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Klasik akış tipi çizelgeleme problemi, birbiri ardına sıralanmış makinelerin bulunduğu ve her iş için aynı makine sırasının takip edilmesi prensibine dayalıdır. İş ve makine sayılarının artmasıyla akış tipi çizelgeleme problemleri çok karmaşık hale dönüşmektedir. Bu karmaşık problemleri çözmek üzere birçok meta sezgisel yöntem kullanılmaktadır. Meta sezgisel yöntemlerle optimum çözüm aranırken başlangıç popülasyonlarının etkisi çok büyük önem arz etmektedir. Bu çalışmada hibrit ateşböceği parçacık sürü optimizasyonu algoritması kullanılarak literatürdeki akış tipi çizelgeleme problemlerinde, farklı başlangıç popülasyonlarının etkisinin gözlemlenmesi amaçlanmaktadır. Bu amaçla beş farklı başlangıç popülasyonu oluşturma yöntemi ele alınarak, karşılaştırma testleri yapılmıştır. Nawaz-Enscore-Ham algoritmasını içeren yöntemlerin ortalama göreli sapma değerlerinin daha iyi olduğu belirlenmiştir. Nawaz-Enscore-Ham algoritmasının farklı parçacık sayısı düzeyleri için başarısı test edilmiş ve sonuçlar sunulmuştur.The classical flow shop scheduling problem is based on the principle that the machines are sequenced sequentially and that the same machine sequence is followed for each job. The flow shop scheduling problems become very complex, with the increase in the number of jobs and machines. Many meta-heuristic methods are used to solve these complex problems. The effect of initial populations has great importance for searching optimal solutions by meta-heuristics methods. In this study, it is aimed to observe the effect of different initial populations in flow shop scheduling problems in the literature by using hybrid firefly particle swarm optimization algorithm. For this purpose, 5 different initial population generation methods were set and comparison tests were performed. The mean relative deviation values of the methods including the Nawaz-Enscore-Ham algorithm were determined to be better. The success of the Nawaz-Enscore-Ham algorithm for different particle count levels has been tested and the results are presented.Anahtar kelimeler: Akış tipi çizelgeleme, Meta sezgisel yöntemler, Hibrit ateşböceği parçacık sürü optimizasyonu, Başlangıç popülasyonu, NEH

One of the most active sectors in an increasingly globalized world, retail sector has become a rapidly developing sector in Turkey as well. Companies in this sector must follow an inventory policy that provides them with minimum cost and maximum profit in order to compete and survive in market. For this reason, effective management of inventory is crucially important in the retail sector, as in other sectors. In this study, Six Sigma method was used in order to reduce the inventory levels in a large supermarket operating both wholesale and retail in Turkey. Six Sigma is a management tool that emphasizes continuous improvement as a culture and increases the efficiency of processes. In this study, the causes of high inventory levels were determined by following the steps of the Six Sigma method, and the collected data were analyzed. At the end of the implementation, some improvement actions were planned to reduce inventory levels, and a monitoring system was established to ensure sustainability. There was a deficiency in inventory tracking and demand forecasting processes. The main reason for this was seen to be the purchasing organization. It was determined that sometimes more than necessary purchases were made. Six sigma studies on supermarkets in Turkey are limited. This study sets an example for the use of the Six Sigma method, which is a systematic process improvement method for the retail industry.