Acquisition of supply market intelligence – An information processing perspective

The capability to develop and sustain superior knowledge of markets and supply chains, or supply market intelligence (SMI), is an important element in increasing the strategic relevance of purchasing and supply management (PSM). This study draws on information processing theory (IPT) to shed light on how firms acquire SMI. In particular, the study aims to identify the drivers and mechanisms of information processing in SMI acquisition and to explore how the two constructs are related. Our findings emerged from an abductive multiple case study including 22 SMI tasks in eight case companies operating in various manufacturing industries. We find that the drivers of information processing needs in SMI acquisition are related either to uncertainty or equivocality. Uncertainty describes a situation in which decision-makers may be ignorant of a variable's value while equivocality describes a situation in which they may be ignorant of the variable's existence. We identify four structural mechanisms and three information technology mechanisms for information processing in the SMI context. We also find that equivocality seems to trump uncertainty in determining the use of the identified SMI acquisition mechanisms. In addition to elaborating IPT in the SMI context and exploring the theoretical foundations of SMI, we offer practitioners a framework for supporting the design of SMI practices in procurement organisations.     

Strategic inventory in capacitated supply chain procurement

We study the strategic role of inventory in a sequential two‐period procurement setting, where the supplier's capacity in the first period is limited and the retailer has the option to hold inventory. We compare the equilibrium under a dynamic contract, where the decisions are made at the beginning of each period, and a commitment contract, where the decisions for both periods are made at the beginning of the first period. We show that there is a critical capacity level below which the outcomes under both types of contracts are identical. When the first period capacity is above the critical level, the retailer holds inventory in equilibrium and the inventory is carried due to purely strategic reasons; as capacity increases, so does the strategic role of inventory. The supplier always prefers lower capacity than the retailer, and the difference between supplier‐optimal and supply‐chain optimal capacities, and the corresponding profits, can be significant. Finally, we find that the retailer's flexibility to hold inventory is not always good for the participants or for the channel. Copyright © 2008 John Wiley & Sons, Ltd.     

对在企业集团内部实行财务集成管理的几点分析

实行财务集成管理可以实现缩短生产前置时间,提高产品质量和服务质量、提高企业的整体柔性、减少库存等,现对其进行简要分析。     

A lot sizing and sequencing algorithm for dynamic demands upon a single facility

A heuristic algorithm is developed and applied to determine lot sizes and production sequence on a single facility. The various product demands are treated as deterministic and time varying (dynamic) over a finite planning horizon, such as that generated from a material requirements planning (MRP) system.In contrast to other approaches available, the algorithm considers the sequencing decision in each period by realistically assuming inventory holding cost occurrence in the period of production, and in addition, it is capable of considering set-up times where such set-up times consume available productive capacity. The ability to handle numerous products, and the capability of being able to specify maintenance time and holidays is an integral aspect of the algorithm.The results of an application of the algorithm in a medium size bearing company have shown very significant reduction in the controllable inventory holding cost while eliminating late deliveries. In an effort to cope with potential realistic schedule alterations, different solutions were developed for managerial evaluation providing greater flexibility but at a higher cost.     

供应链环境下信息共享对库存的影响研究

实现供应链管理的关键是信息共享。通过文献综述,对供应链环境下,信息共享对库存的影响进行了分析和研究。并对牛鞭效应、VMI、采购承诺和数量柔性与信息共享的关系进行讨论,最后得出了供应链环境下,信息共享的障碍。     

精益物流研究综述

精益思想的理论产生以后,在物流领域得到迅速发展与应用,并取得较好的成效。文章在总结国内外精益物流相关理论及运作方面的研究成果基础上,从精益物流的概念、运作、供应商、库存和成本管理等方面分别进行了归纳阐述,强调指出供应商评价与选择的方法、JIT库存管理及成本管理在实施精益化过程中至关重要,这对于减少浪费、降低成本、提高顾客满意度等有重要作用,同时提出精益物流的未来发展趋势及研究展望,将绿色和电子商务融入精益物流的研究中,增强柔性和敏捷性,最终实现物流的精益化。     

Automotive supplier parks: An imperative for build-to-order?

Build-to-order (BTO) has been hailed as a production strategy that fits the demands of the 21st century where a considerable challenge for the industry is how to achieve flexibility from extended supply chains that span the globe and retain elements of make-to-forecast. A study of 8 European manufacturers examines whether supplier parks are an imperative for BTO using a conceptual framework developed from the literature. The findings question the idea that simply locating suppliers in close proximity to original equipment manufacturer assembly plants reduces delivery lead time and inventory. Hence, not all types of supplier parks are an imperative for BTO, where the cases reveal a wide variety of types ranging in scale and proximity. The originality of the paper is a unique study which redefines both automotive supplier park terminology and the relationships with BTO. It questions received wisdom and offers practical measures for industry.     

Perceived versus actual value of product substitution flexibility: An experimental investigation

Prior literature suggests that in the presence of operational uncertainties such as uncertain demand, firms should deploy operational flexibilities. However, these flexibilities are costly to develop and a correct valuation of these capabilities is necessary to ensure that they are only deployed when the expected benefits exceed the cost. Using a set of behavioral decision-making experiments for inventory of substitutable products, we investigate how decision-makers perform when estimating the value of operational flexibility of product substitution. We found that subjects consistently overestimated the monetary value of product substitution. Furthermore, the overestimation became more acute as demand correlation increased. This behavior is not explained by risk aversion or random errors. Instead, it appears to be driven by fundamental and systematic behavioral biases when estimating the conjunctive probability of substitution. We suggest and validate a decomposition-based approach to mitigate this overestimation.     

The impact of vertical integration on inventory turnover and operating performance

This paper investigates how vertical integration may influence inventory turnover and firm operating performance. A causal model is developed to investigate the effects of vertical integration on three types of inventory, namely raw materials inventory (RMI), work in progress inventory (WIPI) and finished goods inventory (FGI). The model tests the interactions between inventory types and the consequences of inventory turnover performance on various aspects of firm performance including costs and profitability. In particular, path analysis supports systematic differences with respect to how vertical integration affects RMI, WIPI and FGI. Vertical integration has a positive effect on RMI and FGI turnover but no significant effect on WIPI turnover. FGI contributes to a reduction in supporting processes costs which causes an improvement in return on sales (ROSs). Vertical integration impacts ROS directly.     

考虑多种产品的随机库存系统仿真及优化研究

结合现实库存状况,利用可视化通用交互集成仿真软件Arena建立包含多个产品的库存控制系统模型,得到给定(s,S)的平均库存成本。最后利用模型参数优化器Optquest辅助求解最优结果及对应的(s,S),达到平均库存成本的最小化。另外,客户对于缺货状况的不同态度直接影响到缺货成本的计算,因此建模时也将此因素考虑在内。     

供应链环境下基于服务水平约束的联合库存模型

联合库存(JMI)是供应链库存管理研究的一个热点,近年来引起了不少学者的注意。联合生产库存模型是研究联合库存策略的主要模型之一。考虑一个典型的单一产品的二级供应链系统:单供货商(卖方)-单销售商(买方),假定企业不允许缺货以及外部对买方的需求量是一个服从正态分布的随机变量,建立了基于服务水平约束的联合生产库存模型;利用文献[6]中的数值例子验证了模型的有效性,文章同时也为联合库存策略的实施提供了一种简单易于控制的思路和方法。     

A new focus on inventory performance and bottom-line profits

This article is about a new way to measure inventory performance and about putting a dollar focus on inventory management priorities. It reviews the financial impact of inventories and shows how the information from any materiel requirements planning (MRP), MRP II, ERP, DRP, or orderpoint system can be used for setting individual objectives for inventory reduction, measuring performance by inventory segment, and monitoring continuous improvement. It will also consider the merits of paying performance bonuses to materiel planners and review some inventory reduction results.     

What inventories tell us about aggregate fluctuations—A tractable approach to (S,s) policies

We estimate a DSGE model with (S,s) inventory policies. We find that (i) taking inventories into account can significantly improve the empirical fit of DSGE models in matching the standard business-cycle moments (in addition to explaining inventory fluctuations); (ii) (S,s) inventory policies can significantly amplify aggregate output fluctuations, in contrast to the findings of the recent general-equilibrium inventory literature; and (iii) aggregate demand shocks become more important than technology shocks in explaining the business cycle once inventories are incorporated into the model. An independent contribution of our paper is that we develop a solution method for analytically solving (S,s) inventory policies in general equilibrium models with heterogeneous firms and a large aggregate state space, and we illustrate how standard log-linearization methods can be used to solve various versions of our inventory model, generate impulse response functions, and estimate the model׳s deep structural parameters.     

化工企业实施供应商管理库存的研究

随着市场竞争加剧，化工企业的供应链管理越来越引起人们的重视。供应链管理中，如何处理化工企业普遍存在的库存量高、库存周转率低、流动资金占有量大等问题成为供应链管理的重点。供应商管理库存（VMI）是一种供应链环境下新的库存管理方式，它能够对改善整个供应链库存状况、降低系统库存总成本起到积极的作用。本文针对化工企业生产及物料供应特点提出采用VMI模式的动因、方法及注意事项，以期解决化工企业库存的问题，对化工企业供应链库存管理提供帮助。     

超市库存商品的需求预测

超市中的库存管理就是对各种商品进行保管与控制,如果库存中的商品留存过多,则会造成资金的浪费．进而影响效益;如果库存中的商品留存过少,当有顾客需要时不能有效的提供,影响企业信誉。因此,对于库存量的把握就成为了库存管理的关键。所以对库存商品的需求预铡是非常必要的。文章用GM（1,1）模型对库存商品进行需求预测,并进行精度、关联度分析,得出了较准确的结论,对超市库存管理者具有指导意义。     

电子商务中的多级供应链库存成本研究

在考虑多级供应链的情况下,对电子商务中的传统库存管理模式和供应商管理库存（VMI）模式建立库存成本模型;并运用遗传算法进行模拟分析。该多级供应链由多个原材料供应商、一个核心制造商、多个销售商以及客户组成。通过对两种库存管理模式的比较分析,得出在电子商务中引入VMI模式后,库存成本得到明显降低。     

MJO库存控制模型研究

寻找有效的库存控制方法对企业提高运营效率意义重大。整合物料需求计划(MRP)、准时化生产(JIT)和最优生产技术(OPT)三种方法而成的M JO库存控制模型,可以做到既保证客户服务水平,又不占用过多资金,是实现有效库存控制,进而提高运营效率的重要手段。     

集群式库存管理

本文针对产业集群这一特征，提出了集群式库存管理技术。且该文建立了基于集群式库存管理的模型。根据该模型推导出了在产业集群中生产商分开管理原材料库存和库存管理公司管理原材料库存的库存相关成本．并进行了比较。得出如下重要结论：基于集群式库存管理的原材料库存管理的库存相关成本得到了明显降低。     

生产物流实现零库存的一种有效途径

库存是资产也是万恶之源,沉重的库存负担,不仅占用大量的资金,更难与现代企业的精益生产、敏捷制造和追求小批量、多批次、多品种采购供应模式相匹配。库存问题已不再仅表现为企业库存管理的能力,更上升为企业与供应商的协作关系,在供应链上许多企业都在探讨行之有效的库存管理方法。零库存是生产企业追求的最佳库存状态,如何实现零库存有许多具体的方法和管理策略。主要详细介绍了生产物流实现零库存的一种有效的途径——寄售零库存法。     

Irregular workloads with MRP systems: Some causes and consequences

Material Requirements Planning (MRP) systems have been widely applied in industry to better manage multiproduct, multistage production environments. Although many applications have been quite successful, much is still left to the planner's intuition as to how to assure that master schedules, component lot sizes, and priorities realistically conform to the capacity limits at individual work centers. Capacity issues may indeed be the soft spot in MRP logic.This paper explores some possible causes of irregular workload patterns when using an MRP system. Better insight on which factors cause temporary bottlenecks could help managers better assess the vulnerability of their plants to this problem. It might also suggest ways of dampening peaks and valleys. The problem setting is a multistage environment; several products are made from various subassemblies and parts. Each shop order is routed through one or more capacitated work centers. An order is delayed either by temporary capacity shortages or the unavailability of components. Of course, the second delay can be caused by capacity problems previously encountered by the shop orders of its components.Seven experimental factors are tested with a large-scale simulator, and five performance measures are analyzed. The factors are the number of levels in the bill of material, the average load on the shop, the average lot size, the choice of priority rule, demand variability, the use of a gateway department, and the degree of equipment specialization. We have one measure of customer service, two for inventory, and two for workload. The workload measures are unconventional, since our interest is when workload variability occurs and how it affects inventory and customer service.The simulator has been developed over the course of eight years, and since this study has been further enhanced to handle many more factors. The simulator was validated recently with real data at two manufacturing plants. It is quite general, in that the bills of material, shop configuration, routings, worker efficiencies, and operating rules can be changed as desired.An initial screening experiment was performed, whereupon the average load and priority rules were not statistically significant at even the .05 level. A full factorial analysis with two replications was then conducted on the five remaining factors. Multivariate analysis of variance (MANOVA) and analysis of variance (ANOVA) statistical tests have been performed.The results confirm that workload variability can have a detrimental impact on customer service and inventory. The following structural changes to the manufacturing system can be beneficial, but tend to be more difficult to achieve. More BOM levels improve customer service, but increase inventory and capacity bottlenecks. Resource flexibility is a powerful tool to reduce workload variability. Capacity slack averaging much over 10% is wasteful, having no benefits for inventory and customer service. In general, revising the routing patterns only, such as creating more dominant paths, will not give big payoffs. The following procedural changes are easier to implement. Master schedules which smooth aggregate resources are an excellent device to reduce workload variability. Even with a smooth MPS, debilitating workload variability can still occur due to the design of the BOM, lot size, and leadtime offset parameters. Selecting a priority rule does not seem to be of overriding importance compared to master scheduling and component lot sizing. These findings must be considered within the context of the range of plant environments encompassed by this study.