European J. of Industrial Engineering (9 papers in press)
The impact of online sales in centralized and decentralized dual-channel supply chains
by Subrata Saha
Abstract: This paper studies a supply chain structure featuring two different types of distribution channels through which manufacturers sell products. The centralised and decentralised distribution channels considered in this study are affected by online sales outside the structured channels. In the centralised distribution channel, two retail stores located in geographically distinct markets are operated by a single owner. In the decentralised distribution channel, two retailers independently operate two retail stores. In the non-cooperative scenario, the manufacturer always prefers the decentralised distribution channel irrespective of whether an online channel is used. To achieve channel coordination, a revenue-sharing contract is applied, but it can be used to coordinate only the decentralised distribution system. Therefore, a modified revenue-sharing contract is proposed to coordinate the centralised distribution system. The analytical study reveals that without coordination among the channel members, the manufacturer always earns maximum profit in decentralised distribution systems. However, if the supply chain is coordinated, then the manufacturer receives more benefits from using the centralised distribution systems under certain conditions. Propositions are presented to describe the characteristics of distribution structures, and to provide meaningful management guidelines for coordinating them. Extensive numerical investigations are also presented.
Keywords: Supply chain management; Dual-channel supply chain; Revenue sharing contract; Pricing strategy; Stackelberg.
Human-machine cooperation in planning and scheduling: a case study on an unstable environment
by Zakaria YAHOUNI, Nasser MEBARKI, Farouk BELKADI, Atif SHAHZAD, Alain BERNARD
Abstract: In an industrial environment, manufacturing systems may be subject to considerable uncertainties which may lead to numerous schedule disturbances. These disturbances prevent the execution of the planned production schedule. Groups of permutable jobs is one of the most studied methods that deal with this drawback. It constructs a flexible solution characterized by a set of schedules, allowing a human operator to execute, in real-time, the schedule that best fits the state of the shop. However, because of the limited complexity that one human being can handle, he/she needs to cooperate with the machine in order to take efficient decisions. This paper focuses on investigating the human-machine cooperation for planning and scheduling.AnewHuman-Machine Interface model assisted with a multi-indicator Decision Support System has been proposed and evaluated. The results show the usefulness/limits of the proposed model and provide insights into the practice of production planning and scheduling.
Keywords: Scheduling; Human-machine Interface; Decision support system; Flow shop.
Channel Selection for Automotive Parts Remanufacturer under Government Replacement-subsidy
by Sun Jianan, Xiao Zhongdong
Abstract: This paper considered government replacement-subsidy policy to examine the channel selection of the automotive parts remanufacturer, and we constructed two channel models in which the automotive parts remanufacturer may choose the supplier mode or competitor mode. Due to the relatively low acceptance of remanufactured automotive parts in developing countries such as China, we model the two scenarios with government offering replacement-subsidy to the remanufacturer to incentivize automotive parts remanufacturing activities. Then, we discuss the impacts of the replacement-subsidy policy on the strategy of channel selection by applying a game theory method. We find that the scope of the automotive parts remanufacturers net cost is quite vital, which is decided by the government replacement price, subsidy and costs of the remanufacturer. The subsidy and replacement price to customers have an affirmative influence on the protection of the environment within a specific range..
Keywords: automotive parts remanufacturing; replacement; government subsidy; channel selection.
Impact of pricing and inventory policies with benefit sharing mechanism on supply chain performances
by Chatdanai Kaorapapong, Pisal Yenradee
Abstract: This paper is to analyse impacts of pricing policies, inventory policies, and benefit sharing mechanism on supply chain (SC) performances. The novelties and theoretical contributions of this paper include a development of linear mathematical functions to represent pricing policies, especially every day low price, and explicitly considering cash as one of the performance measures in addition to profit and revenue. A mix integer linear programing model (MILP) with pricing mechanism and policy constraints is developed. A case study in plastic fashion accessary industry in Thailand is performed. Experiments are conducted to demonstrate how the proposed model is applied. The performance measures are translated into satisfaction levels and plotted in a radar chart to facilitate performance comparison among policies. Practical contribution is that this paper recommends suitable combinations of policies to match with the priority of profit, revenue, and cash performances.
Keywords: pricing policy; inventory policy; benefit sharing mechanism; supply chain planning; MILP.
Examination timetabling problem with scarce resources: a case study
by Muhammed Emre Keskin, Alper Döyen, Hasan Akyer, Mehmet Güray Güler
Abstract: Examination timetabling problem (ETP) is one of the hardest administrative tasks that has to be undertaken several times at each semester in all faculties. Although the major structure of the problem remains intact, requirements may change from faculty to faculty causing major changes in the solution procedures. The number of academic staff and the level of infrastructures of newly established universities cannot keep up with the increasing number of departments and students in Turkey. This scarcity brings several additional constraints to the ETP. In this study, we propose a two stage solution procedure for the ETP of such universities.We apply our solution method to a real problem, in particular to the final exam scheduling problem of Faculty of Engineering at Pamukkale University.We showthat better feasible solutions can be found in shorter computation times by our method than the feasible solutions found by commercial softwares. Moreover we show that the total examination period length can be reduced from 7 days to 6 days with the proposed method.
Keywords: Examination Timetabling; Mixed-Integer Programming; Decomposition; Heuristic.
Flowshop Sequence-dependent Group Scheduling with Minimization of Weighted Earliness and Tardiness
by Taha Keshavarz, Nasser Salmasi, Mohsen Varmazyar
Abstract: In this research, we approach the flowshop sequence-dependent group scheduling problem with minimization of total weighted earliness and tardiness as the objective for the first time. A mixed integer linear programing model is developed to solve the problem optimally. Since the proposed research problem is proven to be NP-hard, a hybrid meta-heuristic algorithm based on the particle swarm optimization (PSO) algorithm, enhanced with neighborhood search is developed to heuristically solve the problem. Since the objective is a non-regular, a timing algorithm is developed to find the best schedule for each sequence provided by the metaheuristic algorithm. A lower bounding method is also developed by reformulating the problem as a Dantzig-Wolf decomposition model to evaluate the performance of the proposed PSO algorithm. The computational results, based on using available test problems in the literature, demonstrate that the proposed PSO algorithm and the lower bounding method are quite effective, especially in the instances with loose due date.
Keywords: Earliness and tardiness; Sequence-dependent setup time; Group scheduling; Dantzig-Wolf decomposition; Particle swarm optimization.
An adaptive large neighborhood search-based optimization for economic co-scheduling of mobile robots
by Bing-Hai Zhou, Jia-Hui Xu
Abstract: The growing energy consumption and environmental pressures call for economic and friendly green manufacturing. The paper creatively studies an economic part feeding scheduling problem with a cooperative mechanism to coordinate multiple mobile robots in the fullest sense. When solving the economic co-scheduling problem in mixed-model assembly lines, this paper jointly considers the objective of energy saving as well as the robot employment cost, which incorporates traditional performance criterion with growing energy concerns. In order to improve the performance and diversity of solutions, A multi-phase adaptive search (MPAS) algorithm is proposed which is integrated with clustering heuristics, specific destroy and repair rules, adaptive selection and perturbation strategy. Computational experiments are conducted in order to test and verify the effectiveness and efficiency of the proposed MPAS algorithm. Comparison tests are carried out between the proposed MPAS and two widely-applied benchmark algorithms. The results obtained in this study might be inspiring for future studies on energy-efficient cooperative scheduling topics.
Keywords: mobile robots; line-integrated supermarkets; energy consumption;
Supply Chains Competition with Vertical and Horizontal Information Sharing
by Zhaobo Chen, Chunying Tian, Ding Zhang
Abstract: This paper studies the incentive for vertical and horizontal information sharing in two competing supply chains with uncertain demand. Retailers obtain the uncertain demand information from the market, and can exchange the private information with each other. We investigate the equilibrium information sharing arrangement in the competing supply chains and discuss how expected payoffs of the firms and the supply chains is impacted by horizontal information sharing. The results show that no vertical information sharing in both supply chains is the unique equilibrium in one-shot game, and horizontal information sharing wont affect the vertical information sharing strategy for the competing supply chains. However, horizontal information sharing will increase the supply chain profits if the competition between two supply chains is sufficiently less intense. Furthermore, we analyse the conditions of prisoners dilemma for the equilibrium information sharing arrangement and the perfect Nash equilibrium of the repeated game.
Keywords: supply chain management; supply chain competition; information sharing.
Scheduling TV advertisements via genetic algorithm
by Kateryna Czerniachowska
Abstract: Television Advertising is vital to the television industry, and is one of the most popular ways for advertisers to increase sales. This paper discusses the problem of scheduling TV advertisements according to each advertisers needs and budget limitations, with the objective of maximizing total viewership. The proposed solution is the genetic algorithm, and its efficiency has been evaluated using list and random-list algorithms during long (1 month) and short (1 week) advertising campaign periods. Computational results show that this algorithm can obtain satisfactory results for real-world test problems, based on data from a marketing research company
Keywords: scheduling; media planning; advertising; genetic algorithm; heuristics.