Wyniki wyszukiwania - Biblioteka Nauki

1

Novel supply chain concepts and optimization of virtual enterprises to reduce cost, increase productivity and boost competitiveness

100%

Kovács G.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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tom Vol. 66, nr 6

973--980

EN

Global competition and increasingly complex networks of supply chains require new production philosophies, novel supply chain paradigms (Lean, Agile and Hybrid ones) and new organization and cooperation forms of companies in order to reduce cost, increase productivity and boost competitiveness. Therefore, members of an Agile supply chain form a virtual enterprise (VE) network, which stands for temporary cooperation of VE members (final assemblers, suppliers, service providers) in which the members share their skills, human and equipment resources as well as waste for more efficient operation. The goal of this study is VE optimization, which means forming optimum combinations of potential chain members. This innovative and original approach involves developing an optimization method and defining objective functions (total cost, total lead time) and design constraints (production and service capacities, inventories and members flexibility) for optimum formation of VEs. The focus of VE optimization is to manufacture and deliver final products to customers in the most time- and cost-effective manner, with the total cost and total lead time of the supply chain being minimized during the optimization. Unique optimization software has been developed based on this method. It can can be widely used for optimizing micro- and macro regional virtual networks.

2

Layout design for efficiency improvement and cost reduction

100%

Kovács G.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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tom Vol. 67, nr 3

547--555

EN

In a reality of global competition, companies have to minimize production costs and increase productivity in order to boost com-petitiveness. Facility layout design is one of the most important and frequently used efficiency improvement methods for reducing operational costs in a significant manner. Facility layout design deals with optimum location of facilities (workstation, machine, etc.) on the shop floor and optimum material flow between these objects. In this article, the objectives and procedure of layout design along with the calculation method for layout optimization are all introduced. The study is practice-oriented because the described case study shows how the layout of an assembly plant can be modified to form an ideal re-layout. The research is novel and innovative because the facility layout design and 4 lean methods (takt-time design, line balance, cellular design and one-piece flow) are all combined in order to improve efficiency more significantly, reduce costs and improve more key performance indicators. From the case study it can be concluded that the layout redesign and lean methods resulted in significant reduction of the following seven indicators: amount of total workflow, material handling cost, total travel distance of goods, space used for assembly, number of workers, labor cost of workers and the number of Kanban stops.

3

Freight and warehouse exchanges: modern logistic information systems

100%

Kovács G.

Research in Logistics & Production

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2012

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tom Vol. 2, No. 1

43-54

EN

The paper begins with a description about the services of electronic freight and ware-house exchanges currently available on the Internet, then, continues to point out their shortcomings. Based on this, it demonstrates the participants, the aims, the structure and the services of a logistically and economically ideal electronic freight and warehouse exchange system. Then it presents the e-commerce toolbar (catalogue, tenders, auctions), which gives the framework of choosing. It empha-sises the application of a self-developed multi-criteria decision supporting algorithm (based on AHP – Analytic Hierarchy Process -) in the assessment of offers received for tender. The paper describes one optimum search problem emerging in electronic freight and warehouse exchanges, then presents, in details, the ant colony algorithm (BA_ACO) for its solution (to support the complex logistics processes). The demonstration of the modules and operational process of this system is done with the help of self-developed VBA-based (Visual Basic Application) algorithms.

4

Dynamic Configuring of the Metastructur

63%

Grzybowska K. , Kovács G.

LogForum

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2012

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tom Vol. 8, no. 2

99--108

EN

Background: A trend to create groups of enterprises can be observed; whose model of operation makes use of assets of large, small and medium sized companies. It is a higher level of organisational changes. This trend is described as network organisation. It is based on the so called supply chain. The Authors of this paper proposed authors' analysis dynamic configuration of the supply chain and presents an example. The supply chain is a metastructure. It is an intermediate form between a single enterprise (microstructure/microsystem) and the global economy (macrostructure/macrosystem). The metastructure is characterized by a dynamic holarchy of mutually cooperating holons (enterprises). Methods: After a brief discussion of the nature of supply chain (metrastructure) and configuration of metastructures, authors present variable supply chains in the light of morphological analysis and presents an example. Results: The key benefits of this approach are: identifying the characteristics of a supply network and modeling the flow in the entire own supply chain metastructure and possible quick adaptations to new situations. Conclusions: Configuration of a supply chain with the use of a morphological analysis is a basic action, if its goal is to optimally model the flow of goods and implementation of quick adaptation to new situations.

PL

Wstęp: Można zaobserwować tendencję do tworzenia grup przedsiębiorstw, których model działania wykorzystuje aktywa dużych, małych i średnich przedsiębiorstw. Jest to wyższy poziom zmian organizacyjnych. Tendencja ta jest opisana jako organizacja sieci. Jest ona oparta na tzw. łańcuchu dostaw (metastrukturze). Autorka proponuje analizę dynamicznej konfiguracji łańcucha dostaw oraz przedstawia jej przykład. Łańcuch dostaw jest metastrukturą. Jest to pośrednia forma pomiędzy pojedynczych przedsiębiorstwem (mikrostruktura, mikrosystem) a ekonomią światową (makrostruktura/makrosystem). Metastruktura charakteryzuje się dynamiczną holarchią wzajemnie współpracujących holonów (przedsiębiorstw). Metody: Po krótkiej dyskusji dotyczącej natury łańcucha dostaw (meta struktura) i konfiguracji meta struktur, autorzy przedstawiają różne łańcuchy dostaw w świetle analizy morfologicznej oraz przedstawiają przykład. Wyniki: Kluczowymi zaletami takiego podejścia jest identyfikacja charakterystyk sieci dostaw oraz modelowanie przepływu w całej metastrukturze łańcucha dostaw jak również wdrożenie szybkiej adaptacji w nowych sytuacjach. Wnioski: Konfiguracja łańcucha dostaw przy zastosowaniu analizy morfologicznej jest podstawowym działaniem, w sytuacjach gdy celem jest optymalnie wymodelowaniem przypływu dóbr oraz wdrożeniu szybkiej adaptacji w nowych sytuacjach

5

Solution of the TEAM workshop problem No. 7 by the Finite Element Method

63%

Kovács G. , Kuczmann M.

Przegląd Elektrotechniczny

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2011

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tom R. 87, nr 3

99-102

EN

This paper presents some potential formulations which can be derived from the "qoasi-static" Maxwell's equations. The simulation results of the potential formulations are compared with each others focusing their CPU times and their accuracy - and with the measurement results, as The model -which was simulated - the TEAM workshop problem No. 7. The magnetic flux density and the eddy current were shown by the results of the simulation.

PL

W artykule przedstawiono sformułowania potencjałowe wyprowadzone z quasi-statycznych równań Maxwella. Wyniki symulacji sformułowań potencjałowych są porównywane między sobą w aspekcie czasu CPU i dokładności oraz z wynikami pomiarów. Model symulowany w tej pracy pochodzi z katalogu problemów sformułowanych przez TEAM Workshop i ma numer 7. Pokazano strumień magnetyczny oraz prądy wirowe.

6

The supply chain in cloud computing

51%

Grzybowska K. , Kovács G. , Lénárt B.

Research in Logistics & Production

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2014

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tom Vol. 4, No. 1

33--44

EN

Firstly, the paper presents the definition and evolution of supply chains. On the other hand, it details the use of mobile solutions in the supply chain and the characteristics, models and forms of cloud computing. Based on these, the paper describes the IT technical approach of cloud supply chains, and it presents the electronic freight and warehouse exchanges as a type of hybrid cloud supply chains. Moreover, the paper contains the new challenges and opportunities of cloud supply chains.

7

Tectonic geomorphometric studies in the surroundings of Rechnitz tectonic window, Eastern Alps

51%

Kovács G. , Telbisz T. , Székely B. , Koma Z.

Geologia Sudetica

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2014

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tom Vol. 42

188--189

8

Production logistics simulation supported by process description languages

51%

Bohács G. , Kovács G. , Rinkács A.

Management and Production Engineering Review

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2016

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tom Vol. 7, No. 1

13--20

EN

The process description languages are used in the business may be useful in the optimization of logistics processes too. The process description languages would be the obvious solution for process control, to handle the main sources of faults and to give a correct list of what to do during the logistics process. Related to this, firstly, the paper presents the main features of the frequent process description languages. The following section describes the currently most used process modelling languages, in the areas of production and construction logistics. In addition, the paper gives some examples of logistics simulation, as another very important field of logistics system modelling. The main edification of the paper, the logistics simulation supported by process description languages. The paper gives a comparison of a Petri net formal representation and a Simul8 model, through a construction logistics model, as the major contribution of the research.

9

Hybrid model of an expert system for assessing the stability of a production system

51%

Burduk A. , Grzybowska K. , Kovács G.

LogForum

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2018

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tom Vol. 14, no. 4

507--518

EN

Background: The article presents the concept of control of the production system, which allows to maintain its stability, and thus to implement the established production plans. For this purpose, combinations of simulation models and artificial neural network (ANN) models of the production system have been suggested. The combination of both types of models was possible thanks to the development of a hybrid model of the expert system to assess the possibility of implementing the production plan (objective) depending on the risk size and the level of stability of the production system analysed. The analysed problem - the possibility of implementing production plans depending on the risk size and the level of stability of the production system - is difficult to mathematical modelling. However, based on the data analysis from the simulation model and the ANN model, we can obtain information on the dependences of the corresponding input and output values. Methods: Based on the presented method of managing the production process using computer models, the possibilities of using simulation models and ANN models in assessing the stability and risk of production systems have been analysed. The analysis and comparison of both types of models have been performed due to the construction and the type of input and output data. Results: The direct combination of simulation models and ANN models is not allowed by their different structure, specificity and other types of input and output data. Therefore, the concept of combination of both types of models presented in the article is conducted via a database of expertise and fuzzy inference. Conclusions: For the purpose of controlling the production system, it was suggested to build a hybrid model of an expert system to assess the possibility of achieving the objective depending on the risk size and the level of stability of the production systems.

PL

Wstęp: W artykule przedstawiono koncepcję sterowania systemem produkcyjnym, pozwalającą na zachowanie jego stabilności, a tym samym na realizację założonych planów produkcyjnych. W tym celu zaproponowano połączenia modeli symulacyjnych i modeli sztucznych sieci neuronowych (SSN) systemu produkcyjnego. Połączenie obydwu typów modeli było możliwe dzięki opracowaniu hybrydowego modelu systemu ekspertowego do oceny możliwości realizacji planu produkcji (celu) w zależności od wielkości ryzyka i poziomu stabilności analizowanego systemu produkcyjnego. Analizowany problem – możliwość realizacji planów produkcyjnych w zależności od wielkości ryzyka i poziomu stabilności systemu produkcyjnego – jest trudny do zamodelowania matematycznego. Jednak na podstawie analizy danych, pochodzących z modelu symulacyjnego i modelu ANN, można uzyskać informacje dotyczące zależności odpowiadających sobie wartości wejściowych i wyjściowych. Metody: Na podstawie przedstawionego sposobu zarządzania procesu produkcyjnego z wykorzystaniem modeli komputerowych, przeanalizowano możliwości zastosowania modeli symulacyjnych i modeli ANN w ocenie stabilności i ryzyka systemów produkcyjnych. Dokonano analizy i porównania obydwu typów modeli ze względu na sposób budowy oraz rodzaj danych wejściowych i wyjściowych. Wyniki: Na bezpośrednie połączenie modeli symulacyjnych i modeli SSN nie pozwala ich odmienna budowa, specyfika oraz inne rodzaje danych wejściowych i wyjściowych. Dlatego prezentowana w artykule koncepcja fuzji obydwu typów modeli odbywa się poprzez bazę wiedzy eksperckiej i wnioskowanie rozmyte. Wnioski: Na potrzeby sterowania systemem produkcyjnym, zaproponowano budowę hybrydowego modelu systemu ekspertowego do oceny możliwości realizacji celu w zależności od wielkości ryzyka i poziomu stabilności systemu produkcyjnego.

10

Simulation of complex logistical service processes

51%

Gubán M. , Kovács G. , Kot S.

Management and Production Engineering Review

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2017

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tom Vol. 8, No. 2

19--29

EN

The world around us is a very complex and multi-parametric system, like the weather, traffic, operation of machines, production processes, service processes, etc. Understanding of the characteristics, operation and behaviour of these systems and processes is not easy due to their complexity. The design of optimal production and service procedures is an essential task for planners. The target is the increasing of the efficiency of the production and service and analysis of the effect of parameter changing. There are lot of tools and sophisticated methods for design, analysis and improvement of logistical processes. The most often used analysis tool is the simulation in the production processes. Our aim in this article is to show that the simulation can be used efficiently in case of analysis of service processes, not only in case of production processes. The simulation is available for bottleneck analysis of service activities not only for production processes. In this study the simulation of a service process was realized by the AnyLogic software. The relevance of the simulation technique for analysis of complex service processes is proved by a case study of a service and maintenance activity of a multinational shopping centre.