Using product family evaluation graphs in product family design

Product family design and platform-based product development have garnered much attention. They have been used to provide nearly customised products to satisfy individual customer requirements and simultaneously achieve economies of scale during production. The inherent challenge in product family design is to balance the trade-off between product commonality (how well the components and functions can be shared across a product family) and variety (the range of different products in a product family). Quantifying this trade-off at the product family planning stage in a way that supports the engineering design process has yet to be accomplished. In this paper, we introduce a graphical evaluation method, the product family evaluation graph (PFEG), that allows designers to choose the ‘best’ product family design option among sets of alternatives based on their performance with respect to an ideal commonality/variety trade-off determined by a company's particular competitive focus, and guides designers towards a more desirable trade-off between commonality and variety in an existing product family. Two necessary supporting pieces for developing the PFEG are also proposed. One piece is the development of commonality and variety indices to quantitatively capture the degree of commonality and variety in a product family and its functions and components. We introduce two sets of commonality and variety indices–the CDI (commonality versus diversity index) for commonality (CDI_C) and variety (CDI_V), and the CMC (comprehensive metric for commonality) for commonality (CMC_C) and variety (CMC_V)–to achieve this. The other supporting piece is the development of a quantitative representation of the ideal trade-off between commonality and variety in a product family, known as the commonality/variety trade-off angle α, based on the elements that characterise a company's competitive focus and their industry-wide competitors. A linear regression model is used to link the qualitative competitive focus to a quantitative engineering perspective, and then to estimate the ideal trade-off angle. The commonality/variety trade-off angle can then be applied to the PFEG to help designers evaluate a product family or compare product family design alternatives. Most importantly, the PFEG is not just the graph of the two sets of indices; it is the representation of the commonality/variety trade-off relative to the desired competitive focus. Four families of power tools are used to illustrate how the computation of such indices supports product family design evaluation in the PFEG. In this paper, we only use the CDI in the example application, but the CMC can be computed using the same approach.     

Modularity analysis and commonality design: a framework for the top-down platform and product family design

With a highly fragmented market and increased competition, platform-based product family design is recognised as an effective method for constructing a product line that satisfies diverse customer demand while keeping design and production cost- and time-effective. Recognising the need for modularity and commonality in platform development, this paper presents a systematic framework to assist in implementing top-down platform and product family design, which aims to achieve system-level modularity for variety generation, and rationalise the commonality configuration for module instantiation. In the first phase of platform development, a robust and flexible product family architecture is constructed to accommodate variations by analysing the external varieties of the generic product architecture, and provide a modularity design space, wherein the design tasks are further decomposed into module instantiation. The second phase of detailed platform development aims to enhance commonality in terms of engineering efficiency by coordinating with the back-end product realisation stage. A tractable optimisation method is used to capture and resolve the trade-off between commonality configuration and individual product performance. A family of power tool designs is used to demonstrate the potential and feasibility of the proposed framework at the system level and detailed design stages.     

Implications of product upgrading confronting supplier remanufacturing

It is generally believed that new products upgrading is an effective strategy to deal with the cannibalisation problem from remanufacturing, however, it is not clear how the new product upgrading strategy affect the decision-making of the downstream manufacturer and the upstream supplier. By examining the relationship between supplier remanufacturing profits and product cannibalisation, we develop two models to investigate the implications of the manufacturer's product upgrading confronting supplier remanufacturing. The results show that an product upgrading strategy can effectively enhance the manufacturer's profits if the investment cost is relatively low. Although the product upgrading strategy may hinder the remanufacturing operations, it will always be beneficial for the wholesaling of the supplier's new products. Therefore, the upgrading strategy can mitigate cannibalisation problems and create an optimal pareto improvement for both parties. Finally, we conduct a data analysis to provide additional managerial insights regarding the supply chain.     

Optimal configuration of remanufacturing supply network with return quality decision

This research studies the configuration problem of a remanufacturing production network together with the decision for return quality thresholds, in which, the manufacturer has multiple remanufacturing facilities to satisfy different market demands. Quality of returns is stochastic, while demand for remanufactured products is either stochastic or deterministic. The problem we considered is to determine facilities to operate, minimum quality to accept into each operating facility, return quantity and demand allocation simultaneously so that the system’s profit is maximised. The problem is formulated as a mixed integer non-linear programming model. Through the use of a numerical example, the impact of quantity of returns, total spending, quality uncertainty, demand uncertainty and transportation cost on the remanufacturing system is analysed.     

Review of supply chain configuration and design decision-making for new product

The nature of competitive markets continuously pushes manufacturers to develop new products to meet the increasingly diversified customer demands. Manufacturers thus have to handle the complexities generated during the total life cycles of various product types, from product design to procurement, production, marketing and recycling. Though some management practices in mass customisation help to improve the performance of manufacturing systems, there are still some fundamental problems not covered. Joint decision-making of product and supply chain design, for example, is one of them. The existing industrial practice tends to treat these two problems separately. Decoupling these two problems decrease the design complexity but may lead to suboptimal decision outcome. To enhance understanding of the interconnected decisions for supply chain management and product design, this review collects related literature on this topic and focuses on the analysis of existing papers from an operation research perspective.     

基于基因工程思想的产品族设计及其关键技术研究

通过分析型材断面的尺寸和形状特征的继承关系及型材模块的结构变异,将基因工程的思想用于产品族的开发设计中,并将"型材特征"看作是产品结构信息的"DNA"。借鉴生物学领域基因工程原理,揭示了"型材特征"这种信息流在产品树中的传播规律,在此基础上提出了一种基于基因工程思想的产品基因编码与重组方法。通过对产品族和产品基因DNA的概念以及产品族设计DNA的内涵和研究内容的探讨,指出了支持产品基因工程的关键技术,并以门体型材为例,说明产品族基因工程思想的设计效果。     

面向可适应性的产品平台设计参数规划方法

 在分析已有产品平台特点的基础上,将模块化和参数化产品平台统一表示为基于“设计参数”的产品平台,提出了面向可适应性的产品平台设计参数规划方法．引入可适应设计理念,分析了产品平台结构及变型方式;以公理设计理论为指导,进行产品功能要求 设计参数的映射,建立公理设计矩阵;分析各设计参数之间及其与功能要求之间的敏感性,构建设计关联矩阵并对其进行关联度分析;然后通过变型产品关于设计参数的差异度计算,合理识别平台参数和变型参数,确定设计参数在产品平台中的共享策略．通过桥式起重机产品族的柔性配置实例,证明了该方法的可行性和实用性．     

Joint effects of remanufacturing channel design and after-sales service pricing: an analytical study

We conduct an analytical study on remanufacturing channel design and after-sales service pricing, which jointly affect the sustainability and profitability of the supply chain. We model a supply chain with one manufacturer and one independent retailer. The manufacturer, as the Stackelberg game leader, engages in remanufacturing to take advantage of production cost savings. The collection of the used products can be carried out by either the manufacturer or the retailer. After-sales service, for example, extended warranty, is offered with the product and is sold separately. The service provider can be either the manufacturer or the retailer. We use game theoretic models to answer an important research question: How do remanufacturing and after-sales service jointly affect channel selection decisions? We explore the benefits of joint decision making in terms of remanufacturing efficiency and after-sales service performance. We find that it is most efficient for the retailer to collect the used product for remanufacturing and to offer after-sales service, because the retailer simultaneously makes decisions regarding remanufacturing and after-sales service and thus reduces double marginalisation in the supply chain. We also demonstrate numerically how the costs of collecting used products and providing after-sales service impact channel selection decisions.     

Design for life-cycle profit with simultaneous consideration of initial manufacturing and end-of-life remanufacturing

Remanufacturing is emerging as a promising solution for achieving green, profitable businesses. This article considers a manufacturer that produces new products and also remanufactured versions of the new products that become available at the end of their life cycle. For such a manufacturer, design decisions at the initial design stage determine both the current profit from manufacturing and future profit from remanufacturing. To maximize the total profit, design decisions must carefully consider both ends of product life cycle, i.e. manufacturing and end-of-life stages. This article proposes a decision-support model for the life-cycle design using mixed-integer nonlinear programming. With an aim to maximize the total life-cycle profit, the proposed model searches for an (at least locally) optimal product design (i.e. design specifications and the selling price) for the new and remanufactured products. It optimizes both the initial design and design upgrades at the end-of-life stage and also provides corresponding production strategies, including production quantities and take-back rate. The model is extended to a multi-objective model that maximizes both economic profit and environmental-impact saving. To illustrate, the developed model is demonstrated with an example of a desktop computer.     

The effect of risk aversion on product family design under uncertain consumer segments

A product family refers to a group of products that have been derived from a common product platform and which are specifically designed to satisfy a variety of market segments. In this paper, we consider a firm utilising product family design in order to respond to the requirements of two consumer segments, each characterised by different quality valuations. Although the total number of consumers in the market is known, the proportions each segment share are random, with known mean and variance. We show how the uncertainty of the market segmentation affects the firm's decision whether to use common rather than unique components. Motivated by a problem faced by a major automotive manufacturer, we study the consequence of low and high uncertainty, various product quality levels and the difference of marginal valuation on the best configuration.     

产品语意学在设计中的应用

通过讨论产品语意学在设计中的应用,使设计师更准确地把用户的社会属性映射在产品形态上,开发出受市场欢迎的产品,从而透视出产品语意是产品创新设计源泉的观点.     

产品包装的人性化设计

产品和产品包装是不可分割的整体,在进行产品包装设计的时候,就要充分的考虑人的因素,不仅仅要考虑包装的基本功能,还要有很多和产品相关的人性化考虑.比如在包装给人的信息方面和使用方面,多站在使用者的角度来考虑.     

Simultaneous design of a product family and its related supply chain using a Tabu Search algorithm

Product family design is currently facing a multitude of challenges, the main problem stemming from the diversity offered to consumers. To design a product family, designers have to define an efficient bill of materials which ensures product assembly within a predefined length of time in order to satisfy the synchronised delivery principle. In addition, the modules used to assemble the finished products have to be competitive in terms of logistical costs. The ability to anticipate the constraints associated with the production process and with transportation is consequently of great interest. In this paper, we focus on the process of identifying a set of modules to be used in the assembly of the finished product. The objective is to define the bill of materials for each product from the modules belonging to that set, and to assign these modules to distant facilities where they will be manufactured and then shipped to a nearby facility for final assembly within a specific time. We use a set partitioning formulations to represent the problem, and solve it by adapting a Tabu Search algorithm in which the assembly process and the supply chain design are considered at the same time.     

基于联合分析和模糊聚类的产品族客户需求模型研究

客户需求信息的准确获取与表达是产品族规划的首要环节,针对客户需求模型构建过程中需求信息具有抽象性、模糊性等特点,基于公理设计构建描述客户需求的模型,运用联合分析法对客户需求进行量化,将模糊的客户需求转换为具体的产品设计指标和参数.通过对指标和参数的相关性分析,建立产品设计关联矩阵.采用模糊最大树聚类算法对设计关联矩阵进行聚类分析,以聚类有效性指标为依据,得到最佳聚类阈值,从而获得最优聚类结果.在此基础上,利用最优聚类结果对设计关联矩阵进行解耦,最终得到解耦设计关联矩阵,为参数化产品族规划提供理论依据.最后,以圆柱齿轮减速器产品族规划为实例,验证了该方法的有效性和可行性.     

Joint hybrid repair and remanufacturing systems and supply control

The control of a stochastic manufacturing system that executes capital asset repairs and remanufacturing in an integrated system is examined. The remanufacturing resources respond to planned returns of worn-out equipment at the end of their expected life and unplanned returns triggered by major equipment failures. Remanufacturing operations for planned demand can be executed at different rates and costs corresponding to different replacement and repair modes. The replacement components inventory is provided by an upstream supply with random lead times. The objective is to determine a control policy for both the supply and remanufacturing activities that minimises the average repair/replacement, acquisition and inventory/shortage total cost over an infinite horizon. We propose a suboptimal joint remanufacturing and supply control policy, composed of a multi-hedging point policy (MHPP) for the remanufacturing stage and an (s, Q) policy for the replacement parts supply. The MHPP is based on two inventory thresholds that trigger the use of predefined remanufacturing modes. Control policy parameters are obtained combining analytical modelling, simulation experiments and response surface methodology. The effects of the distribution, mean and variability of the lead time are tested and a sensitivity analysis of cost parameters is conducted to validate the proposed control policy. We also show that our policy leads to a significant cost reduction as compared to a combination of a hedging point policy (HPP) and an (s, Q) policy.     

Development of a production cost estimation framework to support product family design

The main task of a product family designer is to decide the right components/design variables to share among products to maintain economies of scale with minimum sacrifice in the performance of each product in the family. The decisions are usually based on several criteria, but production cost is of primary concern. Estimating the production cost of a family of products involves both estimating the production cost of each product in the family and the costs incurred by common and variant components/design variables in the family. To estimate these costs consistently and accurately, we propose a production cost estimation framework to support product family design based on activity-based costing (ABC), which consists of three stages: (1) allocation, (2) estimation, and (3) analysis. In the allocation stage, the production activities and resources needed to produce the entire products in a family are identified and classified with an activity table, a resource table, and a production flow. To help allocate product data for production, a product family structure is represented by a hierarchical classification of products that form the product family. In the estimation stage, production costs are estimated with cost estimation methods selected based on the type of information available. In the analysis stage, components/design variables possible for product family design are investigated with resource sharing methods through activity analysis. As an example, the proposed framework is applied to estimate the production cost of a family of cordless power screwdrivers that share different components within the family.     

儿童产品的人性化设计

研究了儿童的特点及分析儿童产品的现状,论述了对儿童产品进行人性化设计的必要性.在人性化设计理念的基础上,提出了对儿童产品的人性化设计原则;同时通过具体的实例论证人性化设计原则在儿童产品设计中的重要性.     

现代产品设计中的适当设计理念

论证了在现代产品设计中提出适当设计理念的理由,阐述了适当设计的本质含义.并从消费需求、产品的功能、材料及造型等4个方面,对适当设计的具体运作方法进行了比较详细的分析和研究.同时也指出了,利用适当设计,可使产品能最准确地满足目标群体最真实、最合理的消费需求,以缓解当前因产品的过度设计所带来种种问题.