On E‐Auctions for Procurement Operations

Electronic auctions have revolutionized procurement in the last decade. In many situations, they have replaced negotiations for supplier selection and price setting. While they have often greatly reduced transaction costs and increased competition, they have also encountered problems and resistance from suppliers resenting their intrusion on cooperative supplier/buyer relationships. In response to these issues, procurement auctions have evolved in radical new directions. Buyers use business rules to limit adverse changes. Some procurement auctions allow bidders to offer variants in the specifications of products to be supplied. Most important, some suppliers are allowing bidders to bid on packages of items, not just individual items. This tends to change procurement auctions from zero‐sum fights over supplier profit margins to win‐win searches for synergies. These changes have opened up many new research areas. Researchers are trying to improve how to deal with the computational issues involved in package auctions and to analyze the new auctions forms that are evolving. In general, equilibrium incentives are not known, and dealing with ties in package auctions is an issue. Computer scientists are analyzing the use of computerized bidding agents. Mechanisms that combine auctions with fixed buy prices or with negotiations need to be analyzed.     

Introduction to the Special Issue on E‐Auctions for Procurement Operations

We present nine papers on e‐auctions for procurement operations. The first of the issue's three sections is a foreword highlighting current trends and future research directions. The second section is composed of three commissioned survey papers, covering auctions within e‐sourcing events, electronic markets for truckload transportation, and games and mechanism design in machine scheduling. The final section consists of five research papers on the following topics: whether auction parameters affect buyer surplus in e‐auctions for procurement, collusion in second‐price auctions under minimax regret, the effect of timing on jump bidding in ascending auctions, market‐based allocation with indivisible bids, and ranked items auctions and online advertisement.     

An Analysis of Scoring and Buyer‐Determined Procurement Auctions

In procurement auctions, the object for sale is a contract, bidders are suppliers, and the bid taker is a buyer. The suppliers bidding for the contract are usually the current supplier (the incumbent) and a group of potential new suppliers (the entrants). As the buyer has an ongoing relationship with the incumbent, he needs to adjust the bids of the entrants to include non‐price attributes, such as the switching costs. The buyer can run a scoring auction, in which suppliers compete on the adjusted bids or scores, or, he can run a buyer‐determined auction, in which suppliers compete on the price, and the buyer adjusts a certain number of the bids with the non‐price attributes after the auction to determine the winner. Unless the incumbent has a significant cost advantage over the entrants, I find that the scoring auction yields a lower average cost for the buyer, if the non‐price attributes are available. If the non‐price attributes are difficult or expensive to obtain, the buyer could run a buyer‐determined auction adjusting only the lowest price bid.     

Increasing Revenue by Decreasing Information in Procurement Auctions

We report on results of several laboratory experiments that investigate on‐line procurement auctions in which suppliers bid on price, but exogenous bidder quality affects winner determination. In procurement auctions, bidder quality may or may not be publicly known to all bidders, and the effect of this quality transparency on the auction outcome is one aspect of auction design that we examine. The second aspect of auction design that we examine is the effect of price visibility on the auction outcome, and the interaction between price visibility and quality transparency. In terms of price visibility, we consider two extreme cases: the sealed bid request for proposals (RFPs), and the open‐bid dynamic auction event. In terms of bidder quality transparency, we also consider two extreme cases: a setting in which bidder qualities are publicly known and the case in which they are private. We find that in our laboratory experiments, the RFP format is consistent in generating higher buyer surplus levels than does the open‐bid dynamic format. This advantage is independent of the quality transparency. In contrast, the open‐bid format is highly sensitive to quality transparency, generating significantly lower buyer surplus levels when the information about bidder quality is public.     

An Experimental Investigation of Procurement Auctions with Asymmetric Sellers

Electronic reverse auctions are a commonly used procurement mechanism. Research to date has focused on suppliers who are ex ante symmetric in that their costs are drawn from a common distribution. However, in many cases, a seller's range of potential costs depends on their own operations, location, or economies of scale and scope. Thus, understanding how different bidder types impact auction outcomes is key when designing an auction. This study reports the results of the first controlled laboratory experiment designed to compare prices between first‐price and second‐price procurement auctions for homogeneous goods when seller cost types are asymmetric and the number of bidders varies. The results indicate that first‐price auctions generate lower prices regardless of market composition. The results also reveal that first‐price auctions are at least weakly more efficient than second‐price auctions despite the theoretical prediction that the reverse should hold in asymmetric auctions. Post hoc analysis of individual bidders' behavior in first‐price auctions revealed evidence that bidders systematically underbid when their cost realizations were close to the lower bound. Furthermore, bidders adjust their behavior based on the type of the other bidders in the market in a manner inconsistent with theory. Consequently, adding a third bidder to a two‐bidder market is not advantageous to the buyer unless that third bidder is a low‐cost type.     

考虑再谈判的网上服务采购多属性拍卖研究

针对在线服务外包,研究了供应商投标服务方案(体现服务质量)和价格的买方决定制多属性采购拍卖,分析了交易双方关于服务内容的再谈判对供应商投标均衡、买方初始服务内容决策和各方期望利润的影响。结果表明,无再谈判情形下,供应商的服务质量投标均衡和信息租金都随初始服务内容递增;而有再谈判情形下,尽管买方对服务质量的评标权重随初始服务内容递增,但供应商服务质量、信息租金及买方期望利润都不受初始服务内容影响。换言之,初始服务内容对采购项目的规制作用被再谈判完全替代。不仅如此,相较于无再谈判情形,再谈判的存在能够激励供应商提供更高的服务质量,并促成更多的服务内容成交,最终使买方、获胜供应商和交易平台都获得更高期望利润。     

供应风险下双源采购批发单价拍卖最优设计

考虑多个具有供应风险和成本私有信息的潜在供应商,研究了供应商投标批发单价的最优双源采购拍卖机制设计.首先,针对一般的采购商收益函数,求出了最优的订货量分配规则和供应商投标均衡,并分别与单源采购及对称信息对比,发现双源采购拍卖增加了采购商和供应商的期望利润,不对称信息对供应商有利但对采购商和供应链不利.然后,分别针对报童及垄断环境,进一步分析了双源采购拍卖下的订货分散程度、信息价值和双源采购价值,发现,订货分散程度与供应风险及两个获胜者的利润率贡献相近程度正相关;高成本获胜者比成本较低者索取更高的单位信息租金,导致不对称信息下的订货分散程度比对称信息下低;供应风险越高或投标人数越多时,双源采购价值越大.     

Looking Upstream: Optimal Policies for a Class of Capacitated Multi‐Stage Inventory Systems

We consider a multi‐stage inventory system with stochastic demand and processing capacity constraints at each stage, for both finite‐horizon and infinite‐horizon, discounted‐cost settings. For a class of such systems characterized by having the smallest capacity at the most downstream stage and system utilization above a certain threshold, we identify the structure of the optimal policy, which represents a novel variation of the order‐up‐to policy. We find the explicit functional form of the optimal order‐up‐to levels, and show that they depend (only) on upstream echelon inventories. We establish that, above the threshold utilization, this optimal policy achieves the decomposition of the multidimensional objective cost function for the system into a sum of single‐dimensional convex functions. This decomposition eliminates the curse of dimensionality and allows us to numerically solve the problem. We provide a fast algorithm to determine a (tight) upper bound on this threshold utilization for capacity‐constrained inventory problems with an arbitrary number of stages. We make use of this algorithm to quantify upper bounds on the threshold utilization for three‐, four‐, and five‐stage capacitated systems over a range of model parameters, and discuss insights that emerge.     

Combined Pricing and Portfolio Option Procurement

In this paper, we study a single‐product periodic‐review inventory system that faces random and price‐dependent demand. The firm can purchase the product either from option contracts or from the spot market. Different option contracts are offered by a set of suppliers with a two‐part fee structure: a unit reservation cost and a unit exercising cost. The spot market price is random and its realization may affect the subsequent option contract prices. The firm decides the reservation quantity from each supplier and the product selling price at the beginning of each period and the number of options to exercise (inventory replenishment) at the end of the period to maximize the total expected profit over its planning horizon. We show that the optimal inventory replenishment policy is order‐up‐to type with a sequence of decreasing thresholds. We also investigate the optimal option‐reservation policy and the optimal pricing strategy. The optimal reservation quantities and selling price are shown to be both decreasing in the starting inventory level when demand function is additive. Building upon the analytical results, we conduct a numerical study to unveil additional managerial insights. Among other things, we quantify the values of the option contracts and dynamic pricing to the firm and show that they are more significant when the market demand becomes more volatile.     

A Portfolio Approach to Procurement Contracts

The purpose of this paper is to develop a general framework for supply contracts in which portfolios of contracts can be analyzed and optimized. We focus on a multi‐period environment with convex contract, spot market, and inventory holding costs. We specialize the model to the case of a portfolio consisting of option contracts. We characterize the optimal replenishment policy and show that it has a simple structure. Namely, the use of every different option contract and the spot market is dictated by a modified base‐stock policy. In addition, we derive conditions to determine when an option is relatively attractive compared to other options or the spot market. Finally, we present our computational study, where we report the sensitivity of the results to the parameters of the model. Our experiments indicate that portfolio contracts not only increase the manufacturer's expected profit, but can also reduce its financial risk.     

不完全信息采购环境下的供应链协调问题： 拍卖机制的应用

本文研究了不完全信息采购环境下供应链的协调问题.拍卖不仅是一种价格确定机制,它也可以作为一种供应链协调的机制.文献已经证明拍卖机制对于参与方的收益及整条供应链的有效性具有显著影响.本文研究了当市场中存在n个供应商1个买者的情形下,拍卖环境满足独立私人值(IPV)条件、且市场反需求函数为对数函数时,批发价格拍卖、目录拍卖及二部合同拍卖为各方所产生的期望收入,并且证明了批发价格拍卖和目录拍卖不能实现渠道协调,而在拥有信息中介的二部合同拍卖机制下系统可以达到渠道协调.     

拍卖采购合同及议价谈判机制设计

考虑采购商在多个潜在供应商中选择1名获胜者来提供单物品或服务,并且供应商存在不可见努力的情况,设计了两阶段采购机制.该机制先实施关于合同的拍卖阶段,再执行可能的议价谈判阶段.分析的基本结论是,在对称信息情况下,存在系统最优的质量标准和努力水平;不对称信息下,投标者将在拍卖阶段报价自己的真实成本.在不对称信息的谈判阶段,存在包含重新确定的价格、质量和努力水平的惟一议价均衡,此均衡将实现对称信息下的分配效率——系统最优.从采购商的利益出发,给出了采购商选择采取谈判策略或者采用拍卖阶段合同的条件.     

应急期间服务运作系统能力的采购和恢复模型

分析了大型服务运作系统应急期间的能力应急管理模式,围绕系统内部能力恢复和外部能力采购,综合考虑社会惩罚成本,以应急期间的总成本最小为目标构建了相应的数学模型。通过数值仿真得到4个重要的管理学结论,对社会管理部门的应急政策制定以及运作系统本身在应急期间的科学决策均具有重要的指导意义。     

基于遗传算法的装备采购决策优化研究

在装备采购中,由于需求单位地域分布和担负的任务各不相同,对装备的品种、数量、时限要求也就不一样,如何使装备采购科学化、合理化,是一个涉及多变量、多目标的复杂系统问题。在综合考虑装备采购各项因素的基础上,构建多约束条件下的多目标模糊指派模型,提出了基于遗传算法的解决方案,最后通过案例进行仿真实验,验证该算法的可行性和有效性,解决了采用传统优化方法难以解决的装备采购优化决策问题。     

基于智能电网技术的能源网络供应链买电策略研究

智能电网的提出不仅是电网技术本身发展的需要,更是各国能源和经济发展战略层面的需要。可再生能源作为清洁能源的突出代表,其分布式发电系统是智能电网发展的必然趋势。但是,由于天气等因素导致的可再生能源高度不确定性和间歇性却给智能电网系统的稳定带来很大挑战。为了应对这一挑战,并发挥可再生能源的成本优势,本文从微观运营的角度,研究带有可再生能源供给的"多对多"能源网络供应链的买电决策问题,求得能源集成商的最优买电量,以及能源短缺成本、发电厂产能、可再生能源不确定性等参数对最优解的影响。本文发现,发电厂产能对能源集成商使用可再生能源的策略有直接影响。并且,可再生能源产能较大的能源集成商因为规避不确定性风险反而会提高买电量。本文的结论能帮助智能电网节省用电成本,为实现节约型、可靠型和稳定型电网系统提供一定参考。     

多因素采购组合拍卖动态机制设计研究

在允许"价格-质量"投标的多因素投标环境下,设计了一种多因素采购组合拍卖的动态机制(规则),提出了竞争均衡打分的概念。构建了多因素采购组合拍卖动态机制的优化模型,讨论了拍卖规则和优化模型实现互补松弛条件之间的必然联系。基本结论是:在本拍卖机制中,投标者采用最佳近视反应投标策略,将使拍卖的分配结果趋向最优,最终在拍卖结束时实现系统效用最大化。     

Do Auction Parameters Affect Buyer Surplus in E‐Auctions for Procurement?

Although the initial euphoria about Internet‐enabled reverse auctions has given way to a cautious but widespread use of reverse auctions in business‐to‐business (B2B) procurement, there is a limited understanding of the effect of auction design parameters on buyer surplus. In this paper, we study the effect of bidding competition, information asymmetry, reserve price, bid decrement, auction duration, and bidder type on buyer surplus. We collected field data on more than 700 online procurement auctions conducted by a leading auctioneer and involving procurement items worth millions of dollars. Consistent with the predictions of auction theory, the results indicate that bidding competition, reserve price, and information sharing affect buyer surplus. Unlike previous findings in the consumer‐to‐consumer context, we find that bid decrement and auction duration have no effect in B2B procurement auctions. Our results suggest that use of the rank‐bidding format increases buyer surplus when incumbent suppliers participate in the auction. We discuss the theoretical and managerial implications of these findings for future research and for optimal design of online procurement auctions.     

现货价格和需求关联时期权组合合约模式下采购风险管理策略

在现货价格和客户端需求关联的情形下,本文引用期权组合合约建立现货市场供应量有限时的两阶段采购风险管理模型,以期最大化零售商的期望收益。文中先用逆向归纳法列出零售商第二阶段的最优策略,采用标准扰动定理得出有效合约应满足的最优性条件,并将原模型转化为单调的最短路径问题,应用动态规划求解最优的采购策略。最后用算例分析了现货价格与需求的相关系数及现货市场的供应量对最优策略的影响,发现当供应量一定时,各有效合约的最优预订量及有效合约的总预订量都随着相关系数的增大而提高,并且有效合约受相关系数的影响大小取决于合约的灵活性;并且,当相关系数一定时,有效合约的总预订量及执行价格最低的有效合约的最优预订量都随着供应量的增加而单调减少。     

Dynamic Procurement,Quantity Discounts,and Supply Chain Efficiency

We study a model with a single supplier and a single buyer who interact multiple times before the buyer sells her product in the end‐consumer market. We show that when the supplier uses a wholesale price contract, even under perfect foresight, the supplier, the buyer, and the end consumers benefit from multiple trading opportunities versus a one‐shot procurement agreement.     

Vehicle Procurement Policy for Humanitarian Development Programs

This article aims to identify optimal vehicle procurement policies for organizations engaged in humanitarian development programs and to derive general insights on the characteristics of these policies. Toward that end, we follow an inductive approach. First, we study the operations of the International Committee of the Red Cross (ICRC) in three representative countries: Sudan, Afghanistan, and Ethiopia. Using a linear programming (LP) model primed with field data provided by the ICRC, we calculate the optimal vehicle fleet size and compare it with the policies actually implemented. Second, drawing from results of the LP model, we develop a stylized quadratic control model and use it to characterize the general structure of the optimal policy under different demand scenarios and operational constraints. After demonstrating that the results of the control model are consistent with those of the LP model in the specific context analyzed, we discuss the optimal policies and the applicability of the former as a practical tool for strategic asset planning.