A fuzzy multi-objective programming approach for determination of resilient supply portfolio under supply failure risks

The main contribution of this paper is to develop a new decision tool that interprets strategies for determination of resilient supply portfolio under supply failure risks. The strategic decisions include the allocation of emergency capacities to be pre-positioned at backup suppliers, the output of which can be increased in the event of mitigating a shortage caused by another supplier's failure. The model contains three objective functions – minimising the total cost, minimising the net rejected items and minimising the net late deliveries – while satisfying capacity and minimum order quantity requirement constraints. A weighted additive fuzzy multi-objective model is proposed to simultaneously consider the imprecision of information and the relative importance of objectives for determining the allocation of order quantity and emergency capacity to each supplier. The application of the proposed model is illustrated using an example case of global supply chains with different supplier characteristics.     

Green supplier selection: a new genetic/immune strategy with industrial application

With the onset of the ‘climate change movement’, organisations are striving to include environmental criteria into the supplier selection process. This article hybridises a Green Data Envelopment Analysis (GDEA)-based approach with a new Genetic/Immune Strategy for Data Envelopment Analysis (GIS-DEA). A GIS-DEA approach provides a different view to solving multi-criteria decision making problems using data envelopment analysis (DEA) by considering DEA as a multi-objective optimisation problem with efficiency as one objective and proximity of solution to decision makers’ preferences as the other objective. The hybrid approach called GIS-GDEA is applied here to a well-known automobile spare parts manufacturer in India and the results presented. User validation developed based on specific set of criteria suggests that the supplier selection process with GIS-GDEA is more practical than other approaches in a current industrial scenario with multiple decision makers.     

Supplier evaluation and demand allocation among suppliers in a supply chain

This paper presents a hybrid algorithm that prioritizes the suppliers and then allocates the demand among the suppliers. The objective here is to maximize the total purchase value of the items taking into consideration budget constraint, demand condition, delivery lead-time and supplier capacity. Since the problem is multi-criteria decision making, we solve this problem by integrating the supplier rating with mixed linear integer programming method. The customer demand is allocated by using a hybrid algorithm based on the technique for order preference by similarity to ideal solution (TOPSIS) and the mixed linear integer programming (MILP) approaches. The effectiveness of the proposed algorithm is validated with computational results. Drawing to a case, a supplier S₃ is identified as the best supplier by using the TOPSIS method for demand allocation under no restrictions. On the contrary, under constrained scenario, supplier S₂ is selected as the best supplier by using the hybrid algorithm for demand allocation and maximum units are allocated to S₂.     

Een systeem van kostenbeheersende productieplanning

In this paper a system of cost-controlled production planning is described. This system considers all kinds of costs associated with a production in phases (e.g. production of units, production of subassemblies, assembly) which may be affected by the planning, such as set-up costs, costs of transport, control, inventories, capacity and changes in capacity.
The mathematical model leads to a linear or mixed discrete-linear programming problem whose solution gives for each time period considered the size of the capacities which should be used and of the series of different products which should be produced. Practical recommendations are given for obtaining a sufficiently satisfying solution.     

供应不确定下基于Supply-hub的供应商选择和库存协同决策

针对由供应商、Supply-hub和制造商组成的三级供应链的多产品供应商选择和库存协同问题,考虑供应商存在延迟交付风险、供应数量约束,以供应链运作成本最小为目标,构建整数规划模型。分析结果表明:在一定的条件下,总存在最优的供应商选择方案和库存策略;当供应商的延迟交付概率增加,供应链期望成本上涨;当供应商供应数量无限制时,减少最优订货批量可以弱化供应不确定性增加造成的影响;当供应商选择方案不变,订货提前期增加,供应链的运作成本以及最优订货批量不变;一种零部件提前期的变化不影响其他零部件的供应商选择和库存策略。     

基于TOPSIS模型的火力发电企业电煤供应商选择评价研究

针对火力发电企业电煤供应商的特点,从成本因素、质量因素、到货因素三个方面,建立了由入厂标准煤单价、收到基恒容低位发热量、空气干燥基灰分、全水分、全硫、合格率、准时交货率、实收重量率8个指标构成的指标体系。采用了层次分析法确定的主观权重、熵权法确定客观权重,得到主观权重和客观权重相结合的组合权重,并使用TOPSIS模型对某火力发电企业的19个电煤供应商做出了评价和选择,对电煤供应商怎样提高竞争力以及火力发电企业对电煤供应商进行管理的重点内容提出了建议。     

基于OWA算子的供应商选择模型研究

目前,基于AHP法构建的供应商选择模型中,均未考虑实际决策时通常有多人参与,并且决策者会给出不同形式评价信息的情况。针对这一问题,将供应商选择视为一种不同形式偏好信息并存的群决策问题,结合AHP法,提出基于OWA算子的供应商选择模型。     

群体决策复合准则在供应商选择中的应用

供应商多属性的本质是供应商选择问题复杂性的主要原因之一,特别是属性为描述性质的模糊数时,有限理性的个体在决策制定过程中受到很大的局限。实际操作过程中,专家评分法运用广泛,在此基础上,文中将其与群决策理论相结合,首先指出了对供应商进行评价时常出现的平局问题,将群体决策复合准则引入到供应商选择过程中,然后建立模型,对其求解,最后结合算例,说明该方法的有效性。     

Supplier evaluation in the context of circular economy: A forward step for resilient business and environment concern

Resource depletion is a concern for the global economy; many think that available resources on the planet will not be able to cater to an ever-growing population. Thus, economies are trying to become circular, leaving behind the linear tradition linear approach. In the circular economy (CE), physical resources and energy are made to loop back into the supply chain (SC) for a more extended period. Proper selection of suppliers is an essential criterion towards proper execution of the CE principle in SC. In this research, we have constructed a framework for evaluating the supplier concerning the CE implementation. Further, this research identifies the criterion and sub-criterion, which are pertinent for evaluating the supplier in CE context. Fuzzy-based ‘Criteria Importance Through Inter-Criteria Correlation (CRITIC)’ method is justifiably applied to determine the aggregated weights of the criteria. Finally, ‘Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS)’ method is used to determine the suppliers' ranking in the Indian automobile industry. Six criteria and 24 sub-criteria are obtained as per recent literature and then inputs from experts. ‘Environment’ criterion came out as the most favourable criterion with a subjective weight of 0.230. The current research is one of the first such attempts to provide criteria for supplier selection in a CE environment. The developed framework would help organisations in implementing CE-based supplier selection. The identified criteria and sub-criteria would provide organisations with means to evaluate suppliers and help suppliers develop an effective and efficient CE based on the SC.     

Multivariate subset autoregressive modelling with zero constraints for detecting ‘overall causality’

The necessary and sufficient condition to test for ‘overall causality’, i.e., the presence of Granger- causality and instantaneous causal relations, in a bivariate and trivariate autoregressive model with recursive form is discussed. It is argued that the conventional AR model (the reduced form AR) is a more straightforward and effective means of testing for ‘overall causality’. To detect instanta- neous causality it is proposed to select the best subset system in a residual regression system in conjunction with model selection criteria. The Canadian money-income-bank rate system is re-examined in this way and by using a previously proposed algorithm we identify the optimum multivariate subset AR with constraints to detect whether there is ‘overall causality’ in that system.     

A pragmatic decision model for inventory management with heterogeneous suppliers

For enterprises, it is imperative that the trade-off between the cost of inventory and risk implications is managed in the most efficient manner. To explore this, we use the common example of a wholesaler operating in an environment where suppliers demonstrate heterogeneous reliability. The wholesaler has partial orders with dual suppliers and uses lateral transshipments. While supplier reliability is a key concern in inventory management, reliable suppliers are more expensive and investment in strategic approaches that improve supplier performance carries a high cost. Here we consider the operational strategy of dual sourcing with reliable and unreliable suppliers and model the total inventory cost where the likely scenario lead-time of the unreliable suppliers extends beyond the scheduling period. We then develop a Customized Integer Programming Optimization Model to determine the optimum size of partial orders with multiple suppliers. In addition to the objective of total cost optimization, this study takes into account the volatility of the cost associated with the uncertainty of an inventory system.     

What is required for greener supplier selection? A literature review and conceptual model development

This paper examines the existing literature on green supplier selection. In total, 60 articles are reviewed, all published in peer-reviewed journals between 1991 and 2011. The articles are analyzed in terms of several general variables such as type of research and theoretical viewpoint, as well as more specific variables such as the supply chain position considered, stages of the supplier selection process studied, and the perspective taken on environmental criteria. The main findings are threefold. First, analytical research, focusing on developing normative decision models for the final stage in green supplier selection is clearly most dominant, employing a wide range of techniques. Second, empirical research is less prominent and generally lacks a clear theoretical background. Third, very little conceptual research has been done linking green supplier selection to an organization's strategy. Research on green supplier selection is highly fragmented and in danger of overemphasizing the technical aspects of supplier selection. Based on this review of the articles, a conceptual model of green supplier selection is presented, aimed at integrating the different dimensions of green supplier selection and identifying directions for future research.     

基于多粒度二元语义的供应商选择方法

供应商选择是一个多属性决策问题,既包括定性的因素也包括定量的因素。把成本、质量、服务水平、供应商的能力和外部因素作为供应商选择的标准,并将基于多粒度二元语义信息处理的群决策方法应用于供应商的选择,给出了基于二元语义信息处理的群决策的步骤,最后给出了一个算例。     

排污权交易条件下缺陷产品生产库存策略研究

自二十世纪初以来,生产库存控制理论一直是运筹学研究中的重要领域。生产库存控制研究使用量化方法建立生产库存模型,给出最生产优库存控制策略。本文建立了排污权条件下易存在缺陷产品的生产库存模型,并对模型的解及其性质进行了分析,给出了基于排污权交易的缺陷产品的生产库存最优控制策略。     

Purchasing practices in small- to medium-sized enterprises: An examination of strategic purchasing adoption,supplier evaluation and supplier capabilities

The benefits that can be derived from effective purchasing have long been recognised in the management literature. Despite a growing body of research on purchasing practices in small- to medium-sized enterprises (SMEs), a number of key issues remain under-examined. We investigate SME purchasing practices in terms of (1) the degree to which purchasing is regarded as a ‘strategic’ activity by SMEs, (2) the use of supplier evaluation systems by SMEs and (3) the supplier capabilities emphasised by SME buyers. Through a survey of UK SME managers, we find that purchasing practices varied greatly across SMEs. Purchasing formality is generally low with limited evidence of purchasing being employed strategically and with many firms not undertaking formal supplier evaluations. In terms of supplier capabilities, we find that SMEs differ in the capabilities they prioritise, with three distinct groups evident. These groups are labelled ‘holistic’, ‘process’ and ‘logistics’ based on the supplier capabilities they emphasise. These three groups of firms also differed in terms of the emphasis they placed on strategic purchasing, supplier evaluation, technological focus and how they compete in their main markets, but not in terms of firm size or number of suppliers utilised. The implications of these findings are discussed and areas meriting future research are proposed.     

一种允许缺货的易变质产品的多级库存管理模型

本文提出了一个供应商、一个制造商和一个零售商在考虑产品变质且允许缺货情况下的供应链多级库存管理模型,通过算例用matlab6.5求出了其最优解,并通过灵敏度分析讨论了缺货率和供应链各级产品变质率对总成本的影响.     

A heuristic solution procedure for the multi-item,single-level,limited capacity,lot-sizing problem

The problem to be considered is that of determining lot-sizes for a group of products which are produced at a single workcentre. It is assumed that the requirements for each product are known, period by period, out to the end of some common time horizon. (A reasonable assumption in a Material Requirements Planning context when we are dealing with components of one or more other items already scheduled.) For each product there is a fixed setup cost incurred each time production takes place. Unit production and holding costs are linear. The time required to set up the machine is assumed to be negligible. All costs and production rates can vary from product to product but not with respect to time. In each period there is a finite amount of machine time available that can vary from period to period. The objective is to determine lot-sizes so that 1) costs are minimized, 2) no backlogging occurs and 3) capacity is not exceeded.An exact solution to this complex problem is out of the question. Therefore, a simple heuristic has been developed which guarantees a feasible solution, if one exists. Results of a large number of test problems, including three supplied by industrial sources, are presented. The results indicate that the heuristic will usually generate a very good solution with a relatively small amount of computational effort.     

Structural model for analysis of key performance indicators for sustainable manufacturer–supplier collaboration: A grey-decision-making trial and evaluation laboratory-based approach

With growing competition in the market and dire need for sustainability, it has become imperative for companies to build long-term relationship with their supply chain partners through sustainable collaboration. Among these, the supplier–manufacturer relationship is crucial for improved organizational, business and sustainable performance. Sustainable collaboration with suppliers involves crucial decision-making processes such as continuous supplier monitoring and supplier development. Hence, a critical challenge that a company faces is to identify the key performance indicators (KPIs) for assessing the performance of a supplier for sustainable collaboration. In this regard, this study focuses on identification of KPIs for an Indian home appliance company through exhaustive discussions involving multiple decision-makers. Further, a grey-based decision-making trial and evaluation laboratory (DEMATEL) model is proposed in the study for analysing the importance levels among the fifteen KPIs based on multiple stakeholder perspectives. The results of the grey structural model indicate seven KPIs as influencing KPIs and eight KPIs as influenced KPIs. The KPI ‘Information disclosure’ has been identified as the most influential KPI for the evaluation of suppliers for sustainable collaboration. The implications drawn from the result analysis model can provide meaningful insights to managers for identifying strategies towards strengthening the supplier–manufacturer relationship and achieving organizational and market competence.     

电网物资供应商的评价与选择及其软件设计

文章介绍了电网物资供应商评价的指标体系设计原则，并对其评价与选择的方法进行了确定后，通过分析建立了适合电网经营企业的物资供应商评价体系，对其供应商评价与选择的计算步骤进行了说明，同时讨论了层次分析法的软件系统设计，给出了框图。     

Strategic investment and international outsourcing in unionised oligopoly

We develop an oligopoly model in which firms facing unionised domestic labour markets choose between producing an intermediate good in-house and outsourcing it to a non-unionised foreign supplier that makes a relationship-specific investment in developing the intermediate. The paper sheds light on the issue of whether international outsourcing offers a means to ‘escape’ the power of domestic unions and on the existence of intra-industry wage dispersion. We show that outsourcing typically increases marginal costs even when it lowers union wages. Despite this, more powerful unions increase the incentive to outsource.