Modelling end of life phase of the complex products: the case of end of life aircraft

There are different approaches to modelling the products at the End of Life (EOL), including closed loop approach, the ladder of lansink and material flow. The sustainability principles and the complexity of the products may affect the choice of modelling type. The life cycle costs, several subsystems and the interaction between design features, construction, technology, suppliers and legislation affect the degree of complexity of the products. Hence, developing appropriate strategies are required for modelling EOL phase of the complex products. This article presents strategies for modelling EOL phase of complex products considering sustainability tools, EOL phase models and the characteristics of these products. An ingenerated approach is proposed to address the four essential aspects of the complex product at the EOL: operational, tactical, strategic and sustainability. The case of aircraft at the EOL is presented to highlight the application of the proposed approach.     

A holistic decision support tool for remanufacturing: end-of-life (EOL) strategy planning

Remanufacturing is a key enabler for sustainable production due to its effectiveness in closing the loop on material flows, extending product life cycle and reducing production waste and emission. In this paper, a holistic decision support tool to facilitate the product end-of-life (EOL) strategy planning, specifically using remanufacturing as a key strategy is presented. The proposed model incorporates checklist methods to evaluate the viability of conducting remanufacturing for a product and its components. An optimization model for determining the Pareto set of optimal EOL strategies that correspond to maximum economic profit and minimum environmental impact is presented. Since determination of this Pareto set via enumeration of all EOL strategies is prohibitively time-consuming, even for a product with a small number of components, genetic algorithm (GA), specifically NSGA-II has been utilized to achieve rapid calculation of the set of optimum EOL strategies. This NSGA-II method permits extensive sensitivity analysis to understand thoroughly the impact of situational variables, such as reverse logistic cost, technology and replacement part availability, etc., on the EOL decision making, i.e., Pareto front, and thus leading to improved strategy planning and better productdesign. The case study involving EOL treatment of two types of desktop phones is described to illustrate the utility of the proposed methodology.     

Product end-of-life options selection: grey relational analysis approach

Management of the product end-of-life (EOL) for a manufacturing enterprise is important. An improper EOL strategy can negatively affect the productivity and profitability and undermines the reputation of an enterprise because of the growing demands for extended producer responsibility. Producers need tools and methods to evaluate each EOL option since it is a complicated but must-be-accomplished task to achieve in order to solve the multiple-criteria problem that combines aspects such as eco-system quality, environmental impacts, human health issues, and economic factors etc. This paper presents an alternative decision-making process to generate an optimal solution from a list of EOL options under the uncertainty condition of incomplete information. Using Grey Relational Analysis, the multi-criteria weighted average is proposed to rank the product EOL options with respect to several criteria at the material level. It will guide the selection process and help a decision-maker solve the selection problem. The method is demonstrated with an example. Various EOL options are evaluated using the developed multicriteria methodology that takes account the environmental, economical and social factors.     

CONDENSE: A concurrent design evaluation system for product design

In dealing with the issue of integrating design and manufacturing, concurrent design evaluation plays an important role. This paper presents a concurrent design evaluation system (CONDENSE) developed to help product designers in evaluating possible design solutions and design alternatives during the early stage of design. It consists of two important functions: a qualitative aspect evaluation applied during the stage of searching for combinations of solution principles to help determine the design specifications, and a quantitative aspect evaluation applied to provide information on performance, assemblability, manufacturability and costs to facilitate design selection. The framework of CONDENSE is based on a blackboard architecture that requires the classification of knowledge into appropriate knowledge sources. As design data are interrelated and may have uncertainty, a graph decomposition algorithm is used in constructing the knowledge sources, and a linguistic evaluation module is integrated with the qualitative aspect evaluation subsystem to deal with data uncertainty. The proposed system has been validated with respect to the design of golf club heads. The results, which have been validated by experienced designers, are promising and can contribute to the speed-up of design and development, improvement of design quality and facilitation of design selection.     

心流理论下公共健身服务设施设计评估研究

目的 为提供不仅能加强用户黏性以形成激励循环,还能提高用户使用专注度的公共健身服务设施,提出将心流理论、AHP层次分析法和模糊综合评价法理论融合形成产品设计评估的研究方法。方法 首先,提炼心流理论各阶段下公共健身设施的设计需求,构建心流阶段设计要素评估指标体系;其次,利用AHP层次分析法进行定性分析和定量分析,经计算与检验得出具有客观性的综合权重排序,根据排序结果指导智慧划船机健身设施的设计实践;最后,运用模糊综合评价法进行设计评估验证,得到最佳设计方案,并进行改善。结果 经过研究与分析,设计了心流理论、AHP层次分析法和模糊综合评价法结合的产品设计评估理论方法,并以智慧划船机为例进行了理论研究方法的可行性验证。结论 多理论结合的产品设计方法,有助于进行公共健身服务设施的设计指导与方案评估,在使健身用户获得最优健身体验的同时,也为同类产品设计提供理论参考。     

Multicriteria decision-aid approach for product end-of-life alternative selection

The selection of the best compromise alternative for treating a product at its end of life (EOL) is presented. Each EOL alternative has its own consequences from an economical, environmental and social point of view. The criteria used to determine these consequences are often contradictory and not equally important. In the presence of multiple conflicting criteria, an optimal EOL alternative rarely exists. Hence, the decision-maker should seek the best compromise EOL alternative. The present paper proposes a multicriteria decision-aid (MCDA) approach to aid the decision-maker in selecting the best compromise EOL alternative on the basis of his/her preferences and the performances of EOL alternatives with respect to the relevant environmental, social and economic criteria. This approach is important because it allows the user to consider various conflicting criteria simultaneously and it takes into account his/her preferences. The paper analyses the most important aspects of this approach such as the constitution of a set of EOL alternatives, the selection of a list of relevant criteria to evaluate the EOL alternatives and the choice of an appropriate multicriteria decision-aid method. A case study is provided to illustrate how the proposed approach can be used for product EOL alternative selection in real-world applications.     

Eco-architecture analysis for end-of-life decision making

In order to improve ease of disassembly and recycling of a product at its retirement stage, it is essential to design a product architecture that allows for easy disassembly and recycling. In this paper, a novel concept of eco-architecture is introduced, and the eco-architecture analysis, a design approach supporting the end-of-life decision making process, is proposed. The eco-architecture is the product architecture described from the end-of-life (EOL) viewpoint, in which a product is represented as an assembly of end-of-life modules. Not only does it prescribe an EOL strategy, but it also gives information about the connections and arrangement among EOL modules. Therefore, understanding the eco-architecture is helpful in enhancing the disassembly and recycling capabilities of an architecture design. The proposed eco-architecture analysis supports architecture improvement; it helps designers to derive the most desirable eco-architecture which entails the optimal end-of-life strategy. It also facilitates the extraction of meaningful redesign guidelines which make it possible to improve an architecture in an efficient and effective manner.     

A bill of materials-based approach for end-of-life decision making in design for the environment

Re-use, recycling or remanufacturing of products and components are good alternatives for reducing the environmental problems resulting from the huge amounts of waste currently arriving at landfills. A new approach is proposed in this paper for enhancing these alternatives from the earliest stages of product design. Given the product structure (obtained from its bill of materials (BOM)) and the joining and geometrical relationships among the components (obtained from the three-dimensional, computer-aided design representation), a model is proposed that will determine the EOL (EOL) strategy, i.e. the depth of disassembly inside the structure and the final end (re-use, recycle, remanufacture or disposal) for each disassembled part leading to the highest profit. A scatter search (SS) metaheuristic is used to determine the disassembly cost at each level of the BOM. The model presents a number of major improvements with respect to previous research. It addresses the problems of simultaneously determining both the best EOL strategy and the disassembly sequence, as well as allowing removal of components not only over the two or three Cartesian axes and affording the possibility of modifying the encountered strategy in a further step so as to fulfil other business criteria (such as disassembly time, resources availability or maximum waste generation rate).     

A Framework for Reliability Prediction During Product Development Process Incorporating Engineering Judgments

This paper presents a comprehensive framework for reliability prediction during the product development process. Early in the product development process, there is typically little or no quantitative evidence to predict the reliability of the new concept except indirect or qualitative information. The proposed framework addresses the issue of utilizing qualitative information in the reliability analysis. The framework is based on the Bayesian approach. The fuzzy logic theory is used to enhance the capability of the Bayesian approach to deal with qualitative information. This paper proposes to extract the information from various design tools and design review records and incorporate it into the Bayesian framework through a fuzzy inference system. The Weibull distribution is considered as failure/survival time distribution with the assumption of a known value of shape factor. Initial parameters of the Weibull distribution are estimated from warranty data of prior systems to estimate the initial Bayesian parameter ( λ_t). The applicability of the framework is illustrated via an example.     

Sustainable disassembly line balancing model based on triple bottom line

End of life (EOL) phase of a product is receiving more attention due to increase in environmental concerns, and many studies have been conducted for value creation in EOL, focusing on concepts as remanufacturing, reuse and recycling in sustainable production manner. This study especially focuses on one of global problem, e-waste. To minimise the amount of wastes and maximise recovered materials from EOL, disassembly is one of the most important concept, associated with reuse, and balancing disassembly line in an optimal way is essential for organisations. In disassembly line balancing (DLB), not only precedence of tasks, but also risk criteria related to environment and human safety should be considered for sustainability. The aim of this study is to propose a model based on triple bottom line (TBL) dimensions, i.e. human safety, environmental safety and business criteria. To achieve sustainability in DLB, and for risk assessment in sustainable DLB, it had been decided to use a multi-criteria method, i.e. TODIM, acronym in Portuguese of ‘Tomada de Decisão Iterativa Multicritério’. The proposed model included 22 disassembly criteria categorised under TBL dimensions, which are derived from the literature. Implementation of the study was conducted for computer disassembly processes, and as a result of the study approximately 12% an improvement in cycle time was succeeded. In the long run, the integration of sustainability in disassembly operations may contribute to the competitive advantage of the company in terms of differentiation and corporate image by achieving business, environment and human targets simultaneously.     

Process Uncertainty: A New Dimension for New Product Development

Abstract

Companies pursuing product leadership continually push products into innovative technology areas and new unknown markets. As companies continue to strive for continuous innovation, often leapfrogging even their own technology, new product development (NPD) processes play an increasingly important role in defining the success or failure of many new innovations. In addition, increased competitive rivalry is driving companies to commercialize their new products much more quickly. To meet these pressures, new strategies are being used to supplement the conventional new product development process that consists of strategy formulation, idea generation, screening and evaluation, development, testing, and launch. The primary objective of each of these innovation strategies is to attain sustainable competitive advantage for the company and achieve higher overall performance.

Our research examined product and service innovation strategies of six projects. Half of which were considered successful and the other half failures. Using several emerging innovation strategies including process-driven, speed-to-market, quantitative, market-driven, technology-driven, and learning-driven to classify these projects, we evaluated the innovation strategies employed in an attempt to determine the overall NPD strategy effectiveness. In addition, we also attempted to identify relevant critical success factors and associated activities to construct an ideal innovation strategy model.

In the projects we studied, we found that no one best strategy leads to successful innovation. While evaluating areas of uncertainty that impact project success, we determined that a new dimension, process uncertainty, plays as important a role as market or technical uncertainty previously examined in the emerging scholarship. Furthermore, the insights that were discovered by comparing the different innovation strategies led us to formulate the technical-market-process (TMP) uncertainty mode. The TMP model serves as a predicator for identifying the appropriate innovation strategies that can be brought together to drive project success. We conclude that the combination of identifying the appropriate innovation strategies and proficiently executing these strategies is the key to successful new product development.     

A Failure Mode Effect and Criticality Analysis of Conventional Milling Machine Using Fuzzy Logic: Case Study of RCM

The purpose of this paper is to select the appropriate maintenance strategies for each failure mode of functionally significant item of conventional milling machine. In order to describe the criticality analysis of conventional milling machine, this paper presents a study on reliability‐centered maintenance with fuzzy logic and its comparison with conventional method. On the basis of fuzzy logic, failure mode and effect analysis is introduced integrating with fuzzy linguistic scale method. After that, weighted Euclidean distance formula and centroid defuzzification is used for calculating risk priority number. The results indicate that based on risk priority number, value criticality ranking was decided, and appropriate maintenance strategies were suggested for each failure mode. It also reflects that a more accurate ranking can be performed by the application of fuzzy logic using linguistic rule to failure mode and effect analysis. Copyright © 2016 John Wiley & Sons, Ltd.     

Improving product based on affordance with fuzzy theory for product development strategy

This paper presents a design strategy which combines both conceptual and mental design information to quantitative degrees of affordance using a fuzzy scale that provides user-to-designer information. The traditional communication channel has been hidden. In the past, design concepts were not a result of direct communication between designers and users. This study found that, based on users’ mental models, users can reflectively modify product characteristics to improve the convenience of usage. These insights offer a hidden communication channel for designers and are defined as generalised affordance within the context of this research. This study proposed a novel method to semi-quantify affordance using a fuzzy linguistic modelling technique to establish a fuzzy scale table that quantifies degrees of affordance. An affordance fuzzy matrix (AFM) was created to assess the effects of affordance of each task necessary to utilise each product component. The overall results of the AFM indicate the generalised affordance of a particular product. Hidden messages are the characteristic of a product improved by the user itself because of his habit, which incurs additional product features, symbols and words, and will help product designers for further design strategy and improvements. In this study, generalised affordance is applied to an electric oven as an example.     

基于AHP和模糊综合评价方法的儿童早教机设计

目的针对产品进行创新设计及方案选定,提高产品设计过程中的合理性和科学性。方法运用AHP(层次分析法)与模糊综合评价法,形成儿童早教机的综合性评价。首先,通过层次分析法进行层次划分,构建指标评价体系;其次,建立判断矩阵计算各要素权重值,对结果进行一致性检验并排序;最后,结合模糊综合评价法对三种设计方案进行决策,解决多方案优化排序问题。结论通过运用层次分析法与模糊综合评价法,有效地为设计方案提供客观的决策依据,并对其他同类别产品设计研究提供一定的参考价值。     

复合材料成型工艺方法的模糊综合评判

针对目前纯数学推理方法和IF-THEN的知识表述方法在复合材料成型工艺方法的确定中存在单一和不可靠的缺点,通过对复合材料制件特征、成型方法、制造资源的分析,以制件的可制造性、生产成本、生产周期为基础,采用分层法构造了一个基于模糊数学的树形分级多目标评估体系模型.采用1~9比率法给出了该模型下具体指标的隶属度,讨论了权重分配问题,并通过实例分析验证了该方法的可行性,实现了复合材料成型方法的优化.     

基于模糊层次分析法的金箔文创产品设计研究

目的 为保障金箔文创产品开发中文化元素的准确筛选及创意方案的客观评价,提出一种基于模糊层次分析法的金箔文创产品设计方法,并通过设计实践进行分析验证,为金箔文创产品的开发提供模式参考和策略建议。方法 首先,通过焦点小组法按设计前后阶段划分两组评价指标,运用层次分析法创建一套综合评价体系并确立各指标权重;其次,采用KJ法归纳文化元素并用模糊综合评价进行排列筛选;再次,采用案例借鉴和因子提取法围绕文化元素进行创意设计;最后,合并所有子指标再次使用模糊综合评价对所有设计方案进行评价和优选。结果 设计人员通过模糊层次分析法的运用,筛选出金陵十二钗和南京特色美食两组文化元素,分别设计出金箔书签和金箔钥匙扣两套金箔文创产品方案,并通过了可行性评价验证。结论 通过运用模糊层次分析法,初步构建了适合金箔文创产品的开发模式,在文化元素筛选阶段,可以帮助设计师准确排序并确立文化元素,把握文创产品的核心内涵;在创意设计阶段,能为设计提供一定决策建议,并为设计方案评价和优选提供保障,使设计过程更加理性和高效。     

A multi-objective fuzzy graph approach for modular formulation considering end-of-life issues

Increased awareness of the negative environmental impact caused by electronic waste has driven electronics manufacturers to re-engineer their product design process and include product end-of-life considerations into their design criteria. Design for the Environment (DfE), as a possible solution, lacks an implementation framework. To address this problem, a fuzzy graph based modular product design methodology is developed to implement DfE strategies in product modular formulation considering multiple product life cycle objectives guided by DfE. A fuzzy connected graph approach is used to present the product structure, whereby fuzzy relationship values are determined by applying Analytic Hierarchy Process (AHP) to life cycle environmental objectives along with other functional and production concerns. Based on the fuzzy connected graph, an optimal modular formulation is searched using the graph-based clustering algorithm to identify the best module configuration. An example is provided to illustrate the methodology and the algorithm presented in this paper.     

家具产品用户体验的模糊综合评价研究

目的研究基于用户体验的模糊综合评价法来指导家具设计。方法以新中式客厅组合家具为例,从用户体验的角度建立基于感官、交互、品牌、技术的多层次多指标设计评价模型,进而确定各指标权重值,应用模糊综合评价方法对设计进行评价。结果通过比对设计方案和改进方案的评价结果,验证了该方法对家具设计的指导作用。结论应用此方法可对产品设计进行综合量化的评价,可对设计改进和方案优选提供有效帮助。     

Design and realisation of an efficient environmental assessment method for 3R systems: a case study on engine remanufacturing

Recently, the manufacturing industry has been striving for sustainability because of the environmental degradation and resource depletion caused by it. Remanufacturing considerably saves material and is energy efficient, and thus, it can represent an important solution to environmental issues. However, the uncertainty of remanufacturing makes the practical management of closed-loop supply chains (CLSCs) difficult. To unlock the value potential of end-of-life (EOL) products, we studied a reuse, remanufacture, and recycle (3R) processing system under quality uncertainty for returned EOL engines. In the system, the returned cores were distributed into different processing routes, depending on the results of quality grading. The proposed matrix operations could efficiently assess the environmental benefits; moreover, we designed an algorithm to calculate the quality coefficient that reflects the overall quality condition of returned EOL cores. The impacts of quality uncertainty on the environment could be efficiently quantified via our proposed method. Furthermore, using Monte Carlo simulation and the law of large numbers, we devised a model to establish direct and definite quantitative relationships between the quality coefficient and production indexes. This model provides a basis for the formulation of optimal acquisition strategies under different returning scenarios.     

A framework for designing robust supply chains considering product development issues

The primary objective of the design for supply chain (DFSC) is the selection of an appropriate product family. Moreover, it deals with the selection of the optimal combination among the different conflicting criteria while making a trade-off between the supply chain cost, sales profit and the product design complexities. In this research, to address the DFSC issues a product platform approach has been proposed which amalgamates the component modularity as well as the function modularity in the product design. The optimisation model proposed in this paper for the product development and the supply chain design is based on a generic bill of materials (GBOM) representation. The complete framework includes vital decision-making needed for designing a robust supply chain such as locating plants to alleviate the likely dominance of production cost and market mediation cost on product variety and imparting process flexibility of the located plants. The optimisation model proposed in this paper, models the supply chain cost, sales profit and product design complexity as three criteria that altogether determine the robustness of the supply chain and the underlying product development approach. Certain parameters like process flexibility, flow types and drivers of the product variety dominance have been controlled in the design framework. To resolve the complexity of the proposed model a genetic algorithm (GA) technique has been proposed. The proposed GA adopts an arithmetic crossover, a dynamic mutation and a variable penalty strategy to produce optimal results in a very short computational time. To validate the proposed model, a simulated case study of the wiring harness supplier of an AGV manufacturer has been studied.