Good practice proposal for the implementation, presentation, and comparison of metaheuristics for solving routing problems

Researchers who investigate in any area related to computational algorithms (both dening new algorithms or improving existing ones) usually nd large diculties to test their work. Comparisons among dierent researches in this eld are often a hard task, due to the ambiguity or lack of detail in the presentation of the work and its results. On many occasions, the replication of the work conducted by other researchers is required, which leads to a waste of time and a delay in the research advances. The authors of this study propose a procedure to introduce new techniques and their results in the eld of routing problems. In this paper this procedure is detailed, and a set of good practices to follow are deeply described. It is noteworthy that this procedure can be applied to any combinatorial optimization problem. Anyway, the literature of this study is focused on routing problems. This eld has been chosen because of its importance in real world, and its relevance in the actual literature

Coping with the Rise of E-commerce Generated Home Deliveries through Innovative Last-Mile Technologies and Strategies

Caltrans 65A0686 Task Order 066USDOT Grant 69A3551747114E-commerce can potentially make urban goods flow economically viable, environmentally efficient, and socially equitable. However, as e-retailers compete with increasingly consumer-focused services, urban freight witnesses a significant increase in associated distribution costs and negative externalities, particularly affecting those living close to logistics clusters. Hence, to remain competitive, e-retailers deploy alternate last-mile distribution strategies. These alternate strategies, such as those that include the use of electric delivery trucks for last-mile operations, a fleet of crowdsourced drivers for last-mile delivery, consolidation facilities coupled with light-duty delivery vehicles for a multi-echelon distribution, or collection-points for customer pickup, can restore sustainable urban goods flow. Thus, in this study, the authors investigate the opportunities and challenges associated with alternate last-mile distribution strategies for an e-retailer offering expedited service with rush delivery within strict timeframes. To this end, the authors formulate a last-mile network design (LMND) problem as a dynamic-stochastic two-echelon capacitated location routing problem with time-windows (DS-2E-C-LRP-TW) addressed with an adaptive large neighborhood search (ALNS) metaheuristic

Yeşil depo yeri belirleme ve araç rotalama problemlerinin GA ve sezgisel metotlarla çözülmesi : boya imalat firmasında uygulanması

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Yer seçimi ve rotalama problemleri, lojistik problemlerinin en önemli konularından olup farklı yaklaşımlarla ve çözüm yöntemleri ile geliştirilerek daha özel hale getirilmiş problemlerdir. Bu çalışmada verimlilik ve karlılık oranlarını arttırmak için bir boya firmasının lojistik biriminde, kara lojistiğinin en önemli problemlerinden olan depo yeri seçimi ve rotalama problemine farklı yaklaşımlarla çözümler aranmaktadır. İki farklı model önerilmiştir. İlk modelde şehirlerarası km'leri dikkate alarak çözüm yolu önerisi getirilmiştir. İkinci modelde ise çevreye karşı farkındalığı arttırmak için dünyada hızla artan küresel ısınmanın en önemli sebeplerinden olan sera gazlarından CO2 emisyon miktarlarını yolların eğimini dikkate alarak azaltan çözüm yolu önerisi getirilmiştir. Yer seçimi ve rotalama problemine, depo-yer seçimi ve atama problemi, kapasiteli araç rotalama problemi olmak üzere kademeli yaklaşım önerilmiştir. Birinci aşamada problem Mixed-Integer Linear Programming (MILP)'de çözülerek atama yapılmıştır. Sonuç olarak tüm şehirler uygun depolara tahsis edilmiştir. İkinci aşamada kapasiteli araç rotalama problemi sezgisel algoritma ve genetik algoritma yöntemleri kullanılarak çözülmüştür. Önerilen modeller Marmara Bölgesi'nde boya fabrikasında uygulanmıştır. Sonuç olarak önerilen genetik algoritmaların model 1 ve model 2'de klasik sezgisel yöntemden daha avantajlı olduğu sonucuna varılmıştır.Location and routing problems are one of the most important issues of logistics problems and solved using different approaches. In this study, location and routing problems were solved in a logistic department of a paint firm to increase the productivity and profitability rates. Two different models were proposed. The first model was only related with kms among cities. At the second model, in order to raise awareness on the environment, greenhouse gases that are one of the most important reasons of global warming in the world, was included into the model to reduce CO2 emissions by taking into account the inclination of roads. A hierarchical approach was proposed to solve these problems. At the first level, an assignment to problem (MILP) was solved. As a result, all the cities were assigned to proper storages. At the second level, capacitated routing problem was solved using a heuristic and genetic algorithm. The proposed models were applied in a real life paint factory, in Marmara region, Turkey. The results illustrate that the proposed genetic algorithm produced better result than the classical heuristic method for model 1 and model 2