【作者】 张以彬；

【导师】 陈俊芳；

【作者基本信息】 上海交通大学 ， 企业管理， 2008， 博士

【摘要】 作为全球经济发展和繁荣的一种主要驱动力量,技术创新正在使企业运营的环境变得越来越复杂和不确定。一方面,由于创新速度的加快缩短了产品在市场上的存续时间,产品的生命周期被不断地压缩。为了求得生存和可持续发展,很多厂商被迫加快技术创新的速度,不断地推出创新产品和改进生产工艺。创新产品,如高科技产品和时尚品,因具有高利润边际,日益成为各个厂商获取利润的业务增长点。另一方面,由于具有短的生命周期、需求和供应的高度不确定,很多厂商在投放这些创新产品时通常会面对产能或库存方面的风险暴露问题,给管理其供应链提出新的挑战。例如,当市场需求攀升时,会出现产能不足而损失销售的供应风险;当市场需求下跌时,在售季节末期因库存过剩而出现产品降价或报废的库存风险等等。这些现象严重影响了创新产品的供应链绩效。因此,如何以一种响应的和有效的方式来生产和交付创新产品给客户,分摊或规避有关库存风险,改进供应链绩效,成为本文关注和研究的主要问题。针对创新产品,国外研究多关注概念形式的描述、相关供应链战略设计的定性分析,以及需求预测Bayesian更新和非平稳需求过程的定量研究;而国内对创新产品具有针对性的研究则很少。现有的定性研究缺乏一种创新产品供应链战略设计的总体框架和应对需求不确定性的可行措施,以及在效率和响应速度之间权衡的分析;定量分析又显得过于复杂而缺乏可操作性。这些理论上的不足制约了创新产品的生产和交付,必须深入研究并提出可行的理论指导方法。柔性作为一种机制,能使厂商在面对不确定性时具有匹配产品的需求和供应、并促进厂商快速响应客户的定制要求的能力,对创新产品尤为重要。本文把柔性纳入创新产品的供应链设计和协调之中,提出一种供应柔性的框架模型。这种供应柔性由战略层上重构供应链的柔性和战术层上的产能柔性与提前期柔性组成,构成全文的总体研究架构。目的在于,通过随产品生命周期变化来重构创新产品供应链,以改进创新产品的供应链绩效;通过在创新产品供应链中建立产能柔性和提前期柔性来充当不确定性的缓冲机制,以便分摊或规避相关库存风险。相关研究过程运用优化理论、合同论、博弈论和实物期权方法等多种学科的理论方法进行定性和定量分析,最终得到一些有益的和具有创造性的结论。主要工作成果及结论如下:(1)研究创新产品的供应链战略设计问题。根据产品生命周期的长短、需求特性和市场要求的响应性的差别,把创新产品细分为技术创新产品和时尚创新产品。不同的产品要求的供应链战略是不同的;在不同的产品生命周期上,供应链战略也会发生变化。这需要在产品生命周期上不断地调整供应链战略,通过解藕点的战略定位来获得一定的供应柔性。研究发现,在创新产品供应链中,这种供应柔性能使创新产品不确定的供应和需求相匹配,并改进供应链绩效,是成功投放创新产品的关键。(2)通过一种非线性优化模型,对创新产品供应链中解耦点的战略定位进行优化。解耦点,作为实时需求向供应链上游的渗透点,将创新产品供应链分成精益供应和敏捷供应两部分,并通过在该点的战略库存来平衡整个供应链的生产率和柔性。各阶段的总成本由库存持有成本、短缺订货成本和生产系统的运营成本组成。在客户服务水平约束下,将个总成本作为目标函数进行优化。研究发现,最优的解耦点和战略库存缓冲的规模随服务水平的降低而递减,随需求平均到达率的增加而递增。(3)通过一个稳健混合整数规划模型,对创新产品的生产和配送的战略规划进行优化。产品的生产和配送的战略规划是投放创新产品时必须考虑的供应链设计问题。由于创新产品的需求和成本等的不确定性,有关决策参数的选择会受到严重干扰。提出一种稳健优化模型,考虑创新产品的生产和配送的两个阶段,目标函数由工厂的生产固定成本和可变成本、工厂到配送中心的运输成本、配送中心的库存持有成本和固定运营成本以及从配送中心到客户的运输成本组成。选择每种情景的相对稳健性测度作为惩罚项纳入目标函数中,以便对每种情景所发生的概率进行加权,确保模型的解不被一种可能性极少的情况所驱动。研究发现,模型对创新产品的需求不确定性是稳健的,能使创新产品的生产和配送规划获得一定的柔性。(4)研究在合同制造的环境下通过实物期权来设计定制件采购中有产能柔性和提前期柔性的协调机制。用产能柔性和提前期柔性来代替传统的库存缓冲方法,充当一种吸收需求不确定性的缓冲机制,使创新产品供应链从战术上获得供应柔性。(5)为合同制造中定制件的采购设计了一种有产能柔性的预订合同协调机制。在合同制造的环境下,由于数量柔性合同只有在供应商具有产能柔性时才能充当需求不确定性的缓冲机制,供应商和采购商之间有必要通过谈判来签订一份产能柔性预订合同,以便应对在创新产品的需求攀升时出现的定制件采购短缺或报废现象。一种基于实物期权的产能预订模型提供一种Stackelberg博弈机会,供应商决定最优的产能期权价格,而采购商优化产能柔性预订的数量。研究发现,因为期权合同的柔性,采购商的有关需求不确定性导致的定制件库存风险可以通过产能期权部分转给供应商,供应商建立柔性产能来消化这种库存风险,并从产能期权中获得的额外收益补偿。这种合同机制能应对创新产品的需求不确定性和分摊或规避定制件采购的库存风险。(6)为创新产品的零部件采购决策设计了一种有交付提前期柔性的合同协调机制。在合同制造的环境下,由于减少供应商的补给提前期及其变动幅度可以减少库存而不伤害所提供的服务水平,建立一种有关交付提前期柔性的期权机制,可以实现供应链中的零部件库存的风险分摊。采购商在确定一个产品的交付提前期后,在执行之前观察到需求发生变化,把交付到期日修改到比原定时间提前或延缓。显然,这种谈判机制是关于提前期的实物期权。采购商通过承担一定比例的提前期柔性成本来换取供应商执行提前期柔性的期权,以便响应需求不确定性并分摊有关分零部件的库存风险。研究发现,这种关于提前期柔性的Stackelberg博弈能使供应链双方通过合理选择提前期柔性成本的分摊比例来最大化各自的利润、分摊零部件的库存风险,并获得渠道最优的纳什均衡解。本文的主要创新:(1)提出在创新产品供应链中通过精益供应和敏捷供应之间解耦点的战略定位来权衡供应链的效率和响应性,以改进其供应链绩效。在方法上,M/M/1排队理论和有限位相型分布被用来近似测度相关指标,并利用遗传算法来求解非线性优化问题。(2)把相对稳健性作为一种松弛变量纳入到创新产品供应链的稳健优化模型中。在需求出现极端或最坏情况下,通过稳健优化,得到创新产品的生产和配送规划中的相关决策变量的稳健解。(3)将实物期权的理论思想和方法引入到创新产品供应链的定制件采购的合同机制设计中,并提出用产能柔性代替传统的库存缓冲,以应对创新产品的需求不确定性和分摊或规避定制件采购的库存风险。(4)把对交付提前期的加快或延缓看成一种实物期权,建立了有交付提前期柔性的创新产品的定制件采购合同的协调机制,用以代替传统的库存来充当对创新产品的需求不确定性的缓冲机制。应该指出的是,在解耦点优化模型中,当各阶段的利用率不相同时,对解耦点的优化比较复杂,求解可能存在一定的难度,这点成为本文的局限性。另外,一般来说,创新程度越高,要求的供应柔性越大,以便缩短响应时间,但增加柔性会增加成本,所以,提前期柔性机制的应用是有条件的。创新产品的供应柔性模型对厂商的新产品开发、供应网络的布局优化和投放新产品具有指导作用,并提供一些管理见识。更多还原

【Abstract】 As one of the key drivers for global economic development and boom, technological innovation is creating a more knowledge-intensive, complex and uncertain environment. The increasing rate of innovation shortens each product’s duration in the market, thereby compressing each product’s life cycle, facilitating product proliferation. In order to survive in this competitive environment and keep sustained competitive advantage, many companies are forcing to increase their rates of innovation by developing and introducing innovative products and improving their process technology. Innovative products, such as hi-tech products and style items, are increasingly becoming the focus on enhancing profitability by many companies. On the other hand, owing to short life cycle and high uncertainty of supply and demand, many companies will have to confront with some risks exposure to capacity or inventory issue when they launch an innovative product to market. This challenges to the supply chain management to innovative products. For example, when market demand is ramp-up or downside, large variability of demand continues to result in some supply risk for production capacity shortage and penalty to lose some sales or some inventory risks for markdown or obsolescence. All these risks badly affect on its supply chain performance. So how to produce and delivery innovative products to customer in a responsive and cost-efficient way become the research topic and focus in this dissertation.Some oversea studys on innovative products are limited to qualitative description on its concept and relevant SC strategic design and quantitative analysis on Bayesian updating of demand forecast and non-stable demand process. It’s seldom discussed by domestic researchers. All of these studys lack of a overall framework on on innovative products supply chain design and feasible measurement against demand uncertainty. Some quantitative analysis is too complex to have maneuverability. Those limitations restrict the production and delivery of innovative products and some feasible theory and method should be proposed.Flexibility is a mechanism that enables firms to match their products’supply to market demand in the face of uncertainty because it facilitates a quick response and provides the ability for firm to provide niche and customized products to the consumer. This is especially important in the provision of innovative products. Therefore, to meet customer needs, flexibility must be built into its supply chains design and coordination to hedge against the demand uncertainty, so as to build up an overall concept framework on supply flexibility for this dissertation. Moreover, supply flexibility contained the flexibility to re-configurate supply chain strategically and the capacity flexibility and leadtime flexibility tactically. The purpose of this research target that supply flexibility is captured to improve supply chain performance for innovative products through re-configurating this chain and to share or to hedge the inventory risks tactically through using capacity flexibility and leadtime flexibility to act as a buffer mechanism to demand uncertainty. Some theories such as optimization, contract theory, game theory and real option were used to model and analyze the relevant problems qualitatively and quantitatively. Some originative results are deduced as follow:Firstly, supply chain design on innovative products was discussed at the strategic level. Innovative products can be categorized into technological innovative products and fashion innovative products according to their life cycle length, demand characteristic and required responsiveness. The different products require different supply chain strategy. On different stages of product life cycle, the required supply chain strategy may also change. It is necessary to built up supply flexibility by the strategic positioning of decoupling point in an innovative products supply chain and adjusting or reconfigurating supply chain strategy on the product life cycle. It was found that it is key important to succeed in launching innovative products by building supply flexibility in an innovative products supply chain and match uncertain demand with uncertain supply and affect on a company competitive strategy. Secondly, the strategic positioning of decoupling point in an innovative products supply chain was optimized by a non-linear optimaztion model. one of the methods to acquire supply flexibility strategically is the selection and optimization of strategic positioning of decoupling point in an innovative products supply chain. Decoupling point, defined as a point for real demand to penetrate to upstream along supply chain, separate innovative products supply chain into two parts of lean supply and agile supply. The tradeoff between production and flexibility in the whole chain is required by the strategic inventory at this point. An optimization model on the strategic positioning of decoupling point was used to minimize the objective founction under the constraint of customer’s service level. This founction is the total cost for each stage, which is made up of inventory holding cost, shortage backorder cost and operation cost of production system. It was found that optimal decoupling points and optimal buffer size are decreasing in service level, increasing in average demand arrival rate.Thirdly, the roubust optimization for the palnnig of production and distribution of innovative products was taken by a roubust mix integer programming model. It should be considered when lunching innovative products. A robust mix integer programming model involves in production and distribution two stages. Its objective function concludes the fixed cost and variable cost, the transportation cost from factory to DC, the inventory holding cost and fixed operation cost in DC, and the transportation cost from DC to customer regime. Relative robustness measurement is selected as penalty term for various scenarios and incorporated in the objective function. Using the weighted average ensures that the model solution is not driven by one remote case. It was found that the model is robust to demand uncertainty for innovative products.Fourthly, two coordination mechanisms ware designed through build capacity flexibility and leadtime flexibility into customized components purchase by real option in contract manufacturing. Rather than using traditional inventory as a buffer, capacity flexibility and leadtime flexibility are acted as a buffer mechanism to absorb demand uncertainty and provide some supply flexibility for innovative products supply chain at the tactical level.Fifthly, capacity flexibility, built in contract on real option between supplier and buyer, may be used to deal with innovative products’demand uncertainty and share in the inventory risks. In the environment of contract manufacturing, quantity flexibility contract is not significant until suppler have flexible capacity and used as a buffer mechanism to demand uncertainty. Thus, it is necessary for buyer and supplier to sign flexible capacity reservation contract through negotiation, so as to deal with supply shortage or obsolescence phenomena occurring in the purchase of customized components when innovative products’demand is ramping up. So a real-option-based flexible capacity reservation model provide an opportunity for supplier select optimal capacity option pricing and buyer determine their optimal capacity reservation through Stackelberg game. It was found that component inventory risks resulted from demand uncertainty may be transferred to supplier due to the flexibility of option contract. In return, supplier may build up its flexible capacity to counter against these inventory risks and be compensated from this capacity option to hedge against the demand uncertainty and risks.Sixthly, delivery leadtime flexibility, built in contract on real option between supplier and buyer, may also be used to deal with innovative products’demand uncertainty and share in the inventory risks. In the environment of contract manufacturing, since reduction of supplier replenishment leadtime and the variety of leadtime may reduce inventory without harming provided service level, a option mechanism on leadtime flexibility was built up to share the component inventory risk in innovative products supply chain. After determining a component delivery due-date but before execution, buyer observed demand changing and want to modify the delivery leadtime to expedite or postpone. Apparently, this negotiate mechanism is a real option on leadtime. Buyer burdens a proportional of cost to build leadtime flexibility and encourages supplier execute option on leadtime so that response to demand uncertainty and share the risks of component inventory. It was found that this Stackelberg game negotiation on leadtime flexibility may enable buyer to order the optimal quantity and channel to obtain a Nash equilibrium solution through reasonable sharing proportional of leadtime flexibility cost.Some originalities in this dissertation:(1)It was proposed that efficiency and responsiveness of innovative products SC should be tradeoffed by the strategic positioning of decoupling points between lean supply and agile supply so as to improve SC performance. M/M/1 queue theory and PH-distribution approximate arithmetic were taken to mesure some parameters. The non-linear optimaztion was resolved by Genic Arithmetic.(2)The definition of relative robustness was taken as Lagrangian slack variable to incorporate in the robust model for an innovative product supply chain. Some decision variables on strategic production and distribution planning are optimized under the extreme case of demand or the worst condition and robust solutions are achieved.(3)Real option was incorporated in the purchase decision of customized component of innovative products and a decision model was proposed for flexible capacity reservation contract. This model can better the condition for buyer to deal with demand uncertainty of innovative products and shareing or hedging the relevant inventory risks of customized component.(4)A real-option-based model on leadtime flexibility presents another supply flexibility of component purchase decision. This flexibility may replace partial inventory so as to deal with the demand uncertainty. if the sharing proportion of leadtime flexibility cost is determined reasonably through bargaining negotiation, some inventory may be hedged and buyer’s order quantity will be optimal and channel acquire coordination.In the optimization model of decoupling points, when there are different utilization rates, to resolve the optimal solution of decoupling points may be complicated. This is the limitation of this dissertation.The model of supply flexibility for innovative products may provide some guide and management insight in new product development, supply network configuration, introducing and launching new product.更多还原