Wyniki wyszukiwania - Biblioteka Nauki

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Risk management in the allocation of vehicles to tasks in transport companies using a heuristic algorithm

100%

Izdebski M.

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tom Vol. 67, iss. 3

139--153

EN

The work deals with the issue of assigning vehicles to tasks in transport companies, taking into account the minimization of the risk of dangerous events on the route of vehicles performing the assigned transport tasks. The proposed risk management procedure based on a heuristic algorithm reduces the risk to a minimum. The ant algorithm reduces it in the event of exceeding the limit, which differs from the classic methods of risk management, which are dedicated only to risk assessment. A decision model has been developed for risk management. The decision model considers the limitations typical of the classic model of assigning vehicles to tasks, e.g. window limits and additionally contains limitations on the acceptable risk on the route of vehicles' travel. The criterion function minimizes the probability of an accident occurring along the entire assignment route. The probability of the occurrence of dangerous events on the routes of vehicles was determined based on known theoretical distributions. The random variable of the distributions was defined as the moment of the vehicle's appearance at a given route point. Theoretical probability distributions were determined based on empirical data using the STATISTICA 13 package. The decision model takes into account such constraints as the time of task completion and limiting the acceptable risk. The criterion function minimizes the probability of dangerous events occurring in the routes of vehicles. The ant algorithm has been validated on accurate input data. The proposed ant algorithm was 95% effective in assessing the risk of adverse events in assigning vehicles to tasks. The algorithm was run 100 times. The designated routes were compared with the actual hours of the accident at the bottom of the measurement points. The graphical interpretation of the results is shown in the PTV Visum software. Verification of the algorithm confirmed its effectiveness. The work presents the process of building the algorithm along with its calibration.

2

Risk assessment for rail freight transport operations

51%

Szaciłło L. , Jacyna M. , Szczepański E. , Izdebski M.

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tom Vol. 23, no. 3

476--488

EN

The aim of this article is to assess the risk of performance of rail freight transport on the basis of an analysis of identified risk areas based on statistical data on the causes of accidents that occurred on the lines of railway transport in Poland. A critical review of selected scientific studies relating to the risk assessment process for identified areas of the railway system has been undertaken. Based on statistical data, the authors analysed the causes of accidents on railway lines in 2019 in Poland and determined the probability of occurrence of a given cause. In addition, the article calculates the probability of vehicle delays for different emergency situations occurring in the performance of rail freight transport operations. This enabled the authors of the article to carry out a risk assessment of freight train delays on railway lines.

3

The use of a supply chain configuration model to assess the reliability of Logistics processes

38%

Wasiak M. , Jacyna-Gołda I. , Markowska K. , Jachimowski R. , Kłodawski M. , Izdebski M.

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tom Vol. 21, no. 3

367--374

EN

The article presents an approach to assessing the reliability of logistics processes implemented in supply chains in terms of time losses resulting from the selection of a variant of material flows in the supply chain. In order to define this indicator, a mathematical model of the supply chain has been developed, i.e. the parameters of the research problem, the decision variables, the constraints and the evaluation criteria. The method of evaluating the reliability of the system is presented in diagram form. The algorithm was verified based on experimental data. In order to evaluate the reliability of the logistic processes for the sample supply chain, a simulation model was developed that determines the time losses in the points and linear elements of the examined chain. Time losses are dictated by traffic delays resulting from traffic congestion on particular sections of the route and road junctions and delays in point elements in the supply chain.

PL

W artykule przedstawiono podejście do oceny niezawodności procesów logistycznych realizowanych w łańcuchach dostaw w aspekcie strat czasu wynikających z wyboru wariantu realizacji przepływów materiałowych w łańcuchu dostaw. Na potrzeby tych badań opracowano model matematyczny łańcucha dostaw, tj. określono parametry problemu badawczego, zmienne decyzyjne, ograniczenia oraz kryteria oceny. Sposób oceny niezawodności systemu został przedstawiony w postaci schematu. Algorytm został zweryfikowany na podstawie danych eksperymentalnych. W celu oceny niezawodności procesów logistycznych dla przykładowego łańcucha dostaw opracowano model symulacyjny wyznaczający straty czasu w elementach punktowych i liniowych badanego łańcucha. Straty czasu podyktowane są opóźnieniami w ruchu drogowym wynikającymi z kongestii ruchu na poszczególnych odcinkach trasy i węzłach drogowych oraz opóźnieniami w elementach punktowych łańcucha dostaw.