Supplier selection-order allocation: A two-stage multiple criteria dynamic programming approach

This paper proposes a two-stage multiple criteria dynamic programming approach for two of the most critical tasks in supply chain management, namely, supplier selection and order allocation. In the first stage, to address multiple decision criteria in supplier ranking, the analytic hierarchy process (AHP) is employed. In the second stage, supplier ranks are fed into an order allocation model that aims at maximizing a utility function for the firm as well as minimizing the total supply chain costs, subject to constraints on demand, capacity, and inventory levels. A dynamic programming approach is crafted to solve the proposed bi-objective model.     

A weighted max-min model for fuzzy multi-objective supplier selection in a supply chain

Supplier selection is one of the most important activities of purchasing departments. This importance is increased even more by new strategies in a supply chain. Supplier selection is a multi-criteria decision making problem in which criteria have different relative importance. In practice, for supplier selection problems, many input information are not known precisely. The fuzzy set theories can be employed due to the presence of vagueness and imprecision of information. A weighted max-min fuzzy model is developed to handle effectively the vagueness of input data and different weights of criteria in this problem. Due to this model, the achievement level of objective functions matches the relative importance of the objective functions. In this paper, an analytic hierarchy process (AHP) is used to determine the weights of criteria. The proposed model can help the decision maker (DM) to find out the appropriate order to each supplier, and allows the purchasing manager(s) to manage supply chain performance on cost, quality and service. The model is explained by an illustrative example.     

基于改进TOPSIS法的供应商选择模型研究

为有效地帮助企业快速找到合适的供应商合作伙伴,采用直觉模糊集、评分函数等方法对TOPSIS评估法进行优化,并以此为基础建立了一种供应商选择模型。首先,采集和评估供应商的产品质量、产品价格、产品交货的可靠性、供应位置、财务情况、库存水平、劳资关系、发展能力和技术能力等相关信息,由专家给出主观评估信息,汇总为综合属性值;然后,通过直觉模糊熵确定各评估指标的权重;最后,综合考虑供应商选择决策过程中的多个目标和标准,应用改进TOPSIS法的对供应商进行分类选择。结果显示,基于改进TOPSIS法的供应商选择模型能够较准确地反映出各供应商的真实水平和对企业的潜在价值,可以有效地解决不确定条件下对供应商的选择问题,提高了供应商选择结果的可靠性。改进后的模型简便易行,具有良好的稳定性,对于合理制定企业供应商选择标准以及进一步优化决策模型具有一定的借鉴意义。     

Competitive pricing decisions in a two-echelon supply chain with horizontal and vertical competition

This study investigates the pricing decisions in a non-cooperative supply chain that consists of two retailers and one common supplier. The retailers order from the common supplier and compete in the same market. We analyze six power structures that characterize exclusively horizontal competition between the retailers and vertical competition between the supplier and the retailers, leading to different sequences of moves among the chain members. We derive the analytical forms of the equilibrium quantities under each power structure and explore the effect of retail substitutability on the equilibrium quantities among all power structures. We further investigate the performances of the game models as compared with the integrated model.     

Supply contract with options

The purpose of this paper is to analyze the impact of an option contract for two companies of a supply chain: retailer and supplier. With an option contract the retailer orders a quantity of units and has the right to modify his order if necessary. A model to calculate the performance of an option contract in terms of contract value for the two companies engaged is presented. The two considered cases are multiple suppliers and one retailer, and one supplier and one retailer. The performance improvement obtained using this kind of contract is compared by simulation.     

The role of trust and relationship structure in improving supply chain responsiveness

In order to reduce cycle times between supply chain entities, managers must work to create new relational forms that rely on trust to a greater extent. We present a model suggesting that to build relationships based on trust, suppliers must invest in site-specific and human assets, and buyers must judiciously apply contracts to control for relative levels of dependence within the relationship. Our model also suggests that buyer-dependence, supplier human asset investments, and trust are all positively associated with improved supply chain responsiveness, defined in this study as the supplier's ability to quickly respond to the buying party's needs. This model is tested with data gathered from a sample of purchasing managers in North American manufacturing firms. The results suggest that even in cases when buyers do not have a great deal of control over their suppliers, working to build trust within the relationship can improve supplier responsiveness.     

Enhancing the business-to-business supply chain: Insights from partitioning the supply-side

A market orientation has long been established as the key to success in supply chain management. A central concept of this orientation is market segmentation. The concept of market segmentation, however, has primarily been focused on the demand side of the supply chain; its potential application on the supply side has not thoroughly been addressed. This paper extends the purview of the concept behind segmentation by presenting the concept of “supply-side partitioning” to refer to the management of heterogeneities on the supplier side of the supply chain. Further, the concept of “transvectional alignment” is proposed for the purpose of simultaneously aligning market segments with appropriate suppliers at all levels of the supply chain by identifying, evaluating, and selecting supply groups that satisfy the demand function(s) of each segment. This paper discusses supply-side partitioning, includes a model for the supply chain utilizing transvectional alignment, and offers implications for the application of supply-side partitioning in the business-to-business marketspace.     

Product quality selection: Contractual agreements and supplier competition in an assemble-to-order environment

We consider a multi-supplier, single-manufacturer supply chain where each supplier sells a different component at varying quality levels. The manufacturer has to decide on which quality level to choose for each component, trading-off the total cost and total quality. Each supplier decides on a price per unit quality level for its component. We characterize the strategic interaction among the suppliers and analyze the inefficiencies. We find that the inefficiencies due to such quality competition can be quite significant. We then propose and analyze several mechanisms, such as quality-price schedules and revenue sharing, that restore efficiency.     

The role of supplier performance evaluations in mitigating risk: Assessing evaluation processes and behaviors

Given the level of outsourcing, supplier performance evaluation (SPE) is a critical supply chain process. SPEs are used to record supplier performance levels to inform future supplier selections, and thus mitigate the risk of adverse selection. Numerous weaknesses associated with industrial buyers' collection and use of supplier performance information call SPE effectiveness into question. The risk-related factors affecting SPE effectiveness have not been empirically explored, including misuses of the tool. This research identifies the factors affecting SPE risk mitigation effectiveness. It employs a mixed method of qualitative interviews of buyers and suppliers in order to develop a model of SPE risk mitigation effectiveness using structural equations modeling of survey data from a rare sample of 131 performance assessors. Findings implicate the importance of a thoroughly defined scope of work, an accurate SPE, and documented rating justifications. Additionally, dissonance among several performance evaluators and the fear of a supplier's dispute detract from SPE risk mitigation effectiveness. Finally, this research unveils how SPEs are weaponized, pursuing short-term gains and clouding the view of the supplier's performance thereby hindering the long-term, risk-mitigating purpose of SPEs. Two separate forms of opportunism - threat and debt - are discovered and have differing effects.     

System supplier's customer strategy

The article addresses the management of dynamic customer relationships in large-scale, complex system business. It combines the existing knowledge on system business, high-tech services and buyer-seller relationships with an international multiple case study. As a result, we produce a framework model, which provides the answers to the following critical questions: What are the key activities through which a system supplier provides value for the customer? What are the system supplier's roles for the customer? How does the customer's strategy and capabilities influence the customer's need for the supplier's activities and its evaluation of potential suppliers? And, how does the stage of the supplier-customer relationship and the system's technology cycle influence the customer's perceived need for the supplier's activities? In sum, the framework model provides a major theoretical contribution to more profoundly understand and manage complex system supplier-customer relationships.     

Supply chain scheduling and coordination with dual delivery modes and inventory storage cost

We study a two-echelon supply chain scheduling problem in which a manufacturer acquires supplies from an upstream supplier and processes orders from the downstream retailers. The supply chain sells a single short-life product in a single season. We consider the scenario where the manufacturer can only accept some of the orders from the retailers due to its supplier's common production time window and its own two common production and delivery time windows. The upstream supplier processes materials and delivers the semi-finished products to the manufacturer within its time window. Then the manufacturer further processes these products to produce finished products and delivers them to the retailers within its two time windows, where one window is for production and normal delivery, and the other is for production and express delivery. Having to store the materials before processing them, the supplier incurs a storage cost, which depends on the order size and storage time. The manufacturer pays the transportation cost for delivering the finished products to the retailers. Due to double marginalization, the performance of the supply chain is sub-optimal. We model the supply chain problem as a flow shop scheduling problem with multiple common time windows. We derive some dominance properties and establish some theorems that help solve the sequencing problems for the orders and eliminate the idle time among the orders. Based on these results, we develop fast pseudo-polynomial dynamic algorithms to optimally solve the problem. We prove that the problem is NP-hard in the ordinary sense only. We develop two practically relevant and robust methods for the supply chain to achieve optimal profit-making performance through channel coordination.     

Supply chain risk, simulation, and vendor selection

This paper considers three types of risk evaluation models within supply chains: chance constrained programming (CCP), data envelopment analysis (DEA), and multi-objective programming (MOP) models. Various risks are modeled in the form of probability and simulation of specific probability distribution in risk-embedded attributes is conducted in these three types of risk evaluation models. We model a supply chain consisting of three levels and use simulated data with representative distributions. Results from three models as well as simulation models are compared and analysis is conducted. The results show that the proposed approach allows decision makers to perform trade-off analysis among expected costs, quality acceptance levels, and on-time delivery distributions. It also provides alternative tools to evaluate and improve supplier selection decisions in an uncertain supply chain environment.     

基于收益共享的供应链中断协调研究

本文假定市场需求不确定和供给存在中断危机，同时考虑订货过剩损失和缺货成本，研究了由零售商、主供应商和备份供应商组成的供应链网络，构建了收益共享合同协调模型，通过相关参数的设定达到供应链协调。供应链协调时的供货量及整体利润均大于分散模型；备份供应商的供货量及利润随着中断危机的增大而增加，零售商利润也随之增加。     

零售商的风险规避特性和公平偏好对绿色供应链运作的影响

针对市场需求的不确定性,本文通过建立风险规避型零售商与风险中性供应商的Stackelberg博弈模型,供应商为主导者,综合考虑零售商风险规避特性和公平偏好心理对该供应链运作产生的影响。研究发现,当风险规避型零售商不具有公平意识时,零售商的风险规避程度与供应商的批发价、绿色创新投入水平以及供应商和供应链整体的效用正相关;供应商的绿色成本系数的大小可影响风险规避程度对产品售价以及零售商效用的影响。当风险规避型零售商具有公平偏好时,零售商的公平偏好负向影响产品售价、批发价以及供应商绿色投入水平和供应商效用;零售商公平偏好对零售商以及供应链效用产生的影响受到零售商风险规避程度的影响。     

Suppliers capability and price analysis chart

To remain competitive in customer-oriented economics, the major parties in the supply chain should be integrated and managed effectively to respond to customer needs. Thus, the efficiency of the entire supply chain is a main concern, and is determined by the members of that supply chain. Partner selection thus becomes one of the key steps in supply chain construction. Given buyer–supplier information asymmetry, obtaining complete information from suppliers is difficult, since some supplier attributes cannot be definitely and quantitatively measured. This study establishes a suppliers capability and price analysis chart (SCPAC) focused on the case where the specification limits are symmetric about the target for evaluating supplier performance which applies the process incapability index C_pp introduced by Greenwich and Jahr-Schaffrath (International Journal of Quality & Reliability Management 12 (1995) 58) to measure supplier quality performance and the price index I_p is proposed here to display the difference between budget and component price. Practitioners can instantly and visually obtain information based on the locations of suppliers and price indices on SCPAC. SCPAC also provides clear directions for quality improvement, such as process accuracy and precision. SCPAC thus is an effective and efficient method for evaluating suppliers, which can simplify supplier evaluation, facilitate their effective visual selection, and provide insights into the process situation of suppliers who can become technological innovation partners.     

A JIT lot-splitting model for supply chain management: Enhancing buyer–supplier linkage

This study develops a buyer–supplier coordination model to facilitate frequent deliveries in small lot sizes in a manufacturing supply chain. The proposed model, based on the integrated total relevant costs of both buyer and supplier, determines optimal order quantity, the number of deliveries/setups, and shipping quantity over a finite planning horizon in a relatively simple JIT single buyer single supplier scenario. Under deterministic conditions for a single product, we show that the optimal delivery policy adopted by both buyer and supplier in a cooperative manner can be economically beneficial to both parties. It is shown that the optimal delivery size can be unique, regardless of the order quantity and the number of deliveries. Numerical results are also presented.     

供应链上制造商与供应商关系的影响因素探讨——基于以制造商为核心的视角

当今社会的市场竞争已经转变为供应链之间的竞争,供应链上节点企业之间关系的好坏已经对供应链竞争力的强弱产生重要影响。制造商与供应商的关系是供应链成员关系的重要组成部分,文章对其关系的类型进行了划分,并在此基础上分析了其关系好坏的取决于合作中的供给产品、技术能力和人为因素等多方面的作用,明确了在每一方面又存在多种影响因素,且不同影响因素的作用存在着差异,这些诸多因素的综合作用决定了供应链上制造商与供应商的关系,最终决定了供应链运行的好坏。     

基于利他行为下的闭环供应链决策研究

随着行为运营管理的发展,利他、公平、信任等行为得到广泛的关注。文章构建一个由供应商和零售商的闭环供应链,供应商负责旧产品回收再加工。将利他行为引入到供应链中,研究利他属性对供应链决策的影响。研究发现,在该模型的供应链中,供应商的利他属性,对于供应链的回收率、零售商的利润、供应商的效用、供应链的整体利润都是有益的。而零售商的利他行为,有利也有弊,带来的效益是局部的。然后通过数值分析对结论作出解释和说明。     

政府补贴下的三级低碳供应链减排博弈研究

本文分别构建了政府补贴下,供应链上企业单独减排、供应商对制造商碳减排成本进行分担、供应商和零售商均对制造商碳减排成本进行分担3种减排模型,求解得到不同减排模式下,包括成本分担率和单位减排量在内的供应链最优决策。研究发现,政府补贴率的提升反而使成本分担率降低。通过博弈分析及算例验证得出：在供应链上三方企业联合减排下,即供应商和零售商都对制造商的碳减排研发提供资金支持时,单位产品的减排量及各企业利润达到最大,仅供应商对制造商碳减排成本分担时次之, 供应链上企业单独减排时最小, 但仅供应商一方对制造商的碳减排成本进行分担时的成本分担率,比其与零售商同时分担时的要大。这些结论为政府确立合适的补贴方案及供应链上企业减排策略的制定提供了理论依据。     

Strategic cost management across boundaries of firms

In recent years, increasing attention has been placed on how purchasing strategies may contribute to the efficiency of firms. In this paper, a case study illustrates how one firm implemented a supplier base reduction to enable a high involvement strategy in relation to appointed key suppliers. The effects of this change in purchasing strategy were extensive cost rationalisations. The main change in this process was a redefinition of the unit of analysis from individual transactions to buyer-supplier relationships. However, the costs in the relationship are driven not only by internal factors on the two sides of the relationship but also by how the focal relationship relates to other relationships. Therefore, the ways in which the costs are affected by other parties, such as the supplier's supplier, the supplier's other customers, the customer's other suppliers, and the customer's customers, need to be included in the analysis.