Optimal collection and remanufacturing decisions in reverse supply chains with collector’s imperfect sorting

We consider a reverse supply chain comprising two independent companies: the collector and the remanufacturer. The collector is responsible for sorting the collected used products and then transporting the ‘remanufacturable’ items to the remanufacturer. As sorting is not perfectly accurate, the misclassification errors affect the optimal decisions in the reverse supply chain. We focus on the optimal collection quantity for the collector and the optimal order quantity for the remanufacturer using game theory under both deterministic and uncertain demand. We characterise the optimal solution and show that under certain conditions, the remanufacturer should allow the collector to transport more ‘remanufacturables’ than the order quantity. We then examine the case where both the collector and the remanufacturer belong to a single company with centralised decision-making and compare the optimal collection quantities under both structures of the reverse supply chain.     

Dynamic optimisation for highly agile supply chains in e-procurement context

In the conditions of an increased worldwide competition, supply chains are struggling to respond to an increasingly volatile and complex environment. With technological advances, current practices to build efficient supply chains have changed. Companies are seeking to use internet in order to cope with the flexible and dynamic nature of logistics networks. The purpose of this article is to address the flexible dynamic e-procurement context under asynchronous and repetitive variations over time. The supply chain considered is composed of two levels (buyer–suppliers) operating in highly agile environment. The questions facing the buyer is how many units of product should be purchased and from which supplier in response to variation in term of price and capacity. Because of this highly changing environment characterised by frequent changes in a short time, most of the classical optimisation approaches seem inadequate to address these problems. Recently, dynamic optimisation has been proposed to deal with such problems. However, we have no knowledge of its application in a supply chain context. We suggest a dynamic genetic approach which is applied to an e-procurement context in aim to optimise the procurement process during time.     

A paler shade of green: implications of green product deletion on supply chains

Product management activities by operations, marketing, and finance functions have typically focused on the innovation, acquisition, growth, and management of product lines and products. The same is true when considering product management for green products. The latter stages of critical strategic decisions related to product deletion or discontinuation have received less emphasis. In this conceptual paper, the focus is on green product deletion implications for supply chain management and operations. Organisations may view green product deletion as evolving from a deep green to a paler shade of green in their product offerings. A proposed strategic framework pays particular attention to the implications of the green product deletion decision for supply chain processes and operational competencies. In this situation, lessened organisational greenness needs to be weighed against other organisational and operational competencies. The strategic and inter-organisational relationships associated with this decision help set the stage for future research on this critical, yet neglected, organisational and operational supply chain issue.     

Modelling and optimisation of biomass supply chains: a review

A growing number of researchers are attracted by the domain of bioenergies, due to the problems induced by greenhouse gas emissions and increasing energy demand. One possible way of producing biofuels in a renewable way is to use biomass, however the economic viability of a biorefinery system depends critically on the cost of its supplies. As biomass is not very expensive, logistics is responsible of an important fraction of this cost. Models and methods to optimise biomass supply chains are surveyed in this article, after introducing some technical terms and describing the main activities in these chains. This review aims to give a comprehensive overview of the research in this field with a focus on optimisation modelling issues and solution approaches. Recent advances in the current research and possible new directions are sketched.     

Dynamic buy-back for product recovery in end-of-life spare parts procurement

The efficient supply of spare parts is of prime concern for original equipment manufacturers (OEM). While manufacturing the parent product, spare parts can be sourced efficiently by using existing manufacturing facilities. This situation completely changes once the original equipment manufacturer ceases production of the parent product. In addition to traditional spare parts sources in the form of final order and remanufacturing, the option to buy back parts or products provides a viable alternative in the end-of-life phase. This can prevent the OEM from fulfilling his spare parts availability obligation or increase his ability to remanufacture. Current practice in industry is, on the one hand, to offer trade-in campaigns to acquire functional products from customers by giving substantial discounts on a new-generation product. On the other hand, trade-in rebates are given when customers return their broken parts in exchange for spare parts. We propose the consideration of a third option, i.e. to buy back broken products in order to improve control of both demand for spare parts and supply of recoverable parts. This contribution seeks to assess the potential benefit of buy-back strategies in contrast to both traditional sourcing and trade-in campaigns for different settings regarding information availability and buy-back flexibility. For each situation, a MILP formulation is presented, and in a numerical study we analyse the circumstances under which the buy-back of broken products is especially beneficial for the OEM.     

Dual-channel closed loop supply chains: forward channel competition,power structures and coordination

This paper examines the effect of forward channel competition and power structure on dual-channel closed loop supply chains (CLSC), which consists of a manufacturer, a retailer and a collector. The manufacturer can either wholesale products to the retailer or directly sell them to the market, the collector undertakes the collection activity of used products. Under different channel power structures, a centralised and three decentralised models are explored under symmetric and asymmetric relative status between direct and retail channels. Through a comprehensive comparison among these models, the result shows that each channel member has an incentive to play the channel leader’s role. Meanwhile, from the total channel system’s perspective, we find that the manufacturer-led or retailer-led model can either be the most effective CLSC under symmetric relative channel status, which depends on the channel substitution rate between two channels. While under asymmetric relative channel status, the numerical result shows that the whole CLSC should select collector-led, manufacturer-led and retailer-led CLSC model in turn with the retail channel’s relative status becoming stronger. Finally, with the benchmark of the centralised decision-making system, we design modified two-part tariff contracts to coordinate dual-channel CLSCs under different channel power structures.     

Optimal policies in hybrid manufacturing/remanufacturing systems with random price-sensitive product returns

We study a production planning problem in which a manufacturer aims to meet a random market demand by manufacturing new product and remanufacturing returned product. The product returns are random and price-sensitive. To maximise his profit, the manufacturer needs to optimally decide on the acquisition price for the returned product as well as the quantities of the new product to be manufactured and the returned product to be remanufactured. We investigate two cases based on the relative lengths of the manufacturing and remanufacturing lead times. (1) In the case with a shorter manufacturing lead time, the manufacturer first decides his acquisition price for the returned product before the production starts, and then decides the quantities of manufacturing/remanufacturing after the product returns are realised. (2) In the case with a shorter remanufacturing lead time, the manufacturer first decides the manufacturing quantity and the acquisition price simultaneously, and then the remanufacturing quantity based on the quantity of manufactured and returned products. Each case is formulated as a two-stage stochastic optimisation problem, and the corresponding optimal polices of both are characterised and derived.     

Empirical evaluation of the delivery risk of extended supply chains

The rise in global sourcing has led to extended supply chains. Extended supply chains generally have more mode changes, border crossings, rail classification yards, port congestion and so forth, that all lead to more delivery disruption risk. To test this assertion, we perform an empirical assessment of the inbound supply chain disruption risk at a major manufacturer that imports components from over three dozen different countries. Although delivery disruption risk can be mitigated with effort, we observe that delivery disruption risk increases with distance. Based on industrial data, we quantify the increase in delivery disruption with international versus domestic suppliers and intercontinental versus continental suppliers.     

Closed loop supply chain network design and optimisation using fuzzy mixed integer linear programming model

Owing to the revolution in sustainable and green manufacturing the production planning and network design of closed loop supply chain concept has got the attention of researchers and managers. In this paper, a multi-product, multi-facility capacitated closed-loop supply chain framework is proposed in an uncertain environment including reuse, refurbish, recycle and disposal of parts. The uncertainty related to demand, fraction of parts recovered for different product recovery processes, product acquisition cost, purchasing cost, transportation cost, processing, and set-up cost is handled with fuzzy numbers. A fuzzy mixed integer linear programming model is proposed to decide optimally the location and allocation of parts at each facility and number of parts to be purchased from external suppliers in order to maximise the profit of organisation. The proposed solution methodology is able to generate a balanced solution between the feasibility degree and degree of satisfaction of the decision maker. The proposed model has been tested with an illustrative example.     

A study on contractual agreements in supply chains of agricultural produce

Agricultural produce deteriorates in both quality and quantity over time, and how to determine appropriate operating and marketing strategies to reduce the loss from rottenness is essential in supply chains for such items. This study considers a two-echelon supply chain in which agricultural produce is provided by a grower to a wholesaler, and the harvest quantity for the grower may decrease due to unpredictable pest problems or weather factors. In addition, agricultural produce may be damaged during transportation and thus become inferior products with less value. The two different scenarios are considered in this study: with and without a contractual agreement, to develop the corresponding optimal pricing strategies for the grower and wholesaler. The results indicate that a contractual agreement by setting moderate ordering boundaries can achieve a win-win situation for both parties by mitigating the grower’s risk, since it can encourage the grower to plant more produce and thus ensure that the wholesaler can have enough produce to sell. Besides, in case that a low proportion of inferior products and a low discount rate can be managed, the use of contractual agreements would be beneficial for the grower. Moreover, the rise in the retailing prices of both the regular and inferior agricultural produce may collectively increase the total profit of the supply chain, but can actually hurt the wholesaler’s profit.     

Closed-loop supply chains of reusable articles: a typology grounded on case studies

Reuse practices contribute to the environmental and economical sustainability of production and distribution systems. Surprisingly, reuse closed-loop supply chains (CLSC) have not been widely researched for the moment. In this paper, we explore the scientific literature on reuse and we propose a definition for reusable articles and a typology integrating different categories of articles (transportation items, packaging materials, tools) under the term ‘reusable articles’. Our definition shows how reusable articles are different from other types of recovery, such as remanufacturing or recycling. We also point out specific research needs for those articles. We have based our results on a set of case studies developed in real industrial settings, which have also been contrasted with cases available in the existing literature.     

Sustainable supply chains for supply chain sustainability: impact of sustainability efforts on supply chain risk

Supply chain managers across the globe are finding it difficult to manage the increasingly complex supply chains despite adopting a variety of risk mitigation strategies. Firms on the other hand have also been adopting various kinds of environmental and social sustainability practices in recent times to reduce carbon footprint and improve their image on the social front. However, very few studies in the extant literature have examined the impact of sustainability practices on supply chain risk. We address this important gap in literature by empirically testing this relationship, using primary data from six manufacturing sectors and 21 different countries including developed as well as emerging markets across the globe. Our findings indicate that risk mitigation strategies do not always reduce the actual supply chain risk experienced by firms, whereas sustainability efforts help reduce supply chain risk, especially in emerging market contexts. In addition, we find that, while reactive risk mitigation strategies on their own fail to reduce supply chain risk, they are effective when used in conjunction with sustainability efforts. We also find that preventive risk mitigation efforts are only effective in mature supply chains such as the OECD countries.     

Available-to-promise-based flexible order allocation in ATO supply chains

This paper presents a new available-to-promise (ATP) based order allocation model, which is different from traditional order fulfilment systems in that it considers customer priority in an assemble-to-order (ATO) supply chain environment before the order is fulfilled. First, in terms of customer priority, a pre-allocated model is proposed in order to obtain reserving production capacity ATP and reserving components ATP for each customer class. Then, two order fulfilment models are formulated: the batch order fulfilment model for processing all orders during an order reception period and the real-time order fulfilment model for making order fulfilment decisions when an order arrives immediately. In case that the available production capacity and components are not enough, the ATP searching rules are developed along four dimensions (time dimension, customer demand priority level dimension, product dimension and selling area dimension). Finally, the proposed models are illustrated through an electronic product manufacturing case. The results of the case study show that the performance of the proposed order fulfilment system is better than that of the traditional one.     

Stochastic optimisation model for integrated decisions on relief supply chains: preparedness for disaster response

This paper proposes a stochastic linear mixed-integer programming model for integrated decisions in the preparedness and response stages in pre- and post-disaster operations, respectively. We develop a model for integrated decisions that considers three key areas of emergency logistics: facility and stock prepositioning, evacuation planning and relief vehicle planning. To develop a framework for effective relief operations, we consider not only a cost-based but also an equity-based solution approach in our multiple objectives model. Then a normalised weighted sum method is used to parameterise our multiple objective programming model. This paper suggests a compromise between the cost, and the equity of relief victims. The experiments also demonstrate how time restrictions and the availability of relief vehicles impact the two objective functions.     

Blockchain in global supply chains and cross border trade: a critical synthesis of the state-of-the-art,challenges and opportunities

Blockchain possesses the potential of transforming global supply chain management. Gartner predicts that blockchain could be able to track $2?T of goods and services in their movement across the globe by 2023, and blockchain will be a more than $3 trillion business by 2030. Nowadays, a growing number of blockchain initiatives are disrupting traditional business models in each sector. In this paper, we provide a timely and holistic overview of the state-of-the-art, challenges, gaps and opportunities in global supply chain and trade operations for both the private sector and governmental agencies, by synthesising a wide range of resources from business leaders, global international organisations, leading supply chain consulting firms, research articles, trade magazines and conferences. We then identify collaborative schema and future research directions for industry, government, and academia to jointly work together in ensuring that the full potential of blockchain is unleashed amidst the socioeconomic, geopolitical and technological disruptions that global supply chains and trade are facing.     

Incentives for quality improvement efforts coordination in supply chains with partial cost allocation contract

In this paper, we consider quality improvement efforts coordination in a two-stage decentralised supply chain with a partial cost allocation contract. The supply chain consists of one supplier and one manufacturer, both of which produce defective products. Two kinds of failure cost occur within the supply chain: internal and external. The supplier and the manufacturer determine their individual quality levels to maximise their own profits. We propose a partial cost allocation contract, under which the external failure cost is allocated between the manufacturer and the supplier at different rates based on information derived from failure root cause analysis. If the quality levels of the supplier and the manufacturer are observable, we show that the partial cost allocation contract coordinates the supply chain, provided that the failure root cause analysis does not erroneously identify the manufacturer’s fault as the supplier’s, and the supplier does not take responsibility for the manufacture’s fault. In the single moral hazard model, where only the quality level of the supplier is unobservable, the optimal share rates require the supplier to take some responsibility for the manufacture’s fault. However, in the double moral hazard model, where quality levels of the supplier and the manufacturer are unobservable to each other, the optimal share rates require the supplier not to take responsibility for the manufacturer’s fault. It is noted that the root cause analysis conducted by the manufacturer may have its disadvantage in attributing the fault to the supplier when both sides are at fault. We also propose a contract based on the dual root cause analysis to reduce the supplier’s penalty cost. Numerical results illustrate that the partial cost allocation contract satisfies the fairness criterion compared with the traditional cost allocation contract.     

An empirical investigation of antecedents to information exchange in supply chains

In this investigation, following the principal-agent theory, possibilities to reduce existing information asymmetries are derived and their effects on the information exchange are examined. Results of an empirical investigation based on a structural equation model confirm that monitoring measures and frequent meetings positively influence the exchange of information while explicit contracts have rather negative effects. Premiums and specific investments, however, seem to play insignificant roles. Measures, such as building a reputation mechanism, will probably prove to be effective only in the long run.     

A multi-agent architecture for reverse logistics in a green supply chain

Green supply chain issues have attracted a lot of attention in recent years with growing awareness of environmental concerns. This has drawn the considerable world-wide attention of academics and practitioners. Therefore, recycling has now become an integral component of the supply chain. Recycling of used products and the related logistics management pose a significant challenge to manufacturing industries. In order to resolve the complexity of the task, this study proposes a multi-agent architecture to handle recycling and reverse logistics issues, which have so far been neglected. It addresses the different aspects of recycling such as waste classification, recycling, logistics and reuse of products. Additionally, it also discusses how the agent communicates and acts autonomously to facilitate the efficient logistics of materials between different units. The proposed agent architecture can assist manufacturing industries in efficiently managing their green supply chain system and complex logistics issues.     

Analysis of closed loop supply chain using genetic algorithm and particle swarm optimisation

This paper describes a relational database system for semi-generative process planning for sheet metal parts that emulates expert system capabilities. The system integrates a feature-based relational database for the parts, a forward chaining rule-based strategy for machine selection, both global and feature-specific execution of the rules and a graph theoretic cost optimization model for optimal process plan selection. This system, which is currently being developed for a sheet metal fabrication company, suggests that, using the experience of shopfloor personnel, an efficient integration of feature-based process planning and expert system strategies can be accomplished.