Прегледај по Аутор "Vesković, Slavko"

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    A New Integrated Fuzzy Approach to Selecting the Best Solution for Business Balance of Passenger Rail Operator: Fuzzy PIPRECIA-Fuzzy EDAS Model
    (MDPI, 2020) Vesković, Slavko; Stević, Željko; Karabašević, Darjan; Rajilić, Snježana; Milinković, Sanjin; Stojić, Gordan
    The analysis of operations of the passenger traffic operator in the Republic of Srpska (RS) showed that the volume of passenger transport has, for the last fifteen years, been in constant decline. It is of particular importance that the operator has, year after year, recorded a negative balance of business. The way out of the current unfavorable situation in the sector of passenger traffic is based on the application of Public Service Obligation (PSO) based on the Regulation 1370/2007. In order to solve the problems, seven realistically possible variants have been identified. This paper defines the criteria for selecting the best variant, as well as a new integrated fuzzy model for the selection of the best variant that will enable the operator to make a profit. To define the weights of criteria in this paper, we have used the fuzzy PIvot Pairwise RElative Criteria Importance Assessment (F-PIPRECIA) method, while for ranking and selection of the best variant, we have used the Fuzzy Evaluation based on Distance from Average Solution (F-EDAS) method. Results show that the seventh variant: “Increase in revenue from ticket sales and PSO services and reduction in costs“ is the best solution in current conditions. Validation tests are performed with different scenarios and approaches and show that the model is stable. A validity test was created consisting of variations in the significance of model input parameters, testing of reverse rank, applying the fuzzy Measurement Alternatives and Ranking according to the COmpromise Solution (F-MARCOS), fuzzy Simple Additive Weighing (F-SAW) method, and fuzzy Technique for Order of Preference by Similarity to Ideal Solution (F-TOPSIS). As a part of the validation tests, Spearman’s coefficient of correlation (SCC) in some scenarios is performed and weights of the criteria have been obtained using the Fuzzy Analytic Hierarchy Process (F-AHP) and Full Consistency Method (FUCOM)
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    A ROUGH MULTICRITERI A APPROACH FOR EVALU ATION OF THE SUPPLIER CRIT ERIA IN AUTOMOTIVE I NDUSTRY
    (2018) Vasiljević, Marko; Fazlollahtabar, Hamed; Stević, Željko; Vesković, Slavko
    Ensuring costs reduction and increasing competitiveness and satisfaction of end users are the goals of each participant in the supply chain. Taking into account these goals, the paper proposes methodology for defining the most important criteria for suppliers’ evaluation. From a set of twenty established criteria, i.e. four sets of criteria: finances, logistics, quality and communication and business including its sub-criteria, we have allocated the most important ones for supplier selection. Analytic Hierarchy Process (AHP) based on rough numbers is presented to determine the weight of each evaluation criterion. For the criteria evaluation we have used knowledge from the expert in this field. The efficacy of the proposed evaluation methodology is demonstrated through its application to the company producing metal washers for the automotive industry. Next a sensitivity analysis is carried out in order to show the stability of the model. For checking stability the AHP method in conventional form is used in combination with fuzzy logic
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    Development of a Novel Freight Railcar Load Planning and Monitoring System
    (MDPI, 2019) Mladenović, Snežana; Zdravković, Stefan; Vesković, Slavko; Janković, Slađana; Đorđević, Života; Đalić, Nataša
    Rail transport has unmistakable sustainable (environmental and economic) advantages in goods transportation on a massive scale. Goods loading constitutes an important segment of goods transportation by rail. Incorrect loading can be a serious threat to traffic safety as well as a generator of unforeseen expenses related to goods, railway infrastructure and vehicles. At the beginning, the paper identifies the presence of incorrect loading into freight railcars. The analysis of the available loading software has led to the conclusion that no software offers adequate support to the planning and monitoring of the loading of goods into a covered railcar using a forklift truck. For this reason, the main aim of the research is to formulate a mathematical model that includes real-world constraints, as well as the design and implementation of an original user-friendly load planning and monitoring software system. Experimental evaluations of the implemented software have been made based on single and multiple railcar pallet loading problems, considering the following three optimization criteria: maximization of wagon load weight, maximization of wagon volume utilization and maximization of weighted profit. By testing the optimization and visualization features of the software and analyzing the results, it has been concluded that it can offer full support to real load planning and monitoring problems.
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    ECONOMIC ANALYSIS OF THE PROJECT OF WAREHOUSE CENRTALIZATION IN THE PAPER PRODUCTION COMPANY
    (University of Belgrade, 2018) Stević, Željko; Mulalić, Enis; Božičković, Zdravko; Vesković, Slavko; Đalić, Irena
    In the modern conditions, business requires constant rationalization of all activities and processes that occur in the logistics system. One of the preconditions for ensuring the competitiveness in the market is to manage the own performance. This paper presents research that relates to the project of centralization of the warehouse in the company of paper production. Currently, any production facility has its own warehouse that is, through executed decomposition, proved like a poor solution. Any project requires certain investment funds, which are in this case over half million EUR, because it is a large and complex logistics company that employs about one thousand workers. The focus of this paper is an economic analysis of the project of centralization of warehouse. The new centralized system gives better results in the comparison with the current system of decentralization. Considering the savings, which are realized by switching to a centralized warehouse system, and required investment funds, repayment period of the same is slightly less than five years, what is relatively a short period.
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    EVALUATION OF THE RA ILWAY MANAGEMENT MOD EL BY USING A NEW INTEG RATED MODEL DELPHI SWARA MABAC
    (2018) Vesković, Slavko; Stević, Željko; Stojić, Gordan; Vasiljević, Marko; Milinković, Sanjin
    The functioning of each traffic system depends to a great extent on the way the rail transport system operates. Taking into account the aspect of market turbulence and the dependence on adequate delivery when it comes to freight transport and traffic in accordance with a yearly Timetable in passenger traffic, transport policies are changing with time. Therefore, this document is considering the railway management models on the territory of Bosnia and Herzegovina. For the purpose of evaluating these models, a new hybrid model has been applied, i.e. the model which includes a combination of the Delphi, SWARA (Step-Wise Weight Assessment Ratio Analysis) and MABAC (Multi-Attributive Border Approximation Area Comparison) methods. In the first phase of the study, the criteria ranking was determined based on 16 expert grades used in the Delphi Method. After that, a total of 14 decision-makers determined the mutual criteria impact, which is a prerequisite for the application of the SWARA Method used to determine the relative weight values of the criteria. The third phase involves the application of the MABAC Method for evaluating and determining the most suitable variant. In addition, a sensitivity analysis involving the application of the ARAS, WASPAS, SAW and EDAS methods has been performed, thus verifying the previously obtained variant ranking