To establish a circular manufacturing system, continuous management of the resource flow and the condition of individual items including products, components, and the materials in the system is indispensable. This study proposes a life cycle simulation (LCS) based management method to support optimal decision-making under conditions that include various uncertainties, such as consumer behavior and market trends. LCS is a simulation method that simulates dynamic material flow in the entire life cycle system and enables the evaluation of environmental and economic efficiencies. Since the simulation model consists of many parameters, exhaustive simulations with all parameter combinations are impossible in a practical timeframe. Therefore, the method extracts parameters that have a significant impact on eco-efficiency through sensitivity analysis using LCS. Then, a response surface of multi-level resolution is created in a multidimensional space composed of the parameters. The response surface is used to quickly identify optimal parameter values under uncertain conditions for effective management. As a case study, the proposed method is applied to the management of a circular manufacturing system for lithium-ion batteries of automotive to verify the effectiveness of the management on eco-efficiency.

Car- and ride-sharing services being increasingly used around the world have the potential to promote the diffusion of electric vehicles. Therefore, it is important to estimate environmental load changes resulting from the diffusions of car- and ride-sharing services and electric vehicles throughout vehicle life cycles. In this study, we propose a life cycle simulation (LCS) method that focuses on the diffusions of sharing services and electric vehicles. Car- and ride-sharing services diffusion influences the travel demand and changes the total number of manufactured vehicles. On the other hand, the diffusion of electric vehicles depends on policies of a targeted area and increases the number of manufactured electric vehicles. The proposal LCS method includes two-stage allocation mechanism to integrate the effects of these two types of diffusion. The results of a case study show that this method is able to handle the integrated effects of these two diffusions.

© 2020 The Author(s) A number of thematic scenarios have been developed for envisioning sustainable futures in order to support strategic decision-making for government and industry. However, methodologies for designing scenarios have generally been under-theorized. For a better understanding and communication among stakeholders involved, this paper aims to propose the concept of computer-aided scenario design whose key characteristic is to provide a graphical representation of scenarios. That is, the paper proposes a method for representing the logical structure of a scenario by drawing the idea of graph theory. Based on this representation method, the paper dynamically connects a scenario with its associated simulators for undertaking what-if analysis in a quantitative manner. In an illustrative case study, the proposed method is applied to an extant scenario for hybrid electric vehicle diffusion. The results show that the method clarified the logical structure of the scenario and the rationales for deriving the scenario's conclusions. It was also demonstrated that the method enabled to create scenario variants when the original assumptions were changed. The proposed method would facilitate the iterative process of scenario design, thereby encouraging scientific dialog between researchers and stakeholders.

自動車シェアリングは環境負荷を減少させる手段として注目されている．これまでの自動車シェアリングを考慮したライフサイクル評価では，環境負荷は使用段階の走行距離に大きく依存することが示されている．しかし，シェアリング車使用時の挙動変化の詳細なモデル化は困難である．本稿では，エージェントベースドモデルとライフサイクルモデルをハイブリッド化し，自動車挙動を考慮したライドシェアリングの環境負荷を評価する．

途上国で生まれたイノベーションが先進国で展開されることをリバースイノベーションという．本稿では，途上国の既存製品をもとにした先進国での新製品設計手法を提案する．途上国特有の状況に基づいて先進国のユーザーセグメントを設定し，先進国特有の要求を加味して再設計を行う．ケーススタディとして，ベトナムのてこクランク機構を用いた三輪車いすを日本の特定ユーザー向けに再設計した．

© 2020 The Author(s). Published by Elsevier B.V. Decreasing total natural resource input is critical for sustainability. Thus, improving resource efficiency is increasingly required at all levels from products to industry-wide systems. Product lifecycle systems and business models for circular economy, such as remanufacturing and sharing products, have been developed in only particular markets. Lifecycle processes of different products are often connected after sales, even if the products and their lifecycle processes were developed by independent companies or business communities. This study focuses on one such complex system called “connected lifecycle systems,” which is a system of systems comprising product lifecycle systems. Connected lifecycle systems can be regarded as industrial symbiosis in wide areas. The objective of this paper is to propose a hybrid simulation architecture for more realistically calculating dynamic material flow in connected lifecycle systems.

© 2020, Fuji Technology Press. All rights reserved. Systematic lifecycle design and management are promising approaches for constructing sustainable product lifecycle systems. Lifecycle simulation (LCS) has been used to evaluate a product lifecycle in the design phase from both the environmental and economic perspectives. Based on material flows through each process of the product lifecycle, the LCS calculates the time variation in environmental loads, cost, and profit. In each process of the LCS model, functions that regulate the behaviors of the process, called behavior functions, are set, and these functions control material flows. Previously, we proposed a data-assimilated LCS method that combines data assimilation (DA) with LCS to realize adaptive management based on actual states of the product lifecycle. In this previous development, the DA mechanism modified the material flows of an entire lifecycle in the simulation model based on actual flows observed in each process at the time of the DA. However, because process behaviors were not modified, the gap between material flows predicted by the simulation and the flows of the actual lifecycle increased over time. To overcome this limitation, in this study, we propose a new DA mechanism that modifies the behaviors of un-observed processes based on observed material flows. The proposed DA mechanism uses the response surface methodology to estimate the behaviors while tracing the causal relation in the LCS model in reverse. A case study on a photovoltaic panel reuse business showed that the DA mechanism successfully merged the observed data into the process behaviors in the LCS model including the processes where no data were observed, thereby improving the accuracy of the simulation for future pre-diction. Systematically analyzing the current and future process states of the product lifecycle can support decision-making in lifecycle management.

自動運転車は機能レベルに基づいて分類されており、部分自動運転、高度自動運転、完全自動運転と段階的な市場化が見込まれる。自動運転車の機能レベルの変化はセンサ類の構成、燃費、事故率など車の製造、使用、廃棄プロセスに影響を及ぼすと考えられる。本研究では、個人所有車における各機能レベルの自動運転車の普及シナリオを基に、車のライフサイクル全体での自動運転車の環境負荷評価を行った。

© 2019, Springer Nature Singapore Pte Ltd. This paper focuses on the fulfillment of fundamental human needs in the achievement of sustainable consumption and production (SCP). Here, we focus on the Human-scale development (HSD) theory proposed by Chilean economist Max-Neef, in which the following nine fundamental needs are introduced: subsistence, protection, affection, understanding, participation, idleness, creation, identity, and freedom. In HSD, an important role is played by satisfiers, which are ways of fulfilling the above-mentioned fundamental needs in a particular context, such as climate and culture. From the standpoint of a producer, satisfiers are regarded as the starting points of product development for SCP. This paper introduces the opposite concept, referred to as a barrier—a factor that interferes with fulfilling fundamental needs. The purpose of this paper is to determine the satisfiers and barriers for younger people in Vietnam based on the results of needs-based workshops. Around 1200 satisfiers and barriers were extracted; however, barriers were largely equivalent to satisfiers. We found that the concept of satisfiers is useful to achieve SCP, because it is comprehensive, realistic, and provides an opportunity for social practice.

© 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license Car- and ride-sharing services are focused on environmental and new business issues in recent years. This study analyzes environmental effects of the transition from car ownership to sharing services and aims to clarify sensitive parameters by sensitivity analysis. The following steps are carried out: 1) model causal relationships between variables in ownership and sharing service business models, 2) develop life cycle simulation models of gasoline and electric vehicles based on these causal relationships, and 3) analyze transition scenarios. The results show that carbon dioxide emissions and copper usage decrease with the diffusion of car- and ride-sharing services, and that the average number of vehicle passengers is the most sensitive parameter for car- and ride-sharing services.

© 2018, Fuji Technology Press. All rights reserved. Reuse is an effective method of circulating resources in terms of environmental benefits because it requires fewer resources and less energy than manufacturing new products from virgin materials. In global reuse, a used component or module is reused in a different application. To evaluate a system of multiple product lifecycle systems (PLSs), the lifecycle simulation methodology LCS4SoS has been proposed. LCS4SoS comprises three elements, namely, individual PLSs, interactions among them, and their evolution over time. This paper proposes a lifecycle simulation method for global reuse based on the LCS4SoS framework. Flow control rules are developed for global reuse to control the directions and quantities of material flow among the PLSs. The usefulness of this method is verified by a case study of automobile and stationary battery PLSs.

© 2018, The Author(s). Achieving a sustainable consumption and production pattern is one of the United Nation’s sustainable development goals for 2030. To achieve this, it is necessary to consider the environmental burden from a product life cycle and the quality of life of the consumer. In this study, a systematic approach for connecting basic human needs and the product development process, called the living-sphere approach, is proposed. This approach is intended to encompass the complete relationship between region-specific basic needs and durable products. In this approach, value graphs, which visualize the value system of products, are connected to satisfiers fulfilling the basic needs set out by Max-Neef. A value graph links satisfiers and the traditional product development process. The significance of the proposed approach is twofold. First, improving quality of daily life and traditional product development are combined in the same framework. Second, the design of single products and the total optimization of multi-products are supported at the requirement level.

© 2018 Elsevier Ltd To realize environmental sustainability, the flow of natural resources into industrial systems must be reduced and stabilized at a suitable level. One way to reduce resource flows in society is to establish resource-circulating manufacturing systems. To foster the circulation of resources in industry, life cycle simulation (LCS) technologies, which are based on discrete-event modeling, have been developed to dynamically evaluate the life cycles of products from resource extraction to end of life from both environmental and economic aspects. In reality, various industrial products interact with each other in unanticipated ways, and then these interactions affect the material flows in product life cycles. This type of complex system is called a system of systems (SoS). Focusing on this issue, we expand the evaluation's system boundary to include a system of multiple product life cycle systems. To handle an SoS quantitatively, we introduce typical types of interactions between product life cycle systems. The purpose of this study was to propose a new LCS methodology, called “LCS4SoS,” that focuses on an SoS consisting of different kinds of product life cycle systems. A prototype system of LCS4SoS was implemented based on this proposed methodology. Through a case study, it was found that the proposed methodology is useful for evaluating an SoS consisting of multi-product life cycle systems.

カーシェアリングが世界中で展開されており、環境的・経済的観点からも注目されている。特に、自動車走行距離、自動車保有台数、CO₂の削減に効果があると言われているが、これらは車の製造や使用といったプロセスのみに注目しており、ライフサイクル全体での環境負荷の評価が課題となっている。本研究では、製造、使用、廃棄を含む、自動車のライフサイクル全体でのカーシェアリングの環境負荷の評価を行った。

© 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. Reducing environmental loads and resource consumption throughout the product lifecycle is one approach to address environmental problems. Lifecycle simulation (LCS) is a tool to evaluate environmental impacts considering lifecycle options such as maintenance, reuse, and recycling. Various interactions exist between different product lifecycle systems. For example, to increase the energy density and cycle life, a lithium ion battery (LiB) from an electric vehicle (EV) can be reused in a stationary battery (SB). Considering these interactions, a new LCS method that includes multiple product lifecycle systems is needed. In this research, which assumes that a system of systems (SoS) consists of different product lifecycle systems and their interactions, flow control rules among different product lifecycle systems are developed and applied as a case study to LiB reuse in SB from EV.

© 2018 The Authors. Published by Elsevier B.V. Durable equipment requires regular maintenance throughout the lifecycle to achieve the expected performance and reliability under acceptable maintenance costs. This paper proposes a maintenance scenario evaluation method for point-of-sale (POS) terminals. The scenarios are the description of differences in the intervals and contents of maintenance service, which diversify the frequency of product failures and the maintenance costs. The evaluation method quantifies risks caused by the failures based on lifecycle simulation (LCS) and risk assessment to support selecting an appropriate maintenance scenario. In the method, the LCS calculates the frequency of failures and the monetary flow of maintenance activities, and the risk assessment is used to estimate the degree of risks depending on the maintenance scenario.

We report, from the perspective of participants, about the project-based learning class where engineering and non-engineering students collaboratively tackled manufacturing. It aimed to cultivate the design thinking ability of master course students coming from various departments of Osaka University. Although we had less backgrounds of engineering or manufacturing, we succeeded in defining user needs and creating a product which meets them. We subsequently participated in an international conference on engineering design and presented another product there. Since design thinking could be applied there as well, we could win the championship. Manufacturing is a good way for students to experience problem solving, so we could gain more than simple knowledge of engineering.

<p>This paper proposes an interactive image-based re-modeling system for virtual reshaping of real objects via a video see-through display. The system provides a quasi-realistic design environment in which a designer manipulates the shape and location of real products installed in a real living space. A prototype of the proposed system is developed by integrating two sub-systems for solid modeling based on 3D-CAD and visualization based on image-based rendering. A case study of the virtual redesign of real products illustrates that the proposed system allows designers to examine various design changes on the existing products in an immersive and realistic 3D environment.</p>

© 2017 The Authors. One of the practical approaches to environmental issues in developing countries is introducing eco-products made in developed countries. However, such products are not always acceptable due to differences of various contexts in the different regions. It is necessary to understand how such local conditions are related with product function and structure. The aim of this study is to develop a design support system for visualizing design information for locally-oriented product design. The system aids users in understanding relationship among product specifications and local information. The authors show a case study on home electric appliances in Vietnam and Japan to validate the system.

© 2017 This paper proposes a data-assimilated lifecycle simulation (DA-LCS) system. Data assimilation (DA) is a self-adjustment method for decreasing differences between a simulation and observation data from an actual-system by conforming the simulation model parameters to the observation at appropriate time intervals. The proposed system applies DA to LCS for adaptive operations in product lifecycle management. A case study of the lifecycle of a photovoltaic panel reuse business shows that DA-LCS successfully merges measurement data acquired from actual business operations into the LCS model, and sequentially revises the simulation estimations through DA.

© 2017 The Authors. Life cycle simulation (LCS) evaluates dynamic material flows in the life cycles of a single product family. However, in reality, there are various interactions between different product life cycles, such as demand substitution among different types of products and the global reuse of components in other products. In this paper, an entire system consisting of multi-kind product life cycles is regarded as a system of systems (SoS), which is an assemblage of systems where each system possesses operational and managerial independence. This paper proposes an LCS system for SoS that will support engineers in making decisions about system management through describing and simulating interactions.

© Springer International Publishing AG 2017. Achieving a sustainable consumption and production pattern is one of the United Nation’s sustainable development goals for 2030. To achieve this, it is necessary to consider the environmental burden from a product life cycle and the quality of life of the consumer. In this study, a systematic approach for connecting basic human needs and the product development process, called the living-sphere approach, is proposed. In this approach, value graphs, which visualize the value system of products, are connected to satisfiers fulfilling the basic needs set out by Max-Neef. A value graph links satisfiers and the traditional product development process. The significance of the proposed approach is that improving quality of daily life and traditional product development are combined in the same framework.

<p>To utilize resources efficiently, realizing closed-loop manufacturing becomes a crucial issue. This paper proposes a design support method for a product life cycle in order to circulate resources efficiently by means of recycling, reuse, remanufacturing, and so forth. Our previous work has proposed a design object model, which represents a product life cycle from the viewpoint of both its nominal information and entity information. This study refers to a specific state of an individual product as 'entity information,' as opposed to 'nominal information,' which represents design information specified by designers. The method proposed in this paper extracts design parameters to be modified from the nominal information to achieve a design requirement by analyzing relationship of the parameters of the product and its life cycle flow described in the design object model. The method conducts sensitivity analysis on the extracted design parameters in order to identify a design parameter effective to achieve the design requirement. A case study on a product life cycle of a smart phone is illustrated for demonstrating the feasibility of the proposed method.</p>

Individual products have a variety of states depending on their life cycle histories even if they are produced from the same design information, which represents their nominal information specified by designers. We call a specific state of an individual product as &ldquo;entity information,&rdquo; as opposed to the nominal information. To utilize resources of products efficiently throughout the entire life cycle, this paper proposes a method for modeling both nominal information of a product life cycle and the entity information at its design stage. This method represents the nominal information with hierarchical product structure model and life cycle flow model, which we have already proposed in our previous study. In this paper, we propose a model of the entity information, which we call &ldquo;Entity Information Model.&rdquo; Entity Information Model represents states of individual entities and the changes of the number of the entities in each life cycle process such as maintenance, collection, and end-of-life processes by recording life cycle histories of individual entities. Entity Information Model is created by using life cycle simulation technique. A case study of a smart phone is illustrated for demonstrating the feasibility of the proposed method.

Fuel cell cogeneration is one of promising energy-saving technologies in pursuit of a sustainable society. However, it is unpredictable how many fuel cell cogeneration systems will be diffused since there are many future uncertainties, such as people's lifestyles and national energy policies. As an approach to tackling with this problem, this paper proposes a method for describing scenarios to analyze the diffusion of residential energy systems, such as fuel cell cogeneration systems. We develop a simulation model for estimating the diffusion of residential energy systems, in which conjoint analysis is undertaken to analyze consumers' preferences. In a case study, several scenarios are described for analyzing the diffusion of solid oxide fuel cell (SOFC) cogeneration systems for apartment houses, where the region of interest is Kansai Area, Japan from 2013-2030. The described scenarios differ in terms of nuclear energy policies. The results show that the number of fuel cell cogeneration systems in 2030 reaches 147-157 thousands depending on the share of nuclear power. In addition, it is revealed that monthly utility cost has a much larger impact on SOFC diffusion than CO₂ emissions. Future work includes further what-if analyses of the scenarios to identify factors that would give a significant influence on SOFC diffusion.

Manufacturing industry is required to transform itself into sustainable form. For this task, drawing images of sustainable manufacturing through developing a "scenario" is a hopeful means. When developing a scenario, the developers draw several future visions and transition paths qualitatively and quantitatively. However, scenario development is difficult and exhaustive task. In order to tackle this problem, referring the ideas of design engineering, we propose a framework of "scenario design" and develop a computational support method for scenario design. Based on this, we proposed a computable scenario model and a scenario design process. The proposed model includes sub models expressing intermediate states between the motivation for developing scenario and a documented scenario. We proposed a scenario design process includes four steps in which the scenario is designed in stepwise manner. In the first step, the designers clarify the objective, backgrounds, and outline of the scenario as a whole. In the second step, the designers determine the scenario structure, the number and outlines of sub scenarios. In the third step, the designers elaborate the details of the scenario qualitatively and quantitatively. At last in the fourth step, the result of the scenario design is documented for outreach activities. We implemented a backcasting scenario design support method proposed in a previous study on the design model and the design process. We developed a backcasting scenario design support system. As a case study, we designed Sustainable Manufacturing Scenario with the proposed method and the support system, in which economically and environmentally sustainable futures of Japanese manufacturing industry is envisioned. Through the case study, the effectiveness of the proposed design method and the support system is verified.

© 2015 CIRP. This paper proposes a computer-aided design method for semi-destructive disassembly with split lines. This method aims at extracting reusable, recyclable, or hazardous components more efficiently than manual disassembly with higher quality than shredding. The split line is a shape feature of a product that enables to destruct the product into desired shape, like pull tabs of cans. The proposed method aids a designer in adding proper split lines to extract target components. A case study showed that the semi-destructive disassembly sequence of an air conditioner with the split lines reduces the number of steps needed for extracting a target component.

© 2015 The Authors. Published by Elsevier B.V. Minimizing environmental loads and resource consumption is a major issue in the manufacturing industry while enhancing value of products. Individual products have a variety of states depending on their life cycle histories even if they are produced from the same design information. While design information represents their 'nominal information' specified by designers, we call a specific state of an individual product as 'entity information.' The differences in individual products make it instable in terms of the states and quantity to circulate resources and to deliver service activities at the after sales market. To realize efficient resource circulation and high quality services, designers should determine nominal information of a product and of its life cycle flow by analyzing the entity information at its design stage. This paper proposes a method for modeling both nominal information of a product life cycle and the entity information. This method represents the nominal information with product model and life cycle flow model. In this paper, we define a model of the entity information, which shows states of individual products and the number of the products in each life cycle process such as maintenance, collection, and end-of-life treatments. To create this model, we derive entity information throughout the entire life cycle flow by using life cycle simulation technique. A case study of a smart phone is illustrated for demonstrating the feasibility of the proposed modeling method.

© 2015 The Authors. Published by Elsevier B.V. Combination of long product lifetime and recycling is effective for reducing material use. However, in the case of products that uses energy in their use phase, early replacement of old products with new energy efficient products may contribute to reduction of lifecycle CO2 emission. In the previous studies, we proposed a formula to calculate optimum circulation period (OCP) of the products based on the improvement of energy efficiency. The formula was applied to the products produced in 1991-2000. This paper calculates the OCP of the latest products and analyzes the effect of rapid circulation of products. As a result, OCP and RCP effects are different from the previous studies, because characteristics of latest products are different from products of 1991-2000. Especially, OCP of Hybrid Electric Vehicles excesses three times than the normal product life span. Special case of rapid circulation between different type products, such as Gasoline Vehicles and Hybrid Electric Vehicles was effective for CO2 emission reduction.

© 2009 Fuji Technology Press Co,. Ltd. All Rights Reserved. In order to adapt to or overcome the difficulties Japan’s manufacturing industry is facing today, drawing normative future visions of sustainable manufacturing is required. The future is undeterminable, so the future visions cannot be fixed. Therefore, in order to draw visions of sustainable manufacturing of Japan, our research group has developed its Sustainable Manufacturing Scenario using the backcasting method. Here, a scenario is a set of stories detailing several future visions and transition paths toward them. Backcasting is a method of developing a scenario, one in which ideal future visions are developed, and then transition paths from the visions back to the present are drawn. To quantify and evaluate the future visions, we propose a model called SISA (Scenario-based Industrial Structure Analysis), which is based on Input-Output (I-O) tables. An I-O table quantitatively represents final consumption and transactions among industrial branches of a specific region in a specific period. In the SISA model, the I-O table representing future industry is given from the present I-O table, and several parameters reflect the hypotheses set in the scenario. Our research group has developed five different future visions of Japanese manufacturing industries. We set three future targets: GDP, employment, and CO2 . The visions are quantified on the SISA model and investigated as to whether they achieve the future targets or not. Based on this analysis, we have concluded that drastic technological change is required to achieve the CO2 target, and cooperation with service manufacturing is important if the employment target is to be met.

This paper proposes a design method for dismantling a product by adding split-lines to the product. This method aims at extracting target components for their reuse, recycling, and proper disposal. The split-lines enable to destruct a product into desired shapes, like pull tabs of cans and caps of PET bottles. The proposed design method supports a designer in determining split-lines to extract a target component. This method classifies the components of the product into shells that surround the target component and finds out the areas in which split-lines can be added for each shell. Then the method finds out candidates of dismantling sequences with split-lines from the candidates of each shell's split-lines. A case study shows that the dismantling of a LCD TV with split-lines reduces the number of manual operations needed for extracting a target component.

Recent years, various new energy products, such as photovoltaic (PV) systems and electric vehicles (EVs), have been diffused. While the diffusion of such products will affect the electricity demand of power grids, it is difficult to predict to what extent those products will be diffused in our society because the diffusion of such products depends on various unforeseeable factors such as energy policies. To analyze the influence of the diffusion of such products upon electricity demand, this paper describes several scenarios of future regional power grids. We focus on residential and commercial sectors because the end-use energy consumption in these sectors is, at least in Japan, increasing and it thus needs to be reduced. In the case study, we described scenarios in Toyonaka City, Osaka Prefecture, Japan. The results revealed that the total electricity demand in the residential and commercial sectors decreases 10.5% from 2012 to 2030 with population decrease. The diffusion of PV decreases the total electrical load of the grid by 19.7%. Moreover, EV diffusion has the potential to reduce the peak of electrical load by 37.3% by using batteries of EVs. © 2014 Published by Elsevier B.V.

A fuel cell is a promising element for saving energy by utilizing waste heat for hot water supply. When assessing the influences of fuel cells in a real world, however, the question is how many fuel cells will be diffused in a region because there are many unpredictable factors, such as national energy policies and consumers' lifestyles. This paper takes a scenario approach to analyzing the environmental impact caused by the diffusion of fuel cells under different social situations. A case study describes three scenarios for estimating the diffusion of solid oxide fuel cells (SOFC) for apartment buildings in 2030, in which conjoint analysis is undertaken for quantifying consumers' preferences. © 2014 Elsevier B.V.

Life cycle design is a promising approach for introducing efficient resource circulation. In such design, there are difficulties in balancing demand and supply for resources throughout product life cycles. For the resource balance, it is important to design a product life cycle focusing on individual products and their parts, since they change their states diversely and flow along different circulation paths through their life cycles. This paper proposes a modelling method for the individual products and parts in addition to its design information. The design information is the nominal information of the product specified by designers. To achieve this, this paper defines three models; hierarchical structure model, life cycle flow model, and entity information model. Hierarchical structure model represents design information of a product. Life cycle flow model represents a network of processes included in product life cycles. Entity information model represents information of individual products and parts. The information indicates when each product and part flows along which circulation paths in which state. With this information, this method represents resource balance throughout product life cycles. Moreover, this study employs life cycle simulation technique to derive the entity information model from the hierarchical structure model and life cycle flow model. We demonstrate the proposed modelling method via its application to a smart phone in a case study. © 2014 Published by Elsevier B.V.

Sustainable business is characterized by its facets to balance triple bottom lines (i.e., profit, planet, and people). In sustainable business design, it is crucial to consider interaction between the core business and external environment, which does not seem to influence the profit of the core business but necessary to explain their intended environmental and social value proposition. To construct a particular model of sustainable business, the paper conducted a survey on the study of business models and, in particular, sustainable business models (e.g., eco-innovations, sustainable innovations, product-service systems). The survey focuses on how the study models external environment and its influences on the core business characterized by "externality". Through discussion on the findings of the literature review, three key issues to be addressed for constructing sustainable business model are identified: taxonomy of externality, identification of a set of models (i.e., aspect model), and identification of interrelationship among them. First and second issues clarify particular aspects of externality. By considering third issue, the designer is able to design sustainable business by integrating these aspects. © 2014 Published by Elsevier B.V.

東日本大震災以降，発電機能を持つコージェネレーションシステム(CGS)が注目されているが，その優位性は将来の社会状況によって異なる．本研究では集合住宅を対象として，異なる社会状況下でのCGSの優位性を評価するために，複数の将来シナリオを作成する．作成したシナリオを環境性，経済性の観点から評価した結果，CGSの利用によって系統電力負荷のピークを大幅に削減できる可能性のあることが明らかとなった．

This paper proposes a design support method for increasing the recyclability of electrical and electronic products. The method estimates the recyclability rate and the disassembly time of a product based on its material composition and endof- life scenario. Sensitivity analysis is conducted on the recyclability rate in order to quantify the impact of design changes in the product's material composition, mass of components, and end-of-life treatment processes. For the feasibility check of the design changes, we introduce a structural model of the product, which represents the geometric constraints among components to assess their disassemblability. As a case study, the recyclability of a LCD TV with an end-of-life scenario in Europe was evaluated and sensitivity analysis on the TV generated design alternatives that increase the recyclability rate while keeping the disassembly time of the original design.

Within the framework of sustainability in manufacturing industry, product lifecycle design is a key approach for constructing resource circulation systems of industrial products that drastically reduce environmental loads, resource consumption and waste generation. In such design, designers should consider both a product and its lifecycle from a holistic viewpoint, because the product's structure, geometry, and other attributes are closely coupled with the characteristics of the lifecycle. Although product lifecycle management (PLM) systems integrate product data during its lifecycle into one data architecture, they do not focus on support for lifecycle design process. In other words, PLM does not provide explicit models for designing product lifecycles. This paper proposes an integrated model of a product and its lifecycle and a method for managing consistency between the two. For the consistency management, three levels of consistency (i.e., topological, geometric, and semantic) are defined. Based on this management scheme, the product lifecycle model allows designers to evaluate environmental, economic, and other performance of the designed lifecycle using lifecycle simulation. Copyright © 2013 by ASME.

This paper proposes a design support method for improving the recyclability of electronic and electrical products. The method estimates the recycling rate of a product based on its end-of-life scenario. The method supports a designer in generating design alternatives that increase the rate by conducting impact analysis with the change of material composition and end-of-life scenario. The method suggests design alternatives with the constraint of keeping the other performance factors (e.g.; flexural strength and thermal conductivity) constant by adjusting the geometric parameters (e.g.; thickness and volume) of the components. © 2013 CIRP.

Differences in legislation and markets for recycled materials result in the national implementation of distinct end-of-life treatment strategies. This paper presents a comparative analysis of the boundary conditions in Belgium and Japan that cause the adoption of diverse treatment strategies for the rapidly increasing number of end-of-life flat screen TVs. In addition, both treatment strategies are evaluated from an ecological and economic perspective and opportunities for improvement are identified. © 2013 CIRP.

There are a number of long-term scenarios toward envisioning a sustainable society, particularly a low-carbon society. While such scenarios often assume various low-carbon technologies with an aim to reduce greenhouse gas emissions, it is unclear whether the scenarios are feasible from the viewpoint of resource depletion. For example, copper is a critical base metal since introducing low-carbon technologies (e.g., electric vehicle and wind power generator) may induce copper consumption. This paper proposes a method for estimating long-term metal demand based on sustainability scenarios. Our method proposes an integrated model that evaluates world metal demand from two different perspectives - (1) economic development and (2) dissemination of new products, e.g., electric vehicles. As a case study, the feasibility of a long-term energy scenario is assessed from the viewpoint of copper depletion. Results illustrate that the cumulative copper consumption exceeds the copper reserved in the earth by around 2040. The increase in copper consumption results mainly from world economic growth led by developing countries, while the dissemination of electric vehicles has a minor impact on the consumption increase.

Toward realizing a low-carbon society, a variety of green products have been disseminated, such as photovoltaics (PV) and electric vehicles (EVs). While the dissemination of such green products will result in changes of electricity demand in a region, it is unclear to what extent the dissemination of these products will influence on regional electricity networks (or electrical grids) in the future. To explore regional electricity networks that might occur in the future, this paper describes plural scenarios that illustrate different situations in terms of the diffusion of PV and EVs. A simulation model is developed for estimating the diffusion of PV and EVs as well as regional electricity demand. As a case study, five scenarios of regional electricity networks in Toyonaka City, Osaka, Japan are described assuming the year 2030. The results demonstrate that the numbers of PV and EVs largely differ depending on social situations surrounding the electricity networks, such as national energy policies. Moreover, it is shown that utilizing EVs as batteries has the potential of reducing the peak of electricity demand from the electricity network by 46-48%.

In the life cycle engineering, describing scenarios is considered a good approach to sustainability in manufacturing in terms of clarifying visions of future manufacturing industry. When envisioning sustainable futures, describing &quot;backcasting&quot; scenarios is especially hopeful, because in a backcasting scenario, ideal future visions are firstly developed apart from the present situation. Although many scenario development methods have been proposed, these methods are too abstract, especially have no specific procedure for designing backcasting scenarios. This paper proposes a method for supporting design of backcasting scenarios using logic trees. In this method, logic trees support determining the structure of a backcasting scenario and creating storylines, which are outlines of sub scenarios. The logic tree and the storylines support describing the scenario text. As a case study, we described a backcasting scenario on &quot;breakdown&quot; of Japanese manufacturing in 2050. The result of the case study revealed that the logic tree systematically supports determining the structure of this scenario and generating its storylines. And composing scenario text is successfully supported by detailing the logic tree and the storylines.

© 2012, Fukushige et al; licensee Springer. This paper proposes a method for supporting the design of product lifecycles. The main approach involves supporting designers in determining a lifecycle strategy by describing lifecycle scenarios at an early stage of lifecycle design. The authors define a representational scheme for the lifecycle scenario and outline a support system based on the idea of the Cognitive Design Process model allowing the designers to examine various possibilities of lifecycle strategy. A number of alternative scenarios are managed by the Truth Maintenance System implemented in this approach. Finally, in order to embody the strategy in the later stages, the system derives requirements for product and process design. This paper outlines the lifecycle scenario of a cellular phone as a case study, which indicates the system's suitability for computer-aided description of scenarios and its facilitation of lifecycle strategy development.

Developing scenarios is a hopeful approach for drawing visions and pathways of sustainable manufacturing toward sustainable society. Sustainable Society Scenario (3S) Simulator is an integrated design support environment that supports understanding, describing, and analyzing scenarios. This paper proposes a design support method of scenarios in 3S Simulator. Proposed method supports designing scenarios in forecasting manner, in which futures are explored starting from the present. We employ two-leveled causal networks for supporting scenario design in structuring ideas and describing the structured ideas into a scenario, by expressing the structure of the object world of the scenario. In the case study, we verified that the outlines and details of a scenario are deployed from the causal networks. Using 3S Simulator, the relationship between the causal networks and the descriptions of a scenario is clarified. This supports a designer to understand the scenario rationally. As the conclusion, proposed method supports designing scenarios in forecasting manner.

In order to increase value and reduce environmental loads and resource consumption over the entire product life cycle, a designer should design a product life cycle as well as a product in an integrated manner. In order to support such integrated life cycle design, we are currently developing Life Cycle CAD (LC-CAD) system. Indispensable requirements for LC-CAD system include the following three points: (1) Representing a product and its life cycle in an integrated manner, (2) Managing the consistency of the relationship between a product and its life cycle, and (3) Life cycle evaluation by using the information of a product and its life cycle. This paper focuses on the function (1) and (2), and proposes a method of consistency management between a product and its life cycle. For this purpose, this paper proposes a method for representing a product and its life cycle with defining the relationship between these two models. Then, this paper proposes a management scheme for the consistency of the relationship. We developed a prototype systemand applied it to design of Liquid Cristal Display (LCD) TV as a case study. The result indicates that the relationship between a product and its life cycle is successfully represented and managed, and that a designer can design them in an integrated manner.

As global environmental issues have become aggravated, "Eco" has become a competitive advantage in business because of consumers' increasing environmental consciousness. However, it is difficult to lead an eco-business to success in both environmental and economic aspects. In order to solve these problems, this paper proposes a methodology that supports ecobusiness planning, in which a design team utilizes the eighteen rules to generate ideas for eco-business based on the investigation of 50 cases of existing ecobusiness, combines these eco-business ideas to generate eco-business model prototypes, and modifies them. This paper also verifies the feasibility of the proposed method through a workshop. The results of the workshop revealed that the method effectively supports especially in generating eco-business ideas by using the eighteen rules, combining ideas with other ideas, and evaluating them from the three perspectives of market attractiveness, company suitability, and environmental consciousness.

Minimizing environmental loads and costs throughout a product lifecycle requires appropriate lifecycle design. Design of a product lifecycle involves planning lifecycle strategies, evaluating them from various viewpoints and optimizing the overall picture. Product lifecycle strategy can be planned explicitly by describing lifecycle scenarios at an early stage of lifecycle design and the product should be designed to realize the scenario. This paper proposes a design environment for scenario-based lifecycle design. The main approach is to define a representational scheme of a product and its lifecycle in order to integrate them. Our method links a lifecycle model to appropriate product architecture and manages the consistency between them. A case study indicates that the relationship between the lifecycle and the product model is successfully represented on a computer and designers can design a product and its lifecycle in an integrated manner.

近年，地球環境問題に対する取り組みとして，省エネルギー技術，再生可能エネルギー技術の開発が進められている．しかし，それらが導入された社会におけるエネルギー需給の状況は不明確である．その不明確な将来に対処するため，将来エネルギー需給シナリオを作成する．その作成支援システムとして，将来シナリオシミュレータを提案する．本稿では，シナリオの一例として作成した「豊中市CEV普及シナリオ」について報告する．

Various sustainability scenarios visualize images of a sustainable society. For example, the IPCC's scenario aims to describe images of a low-carbon society. These sustainability scenarios often suppose introducing new technologies (e.g., electric vehicles (EVs)) to reduce energy consumption and greenhouse gas emissions. However, the depletion risks of metals are not evaluated in those scenarios. This paper proposes a method to evaluate depletion risks of metals by estimating future metal consumption. We estimate the consumption considering three factors: (i) economic growth, (ii) diffusion of new products (e.g., EVs), and (iii) effect of recycling. As a case study, we take copper as an example metal and estimate copper consumption based on a long-term energy scenario. The results show that, although recycled copper reduces more than 20% of annual consumption, cumulative consumption surpasses the reserve base of copper by 2050. © 2012 Fraunhofer IZM.

A variety of new products, such as photovoltaic (PV) systems and electric vehicles (EVs), have been introduced to electricity systems targeting an energy-saving and low-carbon society. However, it is still unclear that, when these energy-saving products will be disseminated in our society, the dissemination will influence future electricity systems. To explore how future electricity systems might unfold, this paper describes scenarios by analyzing the influence of the diffusion of energy-saving products; e. g., PV systems and EVs. We compose the scenarios of regional electricity networks by combining scenario texts and simulations. The simulations estimate products diffusion and electricity demand based on the assumptions described in the scenario texts. We analyze the influences of introducing especially PV systems and EVs into electricity networks using the simulation models that we developed. As a case study, we described the scenario of a suburb city in Osaka, Japan.

When companies plan long-term strategies for making their business sustainable, designing scenarios is a promising way for examining various business strategies by drawing various possible situations in the future. This paper proposes a method to support scenario design for planning business strategies. The method employs existing sustainability scenarios, helping describe business environments by reusing descriptions of the sustainability scenarios. A scenario about solar panel business is described using the proposed method. Results illustrate that the method succeeds in describing detailed business environments based on existing sustainability scenarios, and finally, in obtaining several business strategies based on the business environments.

Designing sustainability scenarios is a promising approach to describing visions and transitions of the manufacturing industry targeting a sustainable society. However, computational assistance in designing such scenarios is not sufficiently provided in the current scenario research. This paper proposes a method for drawing scenario variants by executing what-if analysis of existing scenarios in order to explore different possible futures in the scenario design process. To support composing scenario variants, the method defines scenario rationales that should be changed in the process of what-if analysis. Results of a case study involving an existing sustainability scenario show that the method successfully helps draw a new scenario variant by modifying a part of the rationales of the original scenario. Consequently, 82% of the texts of the new scenario are described from the original scenario.

One of the effective approaches for increasing resource efficiency of products is to improve their recyclability in consideration of their product life cycles at the design stage. To support product design for recycling, this paper proposes recyclability evaluation method by following two steps; (1) to describe an end-of-life scenario of a product, (2) to calculate recyclability rate of the product based on the described end-of-life scenario. As a case study, we evaluated recyclability of three LCD TVs. The result showed that recyclability of a product depends on its end-of-life processes as well as the material constitution of the product.

In product life cycle design, a designer should design both a product and its life cycle. Although CAD systems for product design are popular, there are no CAD systems for life cycle design. This paper proposes LC-CAD (Life Cycle-CAD) that represents a product and its life cycle in an integrated manner, manages consistency between these two models, and describes changes of a product along its life cycle (e.g., a component is shredded into fragments of metal in a recycling process). LC-CAD also evaluates environmental, economic, and other performance of designed life cycle using life cycle simulation. © 2012 CIRP.

Manufacturing companies encounter many uncertainties in planning long-term strategies for making their business sustainable. As a decision-making tool in the business world, scenario writing is prevalent for exploring various business strategies by drawing various situations that might unfold in the future. The purpose of this paper is to propose a method for supporting the design of scenarios for planning long-term business strategies. In this method, such scenarios are described using existing sustainability scenarios. The method intends to help companies' strategists describe business environments by reusing and extending descriptions of sustainability scenarios. A scenario about solar panel business is described using the proposed method. The results illustrate that the method succeeds in describing detailed business environments from an existing sustainability scenario, and finally, obtaining several business strategies based on the business environments. In addition, our method clarifies the logical structure of the scenario, thereby enabling to review rationales for deriving those business strategies.

Describing sustainability scenarios is a hopeful approach for envisioning sustainable future visions of industries. However, describing sustainability scenarios is a difficult task and there is no computational support method. This article proposes a design support method of sustainability scenarios in a backcasting manner, which means thinking backward from targeted futures. For the design support method, we propose the following two methods;(i) a method for supporting backward thinking and constructing future visions using a logic tree and (ii) a method for drawing transition paths based on the logic tree. As a case study, we designed "Sustainable manufacturing scenario,"which envisions sustainable future visions of manufacturing industries. Through the case study, we identified the effectiveness of the proposed method. The proposed method supports designing the scenario in clarifying the future visions, drawing the transition paths, and describing them in scenario structurally. © 2012 by ASME.

A variety of sustainability scenarios (e.g., IPCC's Emissions Scenarios) have been described toward a sustainable society. While many of them aim at solving climate change problems and they often assume various low-carbon technologies, the problem is that such scenarios hardly examine their feasibility from the viewpoint of resource depletion. In particular, copper is a critical base metal because introducing low-carbon technologies (e.g., electric vehicles and wind power generators) may induce copper consumption. To assess feasibility of existing sustainability scenarios, this paper proposes a method for estimating long-term copper demand based on those scenarios. Our method proposes an integrated model that evaluates world copper demand from two principal aspects of influencing copper consumption - (1) the building of social infrastructure and (2) new products that might disseminate in the future (e.g., electric vehicles and photovoltaic systems). A case analysis on a long-term energy scenario is carried out. Its results reveal that the cumulative copper consumptions in the world exceed the copper reserved in the earth by 2040. The increase in copper consumptions results mainly from world economic growth led by developing countries, while the dissemination of electric vehicles and photovoltaic systems has a minor impact on the consumption increase. © 2012 by ASME.

As global environmental issues have become aggravated, &ldquo;Eco&rdquo; become one of competitive advantages in the business because of increasing consumers' environmental consciousness. However, it is difficult to lead eco-business to the success in both of environmental and economic aspects because of three features of eco-business; external diseconomies, unrecognition of environmental value in the market, requirement for restructuring of business model. For solving this problem, it is effective to support finding out Eco-business ideas. The purpose of this study is to propose the methodology that supports generation of eco-business ideas. This paper proposes the methodology, which has 8 steps, such as generation, settling, evaluation, through the investigation of eco-business and makes sure of its effectiveness through workshop.

Manufacturing companies encounter many uncertainties in planning long-term strategies for making their business sustainable. As a decision-making tool in the business world, scenario writing is prevalent for exploring various business strategies by drawing various situations that might unfold in the future. The purpose of this paper is to propose a method for supporting the design of scenarios for planning long-term business strategies. In this method, such scenarios are described using existing sustainability scenarios. The method intends to help companies&#039; strategists describe business environments by reusing and extending descriptions of sustainability scenarios. A scenario about solar panel business is described using the proposed method. The results illustrate that the method succeeds in describing detailed business environments from an existing sustainability scenario, and finally, obtaining several business strategies based on the business environments. In addition, our method clarifies the logical structure of the scenario, thereby enabling to review rationales for deriving those business strategies.

Although there are many scenario description methods, computational support has not been provided for scenario design. This paper proposes a method for supporting design of forecasting scenarios. This method supports determining storylines, which are key assumptions of sub scenarios, and describing sub scenarios based on the causal network and storyline. As a case study for verifying feasibility of this method, we described a forecasting scenario about changes of automobile industry when electric vehicles are diffused. Results illustrate that the usage of causal networks effectively supports generating storylines. Also, describing scenario texts is supported by detailing causal networks and the storylines.

Life Cycle Management (LCM) has established as research area to foster sustainability in all fields of action of organizations. To provide an understanding for this broad research area suitable teaching methods are required. This paper presents the concept for a business game based on the Framework for Total Life Cycle Management (TLCM). It enables participators to understand the interdependencies of four different management disciplines: product, production, after sales and end-of-life management. The educational objective is to continuously develop a holistic life cycle strategy. The game requires communication of all actors and reasonable activities towards sustainability. By that prospective managers can understand relationships and interdependencies of TLCM.

In order to solve global environmental issues, we should construct stable circular product lifecycle systems. For this purpose, lifecycle design plays a crucial role; especially, it is necessary to determine lifecycle strategies at the early stage of lifecycle design. In the current practice of eco-design, for example, a designer increases the disassemblability of a product for recycling, although the product is shredded without disassembling. For avoiding such a situation and realizing stable circular product lifecycle systems, appropriate lifecycle strategies should be determined and implemented by designing both a product and its processes. This paper proposes a method for supporting design of a product lifecycle. The main approach is to support a designer to determine a lifecycle strategy by describing a lifecycle scenario, at early stage of lifecycle design. We define a representational scheme of the lifecycle scenario and develop the support system based on the idea of cognitive design process model so that a designer can examine various possibilities of lifecycle strategy. After this stage of lifecycle design, the product and its lifecycle processes should be designed so as to realize the strategy. In order to embody the strategy in the later stages, the system derives requirements for the product and process design. A case study indicates that the lifecycle scenario is successfully represented on a computer and a designer can easily determine lifecycle strategies by using this system. Copyright © 2011 by ASME.

Environmental problems such as resource depletion and climate change are the most serious problems for society and industry. In order to deal with such problems, scenario writing is a useful methodology for envisioning ideal future, such as sustainable society. Although describing these scenarios requires a lot of time and a large amount of work, there is no computational support for it. In order to resolve this problem, this paper proposes a design methodology of scenarios based on forecasting approach, which explores future from current situation. In order to realize computational scenario design support, we formalize the design process as four steps; setting problems, constructing causal networks, describing storylines, and describing scenario texts. And we develop Scenario Design Support System for supporting the scenario design process on a computer. For testing the proposed methodology, we designed "Electric Vehicle Diffused Society Scenario" as a case study. In the case study, proposed process and design support methodology were useful for designing a forecasting scenario. Copyright © 2002-2012 The Design Society. All rights reserved.

Numerous scenarios have been developed in order to create visions of a sustainable society, such as the IPCC's Scenarios. However, sufficient computational assistance has not been provided for designing scenarios. One critical problem is that it is difficult to understand scenarios rationally since scenarios are written in a text form and their logical structure is unclear. For supporting computer-aided scenario design, this paper presents the concept of Sustainable Society Scenario (3S) Simulator. The key approach is to structure scenarios for computerizing them by representing a scenario structure as a directed graph. Based on this approach, this paper proposes a method for dynamically connecting scenarios with associated simulators for their reuse. A case study illustrates that our method clarifies the logical structure of a scenario, e.g., clarifying rationales for deriving conclusions. Also, the method succeeds in exploring alternative futures by changing assumptions in the scenario.

The manufacturing industry is faced with a challenge to create products with less environmental impact targeting a sustainable society. To cope with this challenge, sustainable design or ecodesign plays one of the most important roles. Manufacturers often use ecodesign checklists that are intended for obtaining eco-labels, such as Eco Mark in Japan, in order to support design improvements of products in terms of environmental consciousness. Eco-label checklists are, however, insufficient to support designing products rationally because the relationships between individual requirements of checklists and environmental impact are undetermined. This paper proposes a method for supporting assessment for ecodesign by developing a weighted checklist from a conventional eco-label checklist. This weighted checklist assesses the environmental performance of a product based on the potential environmental improvement of each requirement, derived by life cycle simulation. Results of a case study involving a digital duplicator indicate that the proposed method successfully clarifies the requirements that should be improved in the present product. When the design improvements are applied, the assessment of the product's CO2 emissions shows an improvement by 8%. Copyright © 2010 by ASME.

Describing scenarios is a promising approach to draw images of manufacturing industry toward a sustainable society, whereas the images are still vague. Sustainable Society Scenario (3S) Simulator aims to support understanding, describing, and analyzing sustainability scenarios. This paper proposes a method for describing &ldquo;dynamic scenarios&rdquo; by connecting scenarios and their associated simulators. Our approach includes to structuralize scenarios for clarifying the relationship between a scenario and its simulators and to develop a mechanism of exchanging data between them. A case study illustrates that the proposed method succeeds in articulating rationales, described as texts in a scenario, for input data of a simulation. Also, the simulation results are successfully changed by changing simulation assumptions in the original scenario. The case study indicates that, as a result, the method enables to reuse a scenario and its simulator simultaneously.

Ecodesign plays one of the most important roles in manufacturing sectors towards a sustainable society. As a practical tool of ecodesign, manufactures often use checklists to support product design as well as to obtain eco-label certification. However, current checklists are insufficient due to undetermined effects of individual requirements in the checklists on environmental impact. This paper proposes a method for supporting ecodesign assessment by developing a weighted checklist, where potential environmental improvements in each requirement are derived based on the life cycle simulation. In the case study involving a digital duplicator, the proposed method successfully identified requirements that needed to be improved. When suggested improvements were applied, 8% of total CO₂ emissions were estimated to be reduced.

Abstract: A considerable amount of resources is exchanged among Japan and other Asian countries. We call it 'global circulation'. Although such circulation currently causes various environmental pollutions, it will become a hopeful measure for resource conservation. For clarifying the conditions for sustainable global circulation, we evaluate several scenarios of the global circulation from the viewpoints of economic and environmental aspects. When modelling the global circulation, we inevitably encounter two types of uncertainty, i.e. unexpected events and insufficient practical data. This article represents such uncertainty as risks and data width. The simulation results indicate that a product reuse scenario is the most promising for the sustainable global circulation. Concerning recycling scenarios, the risks are higher than those of reuse scenarios. This article also points out that the traceability, one of the most crucial elements for constructing the sustainable global circulation, can be measured by the risks.copyright © 2009 inderscience enterprises ltd.

Life cycle design requires planning of a product life cycle in addition to designing of a product. One of the effective methods to plan the product life cycle is to describe a life cycle scenario, which should be then realized by designing the product and its life cycle processes. This paper proposes an integrated design method to support the life cycle design comprehensively. Especially, we propose a design system that supports a designer to describe the life cycle scenario and to design the product based on the scenario in an integrated manner.

Although modular design is a key technique for lifecycle design, effectiveness of modularity on environmental consciousness is not clear. This paper proposes an evaluation method of modular product from the viewpoint of resource efficiency. First, a product is modularized by applying our modularization method based on its lifecycle scenario. Second, the modular structure is evaluated by assuming that each module goes through preferable lifecycle paths (e.g., upgrading, reuse, and closed-loop recycling) designated by the scenario but unmodularized components go through unpreferable paths. This paper also illustrates a case study in order to discuss effectiveness of the proposed method. © 2009 CIRP.

Although the life cycle engineering aims at 'sustainability', its image is still unclear. While various scenarios have been proposed for this purpose, their rationality and assumptions are not clearly described because they are just documents referring some simulation results. For analyzing and composing the scenarios, this paper proposes the framework of 'Sustainable Society Scenario (3S) Simulator' and a methodology for structural representation of scenarios. This paper also demonstrates a prototype system and its structural representation of the IPCC scenario. The representation clarified the basic structure of this scenario and highlighted a set of assumptions as the base of this scenario. © 2009 CIRP.

Environmentally conscious design or ecodesign is a key methodology to achieve the sustainable society. Manufactures often use ecodesign checklists to improve their products; however, the relationship between individual requirements of checklists and environmental impact is undetermined. This paper proposes a method for assessing ecodesign achievement by developing a weighted checklist from a conventional checklist. The ecodesign achievement is defined as potential environmental improvement, evaluated by the life cycle simulation. An example involving a digital duplicator shows that the proposed method clarifies requirements to be improved. When applying design improvements, the assessment of the product's CO2 emission decreases by 8%.

A product's lifecycle can be described explicitly as a lifecycle scenario, and the product should be designed to realize a scenario that minimizes its environmental load over the entire product lifecycle. This paper proposes a method of modular design that links the lifecycle scenario to appropriate product architecture by modularizing components that are suitable for the same life cycle options such as recycling, maintenance, reuse and upgrade. We also propose an index for evaluating and comparing efficiency in resource circulation for modular products derived from various life cycle scenarios.

Environmentally conscious design or ecodesign plays one of the most important roles to create products with less environmental impact targeting the sustainable society. Manufactures often use checklists to support design improvements of products and to obtain eco-labels, such as Eco Mark in Japan. Current checklists are, however, insufficient to support designing products rationally because the relationship between the individual requirements of current checklists and environmental impact is undetermined. This paper proposes a method for supporting ecodesign assessment by developing a weighted checklist from a conventional checklist. This weighted checklist calculates ecodesign achievement based on the potential environmental improvement of each requirement, derived by the life cycle simulation. The result of a case study involving a digital duplicator showed the proposed method successfully clarified requirements that should be improved in the present product. When design improvements are applied, the assessment of the product's CO2 emission is improved by 8%. Copyright © 2009 by ASME.

Minimizing the environmental load and cost throughout the product lifecycle requires appropriate lifecycle design as well as product design. Product lifecycle can be designed easily by describing lifecycle scenario at an early stage and the product should be designed to realize the scenario. This paper proposes a modular design method that links lifecycle scenario to appropriate modular structure by unifying components applicable to the same lifecycle option, such as recycling, maintenance, reuse, and upgrading. Appropriate modular structures may differ with the lifecycle options, meaning that while the modular structure for recycling should be based on the type of material, the structure for upgrading should be based on the lifetime of components. The modules, therefore, can undergo lifecycle processes without disassembly into components. These may lead to easy management of components throughout the lifecycle and increase the efficiency of recovery processes and logistics in resource circulation. We also propose an evaluation method of modular product from the viewpoint of resource efficiency. For the evaluation, we formalize the probability that each module goes through preferable lifecycle paths designated by the scenario in order to represent the advantage of modularization. This paper also illustrates a case study in order to discuss effectiveness of the proposed method. Copyright © 2009 by ASME.

Today, many scenarios are described for envisioning sustainable society such as the IPCC's Emissions Scenarios. These scenarios often employ simulators to provide a basis for their descriptions. However, existing scenarios do not explicitly describe the relationship between scenario document and simulators, e.g. its simulation conditions. This spoils reusability of scenarios. We propose a scenario design methodology to describe sustainable society scenario efficiently and effectively. We are developing Sustainable Society Scenario (3S) Simulator to support scenario design process. This paper proposes a method for making new scenario variants efficiently by reusing existing scenarios and simulators. In order to realize proposed method, we define a structural description method of scenarios for connecting scenarios with their simulators dynamically and we develop a data managing tools as components of 3S Simulator to modify scenarios by using proposed method. In a case study, scenario structure including simulator is clearly represented and we succeeded in describing new sub scenario easily by reusing existing scenario and simulator.

Modular design is an important elemental technique in life cycle design. Modularity may increase maintainability, upgradability, and so on. Appropriate modular structure differs according to applied life cycle options; e.g., while the modular structure for recycling should be based on material kinds, the structure for upgrading should be based on functions to be obsolete. This paper proposes a modular design methodology that derives modular structures flexibly depending on applied life cycle options by utilizing the attributes of components and geometric model. The components are classified into some groups according to the similarity of attributes and the geometric information is employed to derive a geometrically feasible modular structure within the group. This paper also illustrates the prototype system that implements the proposed method and a case study of a printer.

A variety of scenarios including the IPCC's Emissions Scenarios have been described toward achieving the sustainable society. Describing such scenarios is a hopeful approach for drawing future images of sustainable manufacturing. However, there exist difficulties in understanding these scenarios rationally since their logical structure is ambiguous. This prevents us from relying on these scenarios and describing new scenarios by using existing scenarios. In order to support understanding, analyzing, and describing scenarios, this paper proposes the concept of Sustainable Society Scenario Simulator (3S Simulator). As the first step, this paper proposes a method for describing scenarios structurally for a rational understanding of scenarios. This method expresses a scenario in four levels; i.e., Scenario, Expression, Word, and Data Levels. Particularly, this paper focuses on Scenario and Expression Levels and formulates the &ldquo;base&rdquo; of a scenario to clarify rationales that logically support its conclusions. The results of a case study involving World Energy Outlook 2004 showed that the proposed method successfully clarifies the logical structure of the scenario and identifies its base of the rationale. In this scenario, it was revealed that many of conclusions are derived beyond logicality since the scenario inevitably contains future predictions.

In order to minimize environmental loads and costs during a whole life cycle of a product, adequate life cycle design as well as product design is indispensable. In life cycle design, the anticipated life cycle of a product can be clarified by describing a life cycle scenario. Modular design is an important elemental technique to link life cycle design to appropriate product architecture, and improves, e.g., maintainability, upgradability, reusability, and recyclability by unifying components applicable to the same life cycle scenario. This paper proposes a modular design method based on various attributes related to a product life cycle scenario; e.g., while the modular structure for recycling is based on material kinds, the structure for reuse is based on lifetime of components. Furthermore, we define an evaluation index for evaluating derived modular structure from the viewpoint of resource efficiency. This paper also illustrates the prototype system that implements the proposed method and a case study of an ink-jet printer.

Modular design is an important elemental technique in life cycle design for improving, e.g., maintainability, upgradability, reusability, and recyclability. Appropriate modular structure differs according to applied life cycle options; e.g., while the modular structure for recycling should be based on material kinds, the structure for upgrading should be based on functions to be obsolete. This paper proposes a method for determining modular structure by aggregating various attributes related to a product life cycle and evaluating geometric feasibility of modules. This paper also illustrates the prototype system that implements the proposed method and a case study of a printer. © 2008.

Visibility determination is one of the oldest problems in computer graphics. The visibility, in terms of back-to-front polygon visibility ordering, is determined by updating a priority list as the viewpoint moves. A new list-priority algorithm, utilizing a property of Voronoi diagrams, is proposed in this paper. The operation is in two phases. First, in a pre-processing phase the scene is divided into Voronoi cells. A sub-list associated with each cell contains references to those polygons that intersect with it. The polygons are assigned a fixed set of view-independent priority orders within the cluster. Last, an interactive phase sorts the clusters according to the depth value of each Voronoi site. The most time-consuming work is performed during the pre-processing phase that only has to be executed once for the scene. Since all the polygons in a cell are pre-computed to obtain the fixed priority order within the cluster, a relatively simple task is left in the interactive phase, which is only to sort the clusters repeatedly when the viewpoint is changed. This method contains performance benefits that make it better shaped than previous BSP based methods. © Springer-Verlag 2007.

In these days, modular design of a product is becoming important even for environmental conscious design in order to improve, e. g., reusability, disassemblability, and recyclability. In order to derive a feasible module structure, not only environmental aspects but also geometric information bears important roles. This paper presents a modular design methodology for life cycle engineering that proposes module structure by using information on geometry and product life cycle. The case study of an inkjet printer revealed that the derived modular structure satisfies the various demands from product life cycle with keeping the geometric consistency.

This paper proposes a method for describing product life cycle scenario and a description support system for the life cycle scenario. Our idea is that a designer can determine the life cycle strategy easily by describing the life cycle scenario at the early stage of life cycle design. We define a representational scheme of the life cycle scenario and develop the support system by using the idea of the design rationale. As a result, it is clarified that the life cycle scenario is successfully represented on a computer and a designer can easily determine the life cycle strategy by using this system.

Increasing productivity of resources is a major approach in the framework of sustainability in manufacturing. The manufacturing industry can reduce the consumption of resources and production of waste by applying more efficient design techniques. We focused on simplifying the structure of a product as the key method of design for environment. The removal of redundant components, by extracting the ideal simplified structure, decreases manufacturing costs and, at the same time, increases the resource productivity. We propose a methodology for product simplification that can be applied to general products and developed a product design support system by using information on the geometry and the connectivity of the product's components. A case study based on models of a vacuum cleaner and an inkjet printer showed the effectiveness of the methodology.

Visibility determination is one of the oldest problems in computer graphics. The visibility, in terms of back-to-front polygon visibility ordering, can be determined by updating a priority list as the viewpoint moves. A new list-priority algorithm, utilizing a property of Voronoi diagrams, is proposed in this paper. In the preprocessing phase, the 3D space is divided into Voronoi cells in order to cluster polygons that can be assigned a fixed set of priority orders within the cluster. and during the post-processing phase, the clusters and contained polygons are depth-sorted correctly. The most time-consuming work is undertaken during the pre-processing phase that only has to be executed once for the scene. All the polygons in a cluster are pre-computed to obtain the view independent priority order within the cluster. Thus, a relatively simple task is left in the post-processing phase, which is only to sort the clusters repeatedly when the viewpoint is changed. One reason to explore list-priority algorithm is because they offer flexibility that hardware configuration (such as Z-buffer approach) do not possess. One example is that of rendering with the correct treatment of the translucency effects. Translucency is an important graphics effect that can be used to increase the realism of the rendered scene or to enable more effective visual inspection in visualization.

We propose a system that uses a camera and a mirror to input behaviour of a pointer in 3D space. Using direct and reflection images of the pointer obtained from single directional camera input, the system computes the 3D positions and the normal vector of the mirror simultaneously. Although the system can only input the "relative positions" of the pointer, in terms of 3D locations without scale factor, calibration of the mirror orientation is not needed. Thus, the system presents a very simple and inexpensive way of implementing an interaction device.

We propose a system that uses a camera and a mirror to input behaviour of a pointer in 3D space. Using direct and reflection images of the pointer obtained from single directional camera input, the system computes the 3D positions and the normal vector of the mirror simultaneously. Although the system can only input the "relative positions" of the pointer, in terms of 3D locations without scale factor, calibration of the mirror orientation is not needed. Thus, the system presents a very simple and inexpensive way of implementing an interaction device.

Computer systems are widely used in mechanical design process, but their user interfaces and devices are not sufficient for designers to create sophisticated shapes. Various kinds of 3D input devices are not so useful either in terms of functions and costs. We propose a vision based interface called "Elastick" using an elastic stick and a digital camera which allows a designer to input smooth spatial curve very easily. It does not require any expensive, special devices and environments. The designer bends the stick to form a desired spatial curve. A digital camera is used to take an image of the stick, from which a spatial curve is reconstructed. A method developed by Pentland(PENTLAND, 1989) is used to reconstruct a spatial curve from a single image. In this paper, methods and algorithms used for Elastick are described and its application for generating mesh models are demonstrated.