1. Analysis of Multi-objective Decision Problems in Humanitarian Supply Chains
    • Takeo Kobayashi
    • Yacob Khojasteh
    • Yasutaka Kainuma
    In humanitarian supply chains, there is a need to consider how to distribute the limited relief supplies that have not been prepared sufficiently to each shelter. Different from commercial supply chains that prioritize cost reduction, in humanitarian supply chains, it is important to consider not only reducing the distribution cost but also how to deliver goods quickly to satisfy the demands of shelters. Three metrics have been proposed for humanitarian supply chains: efficiency, equity, and efficacy. The objective of this paper is to define the metric of efficacy to minimize distribution time to each shelter considering the relief goods arrival. Under the situation after the disaster, to supply relief goods agilely and fairly, it is necessary to take account the weight of each metric adequately. We formulate a multi-objective mathematical model by the multiple metrics and carry out the optimization by using the model. The results show that the proposed multi-objective model is very promising in dealing with complicated humanitarian supply chains. Additionally, we show the deviation between the result of each metric and the multi-objective evaluation.
    @article{takeokobayashi-2019-1443,
      title={Analysis of Multi-objective Decision Problems in    Humanitarian Supply Chains},
      author={Takeo  Kobayashi and Yacob  Khojasteh and Yasutaka  Kainuma},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={60--67},
      doi={10.31387/oscm0370223}
    }
    Takeo  Kobayashi, Yacob  Khojasteh, Yasutaka  Kainuma (2019). Analysis of Multi-objective Decision Problems in    Humanitarian Supply Chains. Operations and Supply Chain Management: An International Journal, 12(2), 60-67. https://doi.org/10.31387/oscm0370223

  2. A Shopping-path Length Estimation Using Markov-chain-based Shopper Dynamics Model
    • Shunichi Ohmori
    • Masao Ueda
    • Kazuho Yoshimoto
    We propose a framework of estimating shopping-path length, in which the floor is represented by the graph G(V,E) with a vertex set V and an arc set E and the shopping-path length is measured by the number of zones (vertices) shoppers visit. We used the Markov-chain to model the dynamics of distribution of shoppers on the vertecies in the graph. We derive the (discrete) probability distribution of shopping path length using the transition matrix in the Markov-chain, and derive the expected path length. We proposed the index called the improvement importance index to quantify how local changes in the transition probability affect the entire shopping path length. We have tested our framework to the test data from an industrial application and the estimated path-length is compared to the actual one. We have a result that the error of estimation is 0.2%.
    @article{shunichiohmori-2019-1444,
      title={A Shopping-path Length Estimation Using Markov-chain-based Shopper Dynamics Model},
      author={Shunichi  Ohmori and Masao  Ueda and Kazuho  Yoshimoto},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={68--73},
      doi={10.31387/oscm0370224}
    }
    Shunichi  Ohmori, Masao  Ueda, Kazuho  Yoshimoto (2019). A Shopping-path Length Estimation Using Markov-chain-based Shopper Dynamics Model. Operations and Supply Chain Management: An International Journal, 12(2), 68-73. https://doi.org/10.31387/oscm0370224

  3. An Evaluation of Order-picking Tour Efficiency in Two-block Warehouses
    • Ömer Öztürko?lu
    • Deniz Ho?er
    This study investigates the effects of critical operational and strategical decisions in order-picking warehouses on order pickers’ tour lengths. For this study, one of the most-commonly applied layouts in practice, called two-block layout with a central cross aisle, was considered. A full factorial experimental design and multiple-comparisons (Bonferroni t-tests) were applied to statistically determine the significance of various levels of storage policies, pick-list sizes, warehouse shape ratios, warehouse sizes and their all interactions on average tour length. The analysis showed that deeper storage areas were superior to wider areas in small- and medium-sized warehouses. Warehouse designs with a 1:1 width-to-depth shape ratio offered the most robust layouts. Within-storage aisle policy significantly reduced order-picking tour length and generally outperformed other storage policies.
    @article{ömeröztürko?lu-2019-1445,
      title={An Evaluation of Order-picking Tour Efficiency in Two-block Warehouses},
      author={Ömer  Öztürko?lu and Deniz  Ho?er},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={74--87},
      doi={10.31387/oscm0370225}
    }
    Ömer  Öztürko?lu, Deniz  Ho?er (2019). An Evaluation of Order-picking Tour Efficiency in Two-block Warehouses. Operations and Supply Chain Management: An International Journal, 12(2), 74-87. https://doi.org/10.31387/oscm0370225

  4. A Multi Echelon Location-Inventory Model with Lateral Transshipment
    • Mohammad Reza Gholamian
    • Mustafa Nasri
    In this research, a supply chain system consisting producer, distribution centers and retailers is modeled by considering lateral transshipment between distribution centers and also using echelon-based inventory system instead of independent inventory system. The model is developed in the form of mixed integer non-linear programming (MINLP) to minimize the total location, transportation, and inventory costs of the system. The model was solved using conic programming approach and validity was examined by comparing the developed model with the basic model (i.e. the model without the contributions) in several instances with different sizes of distributors and retailers. The results represent superiority of the developed model in computational time and objective value especially in medium and large-scale problems.
    @article{mohammadrezagholamian-2019-1446,
      title={A Multi Echelon Location-Inventory Model with Lateral Transshipment},
      author={Mohammad Reza  Gholamian and Mustafa  Nasri},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={88--99},
      doi={10.31387/oscm0370226}
    }
    Mohammad Reza  Gholamian, Mustafa  Nasri (2019). A Multi Echelon Location-Inventory Model with Lateral Transshipment. Operations and Supply Chain Management: An International Journal, 12(2), 88-99. https://doi.org/10.31387/oscm0370226

  5. Modelling Facility Location Problems in Emerging Markets: The Case of The Public Healthcare Sector in Morocco
    • Asmae El Mokrini
    • Youssef Boulaksil
    • Abdelaziz Berrado
    Locating facilities in an emerging market involves specific characteristics that are different from developed countries. The differences between these two settings suggest that facility location modelling can present substantially different challenges when applied to an emerging market as opposed to a developed country. In this study, we develop a variant of the set covering model that explicitly takes specific characteristics into consideration. The model has been constructed and validated based on a real-life case study concerning the Moroccan Ministry of Health which is currently considering the redesign of its supply chain of pharmaceutical products. Amongst the findings, this paper shows that road infrastructure and demand dispersion affect the strategic decision of facility locations.
    @article{asmaeelmokrini-2019-1447,
      title={Modelling Facility Location Problems in Emerging Markets: The Case of The Public Healthcare Sector in Morocco},
      author={Asmae El  Mokrini and Youssef  Boulaksil and Abdelaziz  Berrado},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={100--111},
      doi={10.31387/oscm0370227}
    }
    Asmae El  Mokrini, Youssef  Boulaksil, Abdelaziz  Berrado (2019). Modelling Facility Location Problems in Emerging Markets: The Case of The Public Healthcare Sector in Morocco. Operations and Supply Chain Management: An International Journal, 12(2), 100-111. https://doi.org/10.31387/oscm0370227

  6. The Influence of Shopping Path Length on Sales Growth and Its Variance
    • Shunichi Ohmori
    • Masao Ueda
    • Kazuho Yoshimoto
    We study the influence of shopping path length on the number of items purchased. It is a well known fact in in-store shopper marketing that the longer the travel distance, the more items purchased. We analyze a shopping path data of 556 shoppers collected at a retail store in an urban are in Tokyo, Japan. We observed the fact the longer the travel distance, the greater the variance of the number of items purchased as well as its average. To explain this fact, we proposed a probability model of sequential purchase decisions using the Bernoulli process. We can estimate the number of items purchased as the binomial distribution given the shopping path. In the case study, we show how this assumption can be justified by the data from a real store.
    @article{shunichiohmori-2019-1448,
      title={The Influence of Shopping Path Length on Sales Growth and Its Variance},
      author={Shunichi  Ohmori and Masao  Ueda and Kazuho  Yoshimoto},
      journal={Operations and Supply Chain Management: An International Journal},
      year={2019},
      volume={12},
      number={2},
      pages={112--117},
      doi={10.31387/oscm0370228}
    }
    Shunichi  Ohmori, Masao  Ueda, Kazuho  Yoshimoto (2019). The Influence of Shopping Path Length on Sales Growth and Its Variance. Operations and Supply Chain Management: An International Journal, 12(2), 112-117. https://doi.org/10.31387/oscm0370228