Flexible work-in-process production system in supply chain management under quality improvement

For a complex product production, any flexible manufacturing system with a work-in-process inventory is recommended for a supply chain management (SCM) system. Building a flexible manufacturing system increases the total cost of the supply chain; for this reason, a discrete investment is important. For flexible production systems, production rate within a finite specific interval of production rate as work-in-process inventory is calculated. The aim of the supply chain is to reduce the total cost when demand during the lead time is a random variable with a normal distribution. A crashing cost is utilised to reduce the duration of lead time within the supply chain system. A model is proposed to obtain the optimal flexible production rate with the reduced total cost of the supply chain. A classical optimisation technique is employed to obtain the closed-form and quasi-closed-form solutions of the decision variables. An improved algorithm is designed to obtain the global minimum cost of SCM under the framework of a flexible production system. An illustrative numerical example and sensitivity analysis are given to test the model. A numerical study proves that this model obtains the minimum cost with the optimal decision variables.     

An analysis of manufacturers’ supply and demand uncertainty based on the dynamic customisation degree

Diverse demands regarding products are common; however, manufacturers usually cannot respond immediately to meet such changes upon demand, and thus, customer satisfaction tends to be reduced. Notebook computer manufacturers adopt a production mode of mass customisation; hence, a certain degree of dynamic customisation measurements, inherent in different supply chain models, allow manufacturers to evaluate costs and profits in advance. The application of the model, as proposed in this study, indicates that the most important factor of the customisation degree is product price. The dynamic customisation degree is adjusted based on monitoring indicators, which requires less total cost and produces greater accuracy in forecast results regarding the prediction model of customer demands. This study develops a dynamic customisation model for total product profits, inventory cost of semi-manufactured products, shortage costs and buffer inventory costs, which are affected by the degree of dynamic customisation of the products. It also analyses the supply and demand uncertainties of the Direct Shipment of the Manufactured Model, as well as the Door-to-Door Direct Shipment of the End User Model in the notebook computer industry, as the criteria with respect to a firm's customisation degree, costs, and profits in different supply chain mode operations.     

Selection of management accounting systems in Just-In-Time and Theory of Constraints-based manufacturing

In today's competitive business environments, a firm's long-term survival rests heavily on its ability to sustain manufacturing superiority over its competitors. To provide the firm with detailed guidelines for sustaining manufacturing superiority, this paper examines the impact of different management accounting systems, manufacturing control systems and time horizon on manufacturing performance in an enterprise resource planning integrated environment. These management accounting systems include traditional costing, activity-based costing and throughput accounting. The manufacturing control systems include Just-In-Time- and Theory of Constraints-based manufacturing. Through a series of simulation experiments, it was found that activity-based costing provided higher short- and long-term profit, better customer service and lower work-in-process inventory than traditional costing and throughput accounting in situations where firms have high overhead costs and relatively low labour and material costs, while carrying ending inventories because of demand uncertainty. Traditional costing also outperformed throughput accounting by exploiting the real-time information sharing capabilities of an enterprise resource planning system. Just-In-Time manufacturing outperformed Theory of Constraints with respect to short- and long-term profitability, customer service, and work-in-process inventory because of differences in buffer inventory policies and sequencing rules. However, time horizon and its interaction with management accounting systems had no impact on the manufacturing performance. In addition, the results suggest that a management accounting system that depicts the manufacturing process tended to provide more accurate product cost information and resulted in a better system performance than the others.     

Integration of global manufacturing networks and supply chains: a cross case comparison of six global automotive manufacturers

Striving for new business opportunities automotive original equipment manufacturers established overseas plants in emerging markets and global manufacturing networks evolved. In this regard so-called knocked down supply chains have been the key for the establishment of successful overseas operations. Importing all parts required from the original plants in form of easy to be handled kits secures a high product quality and stable supply despite lacking qualification of local workforce and supplier bases. Over time the overseas plants and global manufacturing networks have matured by increasingly taking over value adding processes and integrating local suppliers. However, the supply chain structure and management have not been adapted accordingly and still comprise high inventory buffers and lead times. There is little research on the integrated design of global manufacturing networks and knocked down supply chains. This research aims to contribute to close this research gap by means of a cross-case study with six globally operating OEMs investigating the fit of knocked down supply chains and global manufacturing networks. On the basis of transaction cost theory, we develop an integrated framework to align global manufacturing networks and knocked down supply chain design that can serve as guideline to open logistics performance and cost potentials.     

制造企业库存长鞭效应影响因子分析及控制方法

长鞭效应是供应链管理中由于供应链合作伙伴之间缺乏合作与协调的结果。从理论上刻画了长鞭效应的内在本质,分析了产生长鞭效应的原因,以一个跨国公司的库存管理为例,详细分析了影响长鞭效应三个方面的因子：（1）集中式与分散式管理;（2）需求与供应特征;（3）产品类型与库存再订货点。还从供需合作关系的角度提出了改善长鞭效应的几个控制方法。     

Product recovery optimization in closed-loop supply chain to improve sustainability in manufacturing

When business practices shift from a traditional open supply chain to a closed loop instead, the environmental and societal issues are efficiently integrated in business development. However, even an efficiently integrated shift introduces a number of trade-offs due to the contradictory goals that emerge from that business’s economical, environmental and social dimensions. In this paper, we propose a multi-objective mixed integer mathematical problem for a generic closed-loop supply chain (CLSC) network to rationalise how a system’s product recovery helps to improve manufacturing sustainability. The CLSC network proposed in this study consists of a hybrid manufacturing facility, warehouse, distribution centres, collection centres and a hybrid recovery facility (HRF). The proposed model determines the best location for the HRF and optimal flow of products, recovered parts and material in the network while it simultaneously maximises profit, saves activity costs, helps to decrease the harmful effects of the manufacturing process and makes a positive impact on societal development. To validate the model, a numerical illustration with the help of a case study from an electrical manufacturing industry is offered. The results authenticate the approach of the model towards the fulfilment of various environmental regulations. A sensitivity analysis, completed on demand, and the return rate also assists decision-makers to manage their decisions with a broader insight towards manufacturing sustainability.     

An impact of manufacturing flexibility and technological dimensions of manufacturing strategy on improving supply chain responsiveness: Business environment perspective

The main objective of this research is to investigate the impact of manufacturing flexibility and technological dimensions of manufacturing strategy on responsiveness in the supply chain. Based on the theoretical background of dynamic capability, this study also examines the role of the business environment on the relationship between manufacturing flexibility and supply chain responsiveness. 144 structured surveys were collected and the partial least squares of structural equation modelling approach were utilised for data analysis. The result establishes relationships among various dimensions of manufacturing flexibility. Although the technological dimensions in manufacturing strategy of such advanced manufacturing technology (AMT) and e-procurement do not have any direct impact on new product and market flexibility, they increase supply chain responsiveness, which helps to react quickly against supply chain disruptions. More importantly, the business environment has a moderating effect on the relationship between market flexibility and supply chain responsiveness.     

Inventory performance of some supply chain inventory policies under impulse demands

This paper attempts to study the impact of impulsive demand disturbances on the inventory-based performance of some inventory control policies. The supply chain is modelled as a network of autonomous supply chain nodes. The customer places a constant demand except for a brief period of sudden and steep change in demand (called demand impulse). Under this setting, the behaviour of each inventory policy is analysed for inventory performance of each node. It is found that the independent decision-making by each node leads to a bullwhip effect in the supply chain whereby demand information is amplified and distorted. However, under a scenario where the retailer places a constant order irrespective of the end customer demand, the inventory variance was actually found to decrease along the supply chain. The variance of the inventory remained constant along the chain when only the actual demands are transmitted by each node. The results also showed that the inventory policy which is best for one supply chain node is generally less efficient from a supply chain perspective. Moreover, the policy which performs poorly for one node can be most efficient for the supply chain. In a way, our results also provide a case for coordinated inventory management in the supply chain where all members prepare a joint inventory management policy that is beneficial for all the supply chain nodes. The results have significant industrial implications.     

A dynamic system model for proactive control of dynamic events in full-load states of manufacturing chains

Risk management is a major concern in supply chains that have high levels of uncertainty in product demand, manufacturing process or part supply. The uncertainties frequently manifest as dynamic events that pose a threat to interrupting supply chain operation. Depending on the nature and severity of uncertainty, the impact of dynamic events can be distinguished into three categories: deviation, disruption, and disaster. Many studies in literature addressed modelling of deviation events. In this paper, a dynamic system model of supply chains is described which can be applied to managing disruptive events in full-load states of manufacturing chains. An example of disruptive events is given which arises from demand shocks in distribution channel. The procedure to construct full-load production functions of complex manufacturing nodes with internal queuing delay is described. Analytic optimal solution is derived for the dynamic model. Given an unordinary event of demand shock, this model can be used to determine if demand shock can be absorbed by a manufacturing chain and the level of contingent resources that must be synchronously activated in multiple nodes of the chain. This model can be used to reduce what could have been a disruptive event into a deviation event, thus enhancing risk management.     

Selection of risk mitigation strategy in electronic supply chains using grey theory and digraph-matrix approaches

Supply chains are becoming more lengthy and complex due to globalisation and vertical integrations. In this context, adopting proactive approaches is needed for dealing with changing risks and vulnerabilities for securing supply chain systems. Supply chain risks are interlinked and thus, one mitigation strategy can reduce many of other supply chain risks. For example, aggregate or pooling demand reduces forecast risks, capacity risks and inventory risks. Also, some of the risk mitigation strategies have negative influences over certain supply chain risks as adding capacity has a negative influence on capacity risks. Twelve major supply chain risk categories and 21 risk mitigation strategies with typical focus on electronics manufacturing supply chains have been identified. A combination of grey theory and digraph-matrix methodologies has been used for quantifying various supply chain risk mitigation strategies and this approach is not seen in literature till date. The proposed model was also tested taking a case study of an Indian electronics manufacturing company. Obtained results were also subject to sensitivity analysis. The net positive influence values of risk mitigation strategies proposed in this research could effectively be used by top management for ascertaining their risk mitigation strategies for better management of supply chains as a whole.     

Analysis of a multi-component periodic review inventory system in an assembly environment

Inventory systems within production or distribution chains typically interact with preceding supply and successive demand processes. We observe that the more clearly the performance characteristics of an inventory system are described and communicated, the better the planning and configuration of the surrounding systems can be. This paper is thus dedicated to the analysis of a component inventory model that is typically found within multi-level supply chain structures. Operating on a discrete time axis, we assume that lead times are discretely distributed, and may also depend on preceding occurrences. Customer demand for the components emerges from a single end product that requires all of the components, and whose demand per period is continuously i.i.d. The components are replenished according to a periodic review order-up-to (r, S ^[i]) policy, where r is common to all components and S ^[i] may be selected individually. Particularly, we discuss the modeling of the lead time process and give a detailed analysis of the delay time process versus the successive level of the supply chain. The analysis is exact and has not so far been conducted on the delay time of a comparable system. We have given special emphasis to elaborating the relevant formulae and computational approaches to a level at which they are ready to be computed.     

面向供应链的制造业库存决策支持系统的分析与设计

从制造型企业自身的特点出发,结合供应链环境下制造商库存管理的对象和方法,在分析库存决策机制的基础上,设计了供应链环境下面向制造业的库存决策支持系统,并讨论了本系统数据仓库的设计,模型库的组织与存储,以及所采用的数据挖掘方法等关键技术.本文所设计的库存决策支持系统适用于大型制造型企业,有助于提高供应链环境下企业的库存管理水平.     

Just-in-time purchasing: an integrated inventory model involving deterministic variable lead time and quality improvement investment

Nowadays supply chain management is a popular practice in manufacturing systems, and just-in-time (JIT) production plays a crucial role in supply chain environments. Companies are using JIT production to gain and maintain a competitive advantage. The characteristics of JIT systems are consistent high quality, small lot sizes, frequent delivery, short lead time, and close supplier ties. This paper presents an integrated inventory model to minimize the sum of the ordering/setup cost, holding cost, quality improvement investment and crashing cost by simultaneously optimizing the order quantity, lead time, process quality and number of deliveries while the probability distribution of the lead time demand is normal. This integrated inventory model is useful particularly for JIT inventory systems where the vendor and the purchaser form a strategic alliance for profit sharing.     

美国汽车业的供应链策略分析——互联网的影响

互联网的建立 ,实现了大量的信息流动 ,因而使供应链的本质起了极大的变化。汽车制造商为取得竞争优势 ,需要对其战略重新定位。为了得到更大的市场 ,公司必须做到以下两点 :一是缩短产品生产周期 ;二是缩短产品开发周期。为了降低成本 ,公司必须降低整条价值链中每一个环节的成本。商家通过互联网向顾客销售汽车及零部件 ,使得商家在配送和零售的模式上发生了很大的变化。这一变化不仅向公司提供了更好的市场透明度 ,更向消费者提供了直接挑选货品的机会。商家为顾客开启的大门还削减了传统销售中用于配送和零售的中介费用。本文的目的在于研究互联网中企业对企业的影响 ,以及今后应该如何置身于这一业务。供应商和汽车制造商应如何在互联网时代进行商业行为呢 ?本文的目的在于分析传统的 ,即以竞争和合作为特征的供应链关系的变化。我们将着眼于供应关系的改变、成本模式和样式转变等。本文结构如下 :第一节是对目前问题及其重要性的介绍 ;第二节主要讨论问题的一般表示形式 ,以及为取得战略竞争优势 ,解决问题的方法。第三节详细分析了汽车业的各个方面及其供应链。最后提出了企业的战略和结论。     

Comprehensive framework for the development of a supply chain strategy

Current competition among companies is fought through their supply chains. As the performance of the supply chain depends not only on manufacturing and marketing attributes, it becomes necessary to establish a framework upon which to develop a supply chain strategy. The paper presents the rationale and principles of a customer–product–process–resource (CPPR) framework for the simultaneous analysis of the business, supplier, manufacturing, planning, marketing and customer dimensions of a supply chain strategy. The originality of the CPPR framework is that it establishes a set of supply chain structural elements, that when put together determine the degree of alignment of a supply chain strategy. As the main objective of a supply chain strategy is to achieve customer satisfaction as an output of the supply chain operations, the CPPR framework becomes a realignment tool when used in combination with a realignment methodology, which is also presented in the paper.     

基于供应链管理的多周期合作型随机库存控制模型与仿真

在供应接管理的背景下，本文建立了一个具有不确定需求的多周期合作型供应链库存控制模型，并利用计算机仿真的方法对该模型进行了求解。     

The bullwhip effect on product orders and inventory: a perspective of demand forecasting techniques

Demand forecasting is one of the key causes of the bullwhip effect on product orders. Although this aspect of order oscillation is not ignored, the current study focuses on another critical aspect of oscillation: the bullwhip effect on inventory, i.e. the net inventory variance amplification. In particular, this paper studies a two-level supply chain in which the demand is price sensitive, while the price follows a first-order autoregressive pricing process. We derive the analytical expressions of the bullwhip effect on product orders and inventory using minimum mean-squared error, moving average and exponential smoothing forecasting techniques. We also propose the conditions under which the three forecasting techniques would be chosen by the retailer to minimise the sum of the bullwhip effect on product orders and inventory under different weightings. These observations are used to develop managerial insights regarding choosing an appropriate forecasting technique after considering certain distinct characteristics of the product.     

Lateral inventory transshipment problem in online-to-offline supply chain

Online-to-offline (OTO) is a new commercial model with enormous market potential. Online customer orders are forwarded to the offline brick-and-mortar store to fulfil, which is a combination of dual-channel supply chain. OTO overcomes many disadvantages of the traditional dual-channel supply chain, but still faces uncertain market demand. To reduce the inventory risk caused by demand uncertainty, lateral inventory transshipment is employed in this paper to pool inventory risk in OTO supply chain. We model centralised OTO and decentralised OTO with/without transshipment, and then analyse different scenarios. Our results demonstrate that there exists a unique Nash equilibrium of inventory order levels in dual channels and an optimal transshipment price to maximise the profit of the entire supply chain. Finally, we provide a numerical example of uniform demand distribution. Our analyses offer many managerial insights and show that transshipment always benefits the OTO supply chain.     

Lean,agile or leagile? Matching your supply chain to the marketplace

Many enterprises have pursued the lean thinking paradigm to improve the efficiency of their business processes. More recently, the agile manufacturing paradigm has been highlighted as an alternative to, and possibly an improvement on, leanness. In pursuing such arguments in isolation, the power of each paradigm may be lost, which is basically that agile manufacturing is adopted where demand is volatile, and lean manufacturing adopted where there is a stable demand. However, in some situations it is advisable to utilize a different paradigm on either side of the material flow de-coupling point to enable a total supply chain strategy. This approach we have termed the Leagile Paradigm. This paper therefore considers the effect of the marketplace environment on strategy selection to ensure optimal supply chain performance. Real-world case studies in the mechanical precision products, carpet making, and electronic products market sectors demonstrate the new approach to matching supply chain design to the actual needs of the marketplace.     

A semantic e-Kanban system for network-centric manufacturing: technology,scale-free convergence,value and cost-sharing considerations

It is critical to facilitate business partners to be seamlessly interoperable with each other as the network-centric manufacturing (NCM) paradigm becomes a major trend in today's manufacturing environment. In this work, we propose a semantic e-Kanban inventory system where a semantic gateway is acting as a mapping hub to enable heterogeneous messages to be seamlessly exchanged between business partners on demand. The semantic gateway uses reasoning rules to map business partners’ proprietary data schemas and provides interoperability required for NCM. To observe the network dynamics of our proposed system, a discrete time dynamic model is built and shows its growth to a scale-free network with a convergence rate depending on the initial connectivity of the semantic gateway and preferential attachment parameters. To analyse the proposed system from an economic perspective, analytical and numerical studies are conducted showing that it has enough potential to reduce supply chain costs in comparison to those of the traditional approach. Finally, this study attempts to address the cost-sharing issue encountered when multiple partners are direct beneficiaries of the efficiency gain through a joint network-centric capability, but it is questionable who should pay for the capability implementation. The cost-sharing issue must be investigated because most network-centric capabilities would not be economically or technically feasible for an individual company to achieve.