eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Distributive trade\'s significance in national economy
Zdenko Segetlija
1
Josip Mesarić
1
Davor Dujak
1
Josip Juraj Strossmayer University in Osijek, Osijek, Croatia
Background: The paper analyzes a significance of distributive trade in contemporary national economies of select European countries (10) from the point of view of employment, gross value-added creation, supply chain establishment, and international expansion. A cause for the paper is a dissatisfactory level of economic development of certain transitional countries on one side and the high distributive trade shares (especially in the number of employees and in the GDP) on the other side.
Methods: Distributive trade's significance for a country is analyzed entirely and segmental. The data collected by Eurostat and Deloitte are analyzed and depicted graphically via usual statistical methods (relative numbers, indices and shares, tabulation and graphical depictions).
Results: The results of the research conducted should confirm a thesis on distributive trade's significance based on its shares in the economic structure; however, as an integrator in the value-creating chains, distributive trade has different significance for certain national economies, for the large-sized companies and groups (especially the retailing ones) are also expanded internationally, along with their supply chains.
Conclusions: Distributive trade does not have an equal significance for the economic development in all countries. Equally, all the divisions within distributive trade do not have equal significance for the overall country's economy, as well as for a launch of its economic development. Nevertheless, it should be necessary to analyze concentration and internationalization in detail for the sake of an evaluation of distributive trade's significance as an integrator in value-creating chains. In that respect, some transitional countries observed do lag behind.
http://www.logforum.net/vol11/issue3/no1/11_3_1_15.pdf
distributive trade
wholesale trade
retail trade
number of employees
supply chains
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Supply chain collaboration and cost saving as a result of returns handling programmes in retail corporations in Poland
Anna Maria Jeszka
1
University of Economics, Poznań, Poland
Background: The objective is to define on the basis of the literature as well as to test empirically the main factors that affect the cost saving of many retail chains, resulting from deliberate and conscious policies as well as organized activities in the area of product returns management.
Methods: Based on a survey developed for the study, standardized interviews were conducted with representatives of trade corporations in the apparel industry in Poland. The data collected were analysed statistically.
Results: The results of the statistical analysis showed that the analysed factors had a significant impact on cost saving. A company's ability to cooperate in the supply chain, limited for the purposes of the study to the distributor - retailer relationship, is relevant to the cost savings resulting from the policies of retail corporations in the area of reverse logistics. The integration of IT systems with suppliers and customers also influences the level of cost saving, as does collaboration within a team.
Conclusions: To date, studies in this field have not been conducted in Poland. A particularly important element seems to be the relationship between cooperation in the supply chain and the possible savings which this can generate. This study contributes to the growing trend of research into reverse logistics and emphasizes the role of retailers and cooperation in the supply chain.
http://www.logforum.net/vol11/issue3/no2/11_3_2_15.pdf
returns handling
supply chain collaboration
clothing industry
cost savings
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
The correlation analysis of alert notifications in the rasff to food from the non-eea countries and from the eea countries
Marcin Pigłowski
1
Gdynia Maritime University, Gdynia, Poland
Background: The RASFF (Rapid Alert System for Food and Feed) is used to quickly mutual information of member countries of the European Economic Area (EEA) on risks in food. A similar trend line course of alert notifications in the RASFF in time to food from the non-EEA countries and the EEA countries, as well as a very high value of the Pearson's r correlation coefficient (0.96) indicated an interdependence of alert notifications from these two groups of countries. Therefore, the goal of the article was to examine the strength of correlation within particular products categories and hazards categories.
Methods: Data for the study came from the RASFF database from the years 1979-2013 covering 8175 alert notifications, including the 2540 notifications to food from the non-EEA countries and 5635 notifications to food from the EEA countries. Within each products category and hazards category examined whether there was a correlation (i.e. the value of calculated statistics t exceeded the value of critical statistics t0.05;n-2), and then calculated the Pearson's r correlation coefficient.
Results: The value of Pearson's correlation coefficient indicated the occurrence of a very high correlation in the products category "Herbs and spices" (0.98), and the high correlation in the following categories: "Bivalve molluscs and products thereof" (0.70), "Dietetic foods, food supplements fortified foods" (0.86), "Fish and fish products" (0.79), "Food contact materials" (0.89), "Fruits and vegetables" (0.88) and "Meat and meat products (other than poultry)" (0.72). However, in the case of hazards categories the very high correlation occurred in the category of "Food additives and flavourings" (0.93) and "Radiation" (0.94) and the high correlation in the case of "Composition" (0.89), "Foreign bodies" (0.88), "Heavy metals" (0.80), "Mycotoxins" (0.81) and "Pathogenic micro-organisms" (0.72).
Conclusions: The results showed the need to pay particular attention by the border control authorities to food which is imported: seafood, herbs and spices, and fruits and presented in this food: heavy metals, pathogenic micro-organisms and mycotoxins. It would also shorten the supply chain and / or limit the import of certain raw materials and products, directing the attention of consumers to food produced first of all in the EEA.
http://www.logforum.net/vol11/issue3/no3/11_3_3_15.pdf
EEA
RASFF
alert notifications
products categories
hazards categories
correlation analysis
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Intermodal service - system approach
Mirosław Antonowicz
1
Kożminski University, Warsaw, Poland
Introduction: Transportation services may be described in systemic categories. Intermodal freight transport is a practical expression of the system approach to transport. Development of the intermodal transport system has brought about the need for the comprehensive grasp of transportation processes. Intermodal transport operators manage the whole transportation service organization process. Hence, a question arises whether the service offered by an intermodal transport operator may be interpreted as a complex system service. Systemness of contemporary products and services consists in that their value for clients is predefined by their place in the whole system of products and/or services as well as by the network of their users. The network language, occurring in this paper, is connected with the development of the notion of network, one of the inspiring ideas in organization and management science of the recent years.
Methods: Literature on the intermodal freight transport issue has been analysed by the present author for the purposes of this paper, with a view to the developing idea of marketing of system products. Within the adopted interpretative paradigm, qualitative / quantitative research was used. Case study is used, among others, to interpret a particular situation, in a way that the subsequent description appears as the research result and may be recognized as valuable contribution to the existent knowledge. The aim of the paper is to highlight, following the research results, the necessity to treat the service offered by intermodal transport operators in system categories. Such systemic interpretation points both to the multitude of components of the service and to the arising opportunity for comprehensive solution of the clients' needs and expectations.
Results: The outcomes reveal that the service offered by an intermodal transport operator may be recognized as the complex systemic intermodal service. They contribute to the knowledge of intermodal transport and serve as the stepping point for the development of the concept of systemic marketing in logistic services.
Conclusions: Proper determination of the systemic essence of the intermodal service constitutes the starting point for the identification of the client's problems as well as for the choice of offered solutions, both in the context of essential and additional values. Due to this reason, the management of an intermodal service creation and delivery has the nature of network management, and the values offered by an intermodal service are conditioned by material elements, without which the provision of the service in accordance with the client's expectations cannot be realized.
http://www.logforum.net/vol11/issue3/no4/11_3_4_15.pdf
Intermodal freight transport
Intermodal service
Transport system
Network
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
An inventory model for generalized weibull deteriorating items with price dependent demand and permissible delay in payments under inflation
S.P. Singh
1
Gobind Panda
2
Department of Engineering Mathematics, L.N.C.T, Bhopal, India
Department of Mathematics, M.I.E.T,BBSR,India
This paper derives an inventory model is developed for items that deteriorates at a generalized Weibull distributed rate when demand for the items is dependent on the selling price. Shortages are not allowed and price inflation is taken into consideration over finite planning horizon. A brief analysis of the cost involved is carried out by theoretical analysis.
http://www.logforum.net/vol11/issue3/no5/11_3_5_15.pdf
inventory
inflation
Weibull distribution
selling price dependent demand
delay in payment
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Transportation problem by Monalisha\'s approximation method for optimal solution (mamos)
Monalisha Pattnaik
1
Utkal University, Bhubaneswar, India
Background: This paper finds initial basic feasible solution and optimal solution to the transportation problem by using MAM's (Monalisha's Approximation Method).
Methods: Using the concept of comparison of the transportation problem by other methods of solution, the paper introduces a very effective method in terms of cost and time for solving these problems. This paper extends transportation problem by using different method of obtaining both initial basic feasible solution and optimal solution simultaneously other than existing methods.
Results and conclusions: It is presented a cost saving and less time consuming and accurate method for obtaining the best optimal solution of the transportation problem . With the problem assumptions, the optimal solution can still be theoretically solved using the existing methods. Finally, numerical examples and sensitivity analysis are presented to illustrate the effectiveness of the theoretical results, and to gain additional managerial insights.
http://www.logforum.net/vol11/issue3/no6/11_3_6_15.pdf
Transportation Problem
Monalisha\'s Approximation Method for Optimal Solution (MAMOS)
Comparative Analysis
Sensitive Analysis
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
The design of the public transport lines with the use of the fast genetic algorithm
Aleksander Król
1
Silesian University of Technology, Katowice, Poland
Background: The growing role of public transport and the pressure of economic criteria requires the new optimization tools for process of public transport planning. These problems are computationally very complex, thus it is preferable to use various approximate methods, leading to a good solution within an acceptable time.
Methods: One of such method is the genetic algorithm mimicking the processes of evolution and natural selection in the nature. In this paper, the different variants of the public transport lines layout are subjected to the artificial selection. The essence of the proposed approach is a simplified method of calculating the value of the fit function for a single individual, which brings relatively short computation time even for large jobs.
Results: It was shown that despite the introduced simplifications the quality of the results is not worsened. Using the data obtained from KZK GOP (Communications Municipal Association of Upper Silesian Industrial Region) the described algorithm was used to optimize the layout of the network of bus lines located within the borders of Katowice.
Conclusion: The proposed algorithm was applied to a real, very complex network of public transportation and a possibility of a significant improvement of its efficiency was indicated. The obtained results give hope that the presented model, after some improvements can be the basis of the scientific method, and in a consequence of a further development to find practical application.
http://www.logforum.net/vol11/issue3/no7/11_3_7_15.pdf
genetic algorithm
public transport
optimization
bus lines
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Model of the impact of parameters controlling replenishment in the bs (min-max) continuous review system on the actual inventory availibility
Stanisław Krzyżaniak
1
Institute of Logistics and Warehousing, Poznań, Poland
Background: Due to random changes in demand, inventory management is still - despite the development of alternative goods flow management concepts - an important issue both in terms of costs of maintenance and replenishment as well as the level of service measured by inventory availability levels. There are a number of replenishment systems to be used in such conditions, but they are most often formed on the basis of two basic ones: a system based on the reorder point and based on periodic inspection. This paper refers to the former system, the BS system (min-max), in which an order is placed after reaching inventory level B (information level, reorder point) for a quantity allowing to reach level S. This system is very often used in business practice. Observations conducted under realistic conditions indicate the need to improve the classical models describing the system. This results, among other things, from the fact that the actual level of available inventory at the start of the replenishment cycle may be significantly lower than level B, resulting in lower than expected levels of customer service. Taking account of this phenomenon through model determination of the cumulative distribution function for the observed difference makes it possible to select the correct parameters to control the replenishment system in question and - therefore - to achieve the expected economic effects.
Methods: The object of the study is to create a mathematical model allowing the determination of the required inventory level B taking into account the difference D between this level and the actual level of inventory at the start of the replenishment cycle. To determine the effect of various factors such as demand distribution parameters in the adopted unit of time and the difference between level S (max) and B (min), a dedicated tool (simulator in EXCEL spreadsheet) for determining the distribution of frequency of value D has been developed. Then a mathematical model allowing the determination of the distribution and its parameters as a function of the difference r = S-B for virtually any distribution of demand has been developed and implemented in a separate EXCEL spreadsheet.
Results: It was found that there is the need to take into account the distribution of the difference between the information level B (the reaching or exceeding of which is a signal to place an order) and the actual level of inventory at the start of the replenishment cycle when determining the inventory replenishment control parameters in the BS system. A mathematical model allowing to determine the incidence and distribution of function of value depending on the demand distribution parameters and difference r between the S level (max) and B level (min) has been developed and used for calculations. High compatibility of results obtained from model calculations with the results obtained through simulation imitating real events has been shown.
Conclusions: The model described in this paper will allow a more accurate determination of parameters that control the BS system to safeguard the required level of service and conditions relating to the volume of deliveries. Further work is required to develop an effective model solution for a general formula presented in this paper used to calculate the B parameter as a function of the required service level and the S parameter depending on the designated (e.g. economic) average delivery.
http://www.logforum.net/vol11/issue3/no8/11_3_8_15.pdf
inventory management
restocking in the BS system (min-max
up-to-level review continuous review replenishment model)
level of service
modelling
simulation
eng
Poznan School of Logistics
Logforum
1734459X
2015-09-30
11
3
article
Estimating order-picking times for return heuristic - equations and simulations
Grzegorz Tarczyński
1
Wroclaw University of Economics, Wrocław, Poland
Background: A key element of the evaluation of warehouse operation is the average order-picking time. In warehouses where the order-picking process is carried out according to the "picker-to-part" rule the order-picking time is usually proportional to the distance covered by the picker while picking items. This distance can by estimated by simulations or using mathematical equations. In the paper only the best described in the literature one-block rectangular warehouses are considered.
Material and methods: For the one-block rectangular warehouses there are well known five routing heuristics. In the paper the author considers the return heuristic in two variants. The paper presents well known Hall's and De Koster's equations for the average distance traveled by the picker while completing items from one pick list. The author presents own proposals for calculating the expected distance.
Results: the results calculated by the use of mathematical equations (the formulas of Hall, De Koster and own propositions) were compared with the average values obtained using computer simulations. For the most cases the average error does not exceed 1% (except for Hall's equations). To carry out simulation the computer software Warehouse Real-Time Simulator was used.
Conclusions: the order-picking time is a function of many variables and its optimization is not easy. It can be done in two stages: firstly using mathematical equations the set of the potentially best variants is established, next the results are verified using simulations. The results calculated by the use of equations are not precise, but possible to achieve immediately. The simulations are more time-consuming, but allow to analyze the order-picking process more accurately.
http://www.logforum.net/vol11/issue3/no9/11_3_9_15.pdf
order-picking
warehousing
heuristics
simulations