), information access (32% of cases), knowledge access (4% of cases), decision interdependence (8% of cases), activity management (12% of cases) and agent access (16% of cases). The delays associated with information acquisition, information access and knowledge access range from 1 day to as much as a year; they range from 1 day to a week for the other categories. The second goal, to identify the activities which occupy engineers and to rank the activities by the frustration and wasted effort encountered, was accomplished by conducting a survey, circulated to 30 engineers across five different departments. The participants were required to track the time spent in seven different activities over an actual 5 day week. They also estimated the time they would spend on these activities in a typical week on a percentage basis. The percentages of time spent were: information gathering (13.7%—actual; 12.2%—typical), problem, solving/thinking (28.0%—actual; 29.8%—typical), documentation (23.5%—actual; 19.5%—typical), planning (7.8%—actual; 8.5%—typical), negotiating (7.6%—actual; 9.8%—typical), support and consulting (17.1%—actual; 18.1%—typical) and other (2.3%—actual; 2.1%—typical). The participants also rated the activities from 1 (most frustrating) to 7 (least frustrating). The average scores, beginning with the most frustrating, were: 3.33-information gathering, 3.48-negotiation, 3.56-documentation, 3.67-support/consulting, 3.9-planning, 4.52-problem solving/thinking and 6.67-other.     

Information hiding in product development: the design churn effect

Execution of a complex product development project is facilitated through its decomposition into an interrelated set of localized development tasks. When a local task is completed, its output is integrated through an iterative cycle of system-wide integration activities. Integration is often accompanied by inadvertent information hiding due to the asynchronous information exchanges. We show that information hiding leads to persistent recurrence of problems (termed the design churn effect) such that progress oscillates between being on schedule and falling behind. The oscillatory nature of the PD process confounds progress measurement and makes it difficult to judge whether the project is on schedule or slipping. We develop a dynamic model of work transformation to derive conditions under which churn is observed as an unintended consequence of information hiding due to local and system task decomposition. We illustrate these conditions with a case example from an automotive development project and discuss strategies to mitigate design churn.

A method for imprecision management in complex product development

Managing uncertainty levels is important for organizations carrying out complex product development processes since it fosters design process improvements and optimization. Among the different uncertainties, design imprecision is known to represent uncertainty in decision-making that typically triggers changes to the value assigned to design variables during the early stages of the development process. This paper presents a method aiming to support large organizations understanding, quantifying and communicating this type of uncertainty. The imprecision management method that is proposed relies on five main steps: collection of historical records of change, time evolution reconstruction, statistical characterization of the typical levels of imprecision that should be expected, communication to new projects and continuous knowledge update. In addition, we present results from a case-study performed at Rolls–Royce that tested the method’s applicability in practice. The study shed light to interesting empirical findings about the typical level of imprecision in design variables and its evolution during real product development projects. The results from this initial evaluation suggest that the method provides useful support for design process management and thus has industrial value.     

产品开发过程管理系统

分析了PDM系统对产品开发过程管理的基本功能和不足,提出了一种集成产品数据管理和开发过程管理的工作流管理系统,提出了一种以过程活动为核心,集成了产品结构,组织,资源,成本和时间等视图的集成化产品开发过程模型。针对此模型,设计并实现了一个集成工作流建模,工作流执行和产品数据管理的产品开发过程管理系统。     

State-of-the-art technologies and methodologies for collaborative product development systems

In order to facilitate product realisation processes, presently, research is actively being carried out to develop methodologies and technologies to support geographically dispersed teams to organise collaborative design based on the quickly evolving information technologies. A number of research works and commercial systems have appeared to provide solutions for collaborative and distributed product development, and the practical applications are getting more pervasive and mature. In this paper, the recently related works are summarised from three aspects—visualisation-based collaborative systems, co-design collaborative systems and CE (concurrent engineering)-based collaborative systems. Around these aspects, about 100 papers and 30 commercial systems/international standards published or launched recently are discussed. The current research and development statuses and issues, underlying algorithms, mechanisms and system architectures, and the future trends and challenges are explained and compared in detail.     

并行工程中的产品开发过程规划方法研究

从产品开发各过程单元之间的依赖关节出发,详细研究了识别产品开发中的耦合过程集合的有效方法。提出了以耦合过程集合识别为基础的产品开发过程规划策略,为并行工程的实施提供了基础。     

Requirements management: an enabler for concurrent engineering in the automotive industry

Defining and agreeing the product requirements is especially important when the design and manufacture of a system is part of an Extended Enterprise. To realize an all-inclusive concurrent engineering process, tools for the upstream design activities are needed. In practice, it is often difficult for the companies to have a shared understanding of what needs to be developed, and so specifications contain ambiguities in describing the product requirements. This paper clarifies the problem domain in the context of a complex product, designed and manufactured in a pan-national Extended Enterprise and serving a highly competitive market. The authors show how the challenge can be addressed through the application of ontology. A model of a requirements-management tool is proposed that will allow the various systems and associated levels of a product to be described and then shared through the supply chain. A prototype system is presented and illustrated through a case study from the automotive industry.     

A method for evaluating functional content in mechatronic systems using optimisation

This paper presents a method to support designers and product planners in determining the functionalities that should be implemented in a product and those that should not. The proposed method identifies the set of customer functions and technical implementations that maximise the potential product profit. The customer functions represent the functionality of the product, and the technical implementations are the hardware and software components needed to realise these functions. For industrial applications, the numbers of possible combinations of customer functions and technical implementations are extremely large. We present a mathematical framework that handles this problem. Furthermore, optimisation is employed to find the set of customer functions that will maximise profit when subjected to a restricted development budget in order to find the best possible business case. The method was evaluated on an industrial case study of active safety systems performed at Volvo Cars. Based on this case study, the proposed method shows a substantial potential compared to the methods presently used.     

Cost management through product design: target costing approach

The purpose of this study is to explore the role of target costing in managing product costs while promoting quality specifications that will meet customer requirements. In addition, it aims to develop a target costing module that will simplify implementation of target costing especially in small and medium enterprises (SMEs). Tools of operations management such as quality function deployment (QFD) and value engineering (VE) have been considered and evaluated in terms of their integration into the target costing. In order to investigate the total effect, an implementation of the QFD deployment–target costing process (QFD–TC process) was conducted in a small manufacturing company. Previous studies on target costing were mostly conducted in lead companies. This study focuses on implementation of the QFD–TC process in SMEs. Overall, it was found that the QFD–TC process was an essential technique in managing the costs of both a product and the overall production process. Combining target costing with QFD and VE techniques provides companies with a competitive cost advantage.     

Producibility Analysis Using Metrics Based on Physical Process Models

This paper presents an approach to evaluating producibility which is intended to enhance the ability of engineers to quickly design low-cost and high-quality parts. We divide all production processes into two categories: trajectory-dominated processes in which a generic tool is moved in a trajectory to form the part shape, and process-physics-dominated processes in which shaped tools are used to form similarly shaped parts. We focus on process-physics-dominated processes and on producibility problems that arise because of part shape. We argue that for these processes the currently popular approach of representing parts as collections of geometric features may be inappropriate for evaluating producibility. We propose an alternative approach and representation. Our approach consists of first identifying the different failure modes of the process and then defining producibility metrics corresponding to the likelihood of encountering each failure mode. This set of metrics is used to represent the degree to which a part is easily manufactured. Finally, we demonstrate this approach by developing a set of metrics for evaluating the producibility of aluminum extrusions. We use extrusions from the Boeing 777 to validate the metrics.