Browsing by Author "Tuna, Okan"

Now showing 1 - 4 of 4

Current State and Future of Shipping and Logistics
(Elsevier Science Bv, 2013) Tuna, Okan; Duru, Okan
Greening Logistics Centers: The Evolution of Industrial Buying Criteria Towards Green
(Elsevier Science Bv, 2013) Altuntas, Ceren; Tuna, Okan
The rapidly globalizing world trade requires longer supply chains with higher attention on the environmental effects of logistics activities. Latest international conventions related with environmental regulations reinforce governments and corporations to adhere to environmental protection precautions. An effort to decrease the negative environmental effects of logistics activity is the geographical concentration of logistics companies which are called logistics centers. This study aims to provide a green industrial service buying approach for the industrial customers of logistics centers. The study combines green purchasing literature with previousely developed environmental performance indicators (EPIs) and develops a green industrial buying model for logistics centers. The model provides a framework for potential residents of a logistics center and supports their industrial buying processes. The model also serves as an input for green industrial service design in a logistics center.
A New Simulation Modelling Approach to Continuous Berth Allocation
(Taylor & Francis Ltd, 2013) Esmer, Soner; Yildiz, Gokalp; Tuna, Okan
Within the international supply chain and logistics system, ports are an important ring of the basic transport activities. Thus, any shortage in or lack of well-planned orders encountered in the port operation processes is most likely to affect the whole logistic system, which eventually will cause undesirable delays in deliveries. This study aims at developing a simulation modelling approach to continuous berth allocation in Port of Izmir Alsancak, which has continuous quayside with two main wharfs perpendicular to each other. The simulation models which serve to evaluate the proposed modelling approach have been developed in ARENA 10.0 Simulation Software. The results of the conducted computational experiments showed that the proposed modelling approach provides more accurate and realistic estimates of performance measures, such as average berth utilisation, average ship waiting time in a queue, and the average number of ships in queuing up to get container terminals.
The Prioritisation of Service Dimensions in Logistics Centres: A Fuzzy Quality Function Deployment Methodology
(Taylor & Francis Ltd, 2016) Vural, Ceren Altuntas; Tuna, Okan
This study takes a customer focus that prioritises the service-offering dimensions of logistics centres (LCs) by considering potential LC customer expectations. Applying a survey and a quality function deployment methodology to logistics service providers, the study explores, categorises and prioritises LC customer expectations and LC service characteristics. The results indicate that customer preferences mainly prioritise infrastructure, and warehouse and intermodal dimensions. However, when the cost dimension is included, higher utility values are delivered through soft service dimensions like value-added or standard services. LC investors or undertakers can use these results to guide their design of market offerings by using the same methodology to assess expectations in their target markets.