Shinsuke Kondoh

Development of design methodology for upgradable products based on function–behavior–state modeling

Extending product life is one of the hopeful approaches to reduce the environmental issue, which is one of the most critical issues of today. However, many products are thrown away because of obsolescence of functions and their performance. Therefore, we should design products to be functionally upgradable. Moreover, such upgradable products may create business chances at later stages of product life cycles. The objective of this research is to propose a design methodology for upgradability. This methodology employs a functional modeling scheme, FBS modeling, because upgrade design is a distinctive application of functional design that aims at maximizing functional flexibility with minimal structural changes after the product is manufactured. Here, the functional flexibility refers to an ability of a product to adapt its functions to changes of user needs. This paper proposes and models design processes and design operations in the upgrade design. Especially, the methodology supports finding out candidates of modifications of the function structure and configuration of a platform, which is common structure of a product among several generations, and upgrade modules. One of its central issues of upgrade design is treatment of future uncertainty. For this purpose, we propose two design strategies: delayed selection of components, and expanding and shrinking platform. A prototype system and a case study of upgrade design for a vacuum cleaner are also illustrated. The case study indicates that the system succeeded in systematically supporting a designer to execute the design methodology. Regarding the functional design, as an extension of FBS modeling, this paper proposes a method to relate abstract entity concepts in FBS modeling to concrete components through a quantitative behavior model and range calculation, in addition to deployment of FBS modeling for the design methodology.

Total performance analysis of product life cycle considering the deterioration and obsolescence of product value

Environmental consciousness has gained more and more interest in recent years, and product life cycle design that aims to maximise total performance while minimising its environmental load and costs should be implemented. To achieve that, the rise and fall in product value along life cycles should be evaluated properly. This paper proposes a practical evaluation method for the product value along life cycle by correlating it with product functionalities, and design guideline for maximising product performance through product life cycle with balancing its value, environmental load, and costs.

Analysis of Reusability using ‘Marginal Reuse Rate’

Abstract While reuse is an effective lifecycle option in terms of reduction of environmental loads and value of reutilization, reuse has inherent difficulties. Our naive question is why component reuse of home appliances seems impossible while that of photocopiers succeeded. This paper clarifies an essential factor for successful reuse; that is, the balance between supply and demand of reusables, and proposes an index named ‘marginal reuse rate,’ which indicates upper limit of reusability. By using this index, reusability of several products is analyzed. The marginal reuse rate indicates that design of lifecycle, in addition to product design, is indispensable for successful reuse.

Analysis of key success factors for eco-business through case studies in Japan

In order to solve environmental issues, transition form conventional business to environmentally conscious business (Eco-business) is eagerly required. In order to promote Eco-business, it will be effective to support finding out Eco-business ideas. To do so, this paper takes an approach that provides business designer with general rules and prerequisites extracted from existing Eco-businesses. This paper collects 130 examples of Eco-businesses in Japan, investigates and classifies them to develop general guidelines and checklists for success of them. As a result, four customer’s values provided by Eco-businesses, eight rules that relates an environmental benefits of the society to the customer’s value, and eight rules for reducing business costs are derived. A tool for planning for new eco-business is also proposed.

Design for upgradable products considering future uncertainty

Conventional products tend to be thrown away because of functional obsoleteness before reaching the end of the physical life of the products. This is one of the main causes of the mass disposal problem. In order to solve this problem, the paper proposes a design methodology for upgradable products. In particular, the paper discusses a method dealing with uncertainty caused by long-term planning in the design methodology for upgradability. The proposed method deals with uncertainty as ranges of parameter values, and derives a design solution that realizes required upgrades, while adapting to estimated uncertainty. This method makes the products robust and tolerant against uncertainty, and therefore makes design for upgradability more feasible.

Development of Description Support System for Life Cycle Scenario

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.

Total performance analysis of product life cycle considering the uncertainties in product-use stage

Product life cycle design has gained more interest in recent years due to growing concern about environmental problems. In general, there exist significant uncertainties (e.g., operating condition, user preference, collection rate etc.) in product life cycle and a design method that is robust and tolerant against these uncertainties should be established. To this end, this paper discusses the uncertainties in product life cycle and evaluates their impact on total performance throughout a whole product life cycle. Based on this discussion, a design method for product life cycle that maximizes its total performance handling these uncertainties is proposed.

A simulation method of dynamic systems applied to backcasting scenario design

Companies and governments use scenarios as a means to express their long-term development plans from diverse, business, social, environmental, and technological aspects with various resolutions. In designing such scenarios, simulation methods are crucial in verifying scenario conclusions derived from facts and activities. This paper proposes a simulation method used in the scenario design process, which can deal with a scenario model with various resolutions by combining simulation methods studied on system dynamics and agent-based modeling. The method quantifies the side effects of target conclusions in backcasting design of a scenario towards sustainable society based on the IPAT formalization.

Total performance design of product life cycle considering future uncertainties

Product life cycle design has gained increasing interest in recent years due to growing concerns about environmental problems. In general, there exist significant uncertainties (e.g., operating conditions, user preference, post-consumer product collection rate, etc.) in the product life cycle, requiring a design method that is robust and tolerant against these uncertainties. To this end, this paper discusses design strategies for products and their life cycle to enhance total performance as a defence measure. Based on the discussion, a robust design method is proposed for maximising environmental and economic performance for the product life cycle. The effectiveness and feasibility of this method are demonstrated through a simple example of laptop computers.

Self Organization of Cellular Manufacturing Systems

Abstract Determining configuration of production facilities is a difficult problem. To solve this problem, the authors introduce the Cellular Manufacturing System as a rapid prototyping and strategic decision-making tool for configuring facilities and product task assignment. At the conceptual design stage of the cellular manufacturing system, there is no decision about facility configuration and product or machining task assignment. The configuration and assignment are determined by self-organization at the operation stage. This makes it possible for the cellular manufacturing system to decide strategic facilities configuration adapting to changing manufacturing requirements. This paper describes a model of the cellular manufacturing system and its self-organization algorithm through software simulation.