The Redesign of Processes’ Development in Food Production Organizations Using Quality Engineering Methods and Tools

A number of trends and challenges such as increased competition, new technologies and regulations, quality and new consumer trends have been forcing the food industry to change [1, 2, 3]. In response to these new challenges, food companies are improving compet‐ itiveness by restructuring, redesigning existing processes, and intensifying the fight for mar

Metodologija dizajniranja simulacijskih sustava temeljenih na metodi diskretnih događaja u proizvodnom ambijentu

The paper considers Discrete Event Simulation design methodology. Primary objective is proposal of comprehensive, scientifically established design methodology to structure, guide, and improve manufacturing processes modeling efforts. Proposed approach replicate structure and behavior of original system at desired level of abstraction, incorporates specific academic knowledge in simulation solution and results in object oriented application architecture completely consistent with production planning and scheduling ontology. The paper begins pointing out importance of modeling and equality between knowledge and models from viewpoint of modern cybernetic science and referenced cybernetics theory relocates in manufacturing systems and discrete event simulation domain. Paper then proceeds to discuss a structure and main steps of proposed methodology with a more detailed discussion of simulation based production planning and scheduling. Finally, an example of successfully designed simulation solution is given. Proposed approach gives verbal and mathematical problem description, builds ontology of problem domain, uses Extended Petri Nets, event graphs and activity cycle diagrams as modeling tools, in order to obtain faithful model which easily can be replicated in object oriented class and object hierarchy. Methodology highlights inevitability of knowledge transfer between business processes, software development and academic research experts. Integration and overlapping of mentioned fields of knowledge result in object oriented application architecture fully consistent with ontology derived from conceptual phase of design methodology. Proposed methodology enables convergence of comprehensive but static MIS knowledge in dynamic simulation model in order to fully utilize its prediction power for effective integration of strategic and tactical decision making.U radu se razmatra metodologija dizajniranja računalnih simulacijskih sustava temeljenih na metodi diskretnih događaja. Primarni cilj je prijedlog sveobuhvatne, znanstveno utemeljene metodologije dizajniranja koja formulira, usmjerava te poboljšava nastojanja modeliranja proizvodnih procesa. Predloženi pristup replicira strukturu i ponašanje originalnih sustava na željenoj razini apstrakcije, inkorporira specifična akademska znanja u simulacijski sustav te rezultira u objektno orijentiranoj arhitekturi aplikacije koja je u potpunosti konzistentna sa ontologijom planiranja i terminiranja proizvodnje. Rad započinje naglašavanjem značaja modeliranja stavljajući znak jednakosti između znanja i modela iz perspektive moderne kibernetičke znanosti te pomenutu kibernetičku teoriju relocira u domene proizvodnih sustava i simulacije diskretnih događaja. U radu se potom daju osnovni podaci o strukturi i glavnim koracima predložene metodologije uz detaljnije objašnjenje planiranja i terminiranja proizvodnje uz pomoć simulacije. Na kraju se opisuje primjer uspješno dizajniranog simulacijskog sustava. Predloženi pristup daje verbalni i matematički opis problema, gradi ontologiju domene problema, koristi proširene Petrijeve mreže, graf događaje i cikluse dijagrama aktivnosti kao alate modeliranja, sa svrhom dobijanja vjernog modela koji se lako može replicirati u objektno orijentiranu hijerarhiju klasa i objekata. Metodologija ističe neizbježnost transfera znanja između stručnjaka za poslovne procese, te eksperata iz oblasti razvoja softvera i akademskih istraživanja. Integracija i preklapanje navedenih polja znanja rezultuje u objektno orijentiranoj arhitekturi aplikacije koja je potpuno u skladu s ontologijom koja slijedi iz konceptualne faze metodologije dizajniranja. Predložena metodologija omogućava konvergenciju sveobuhvatnog ali statičkog znanja sadržanog u informacijskom sustavu upravljanja u dinamički simulacijski model, sa ciljem potpunijeg iskorišćenja mogućnosti predviđanja te učinkovito integriranje strateškog i taktičkog odlučivanja

Casting process optimization by the regression analysis applied on the wear resistant parts molding

Provodeći sveobuhvatno istraživanje procesa lijevanja dijelova otpornih na habanje (lijevanje bijelog željeza), uspostavljena je značajna korelacija između tehnoloških parametara (temperatura, vrijeme starenja u kalupu i protok rashladnog sredstva) i tvrdoće finalnog proizvoda. Osnovna teorija Box-Wilsonove metode gradijenta činila je osnovu za predviđena istraživanja. Ta metoda definira koherentnost parametara procesa budući da je njihova disperzija u ispitivanom procesu relativno mala. Glavni je cilj eksperimenta bila definicija optimalnih uvjeta lijevanja. Stoga su identificirane različite tehnološke rute i modifikacije u procesu lijevanja dok se nije postigao najbolji rezultat. Ciljna je funkcija u početku imala oblik hipoteze, ali je kasnije dobila konzistentan oblik primjenom statističkih podataka dobivenih eksperimentom, optimizacijom procesa i upravljanjem procesom na bazi empirijske povratne veze.Conducting a comprehensive research of the casting process of wear resistant parts (white hard casting), a significant correlation is established between the technological parameters (temperature, aging time in the mold and coolant flow) and the final product hardness. The fundamental theory of Box-Wilson\u27s gradient method marked the baseline for the foreseen researches. The method defines the coherence of the process parameters, since their dispersion in the examined process is relatively small. Main target of the experiment was a definition of the optimal casting conditions. Therefore the different technological routes are identified and the casting process is modified until the best outcome is achieved. Target function was initially in a hypothesized form, while later on evolved into a consistent form due to the application of experiment-statistics, process optimization and process management based on empirical feedback

Rukovođenje i kvaliteta u javnom sektoru

Shown the possibility of using ORC technology to transform low temperature heat source into electricity. Applying ORC CHP to be getting heat and electricity from a single heat source. A review is given ORC manufacturers with ranges of power, heat source, temperature levels and used working fluid. As the working fluid plays a key role in the ORC system the generalized methodology of choice of working fluid is given. The comparison of the most commonly used working fluid through their influence on the thermodynamic or exergy efficiency of the ORC process is conducted, but also the environment and human health consequences are taken into consideration. It has been shown that the ORC system can be applied in small communities or industrial plants that have a sufficient amount of biomass to meet its demand for electricity and thermal energy.Prikazane su mogućnosti upotrebe ORC tehnologija za transformaciju niskotemperaturnih izvora topline u električnu energiju. Primjenom ORC kogeneracijskih postrojenja na biomasu omogućava se dobivanje toplinske i električne energije iz jednog izvora topline. Dat je pregled ORC proizvođača sa rasponima snaga, toplinskim izvorom, temperaturnim razinama i korištenim radnim fluidom. Kako radni fluid igra ključnu ulogu u radu ORC sistema dana je uopćena metodologija izbora radnog fluida. Izvršeno je poređenje najčešće korištenih radnih fluida kroz njihov utjecaj na termodinamičku ili eksergijsku učinkovitost ORC procesa, ali i na okoliš i zdravlje ljudi. Dokazano je da se ORC sistem može primijeniti u malim lokalnim zajednicama ili industrijskim pogonima koji raspolažu dovoljnom količinom biomase za zadovoljenje svojih potreba za električnom i toplinskom energijom

Fuzzy Approach in Ranking of Banks according to Financial Performances

Evaluating bank performance on a yearly basis and making comparison among banks in certain time intervals provide an insight into general financial state of banks and their relative position with respect to the environment (creditors, investors, and stakeholders). The aim of this study is to propose a new fuzzy multicriteria model to evaluate banks respecting relative importance of financial performances and their values. The relative importance of each pair of financial performance groups is assessed linguistic expressions which are modeled by triangular fuzzy numbers. Fuzzy Analytic Hierarchical Process (FAHP) is applied to determine relative weights of the financial performances. In order to rank the treated banks, new model based on Fuzzy Technique for Order Performance by Similarity to Ideal Solution (FTOPSIS) is deployed. The proposed model is illustrated by an example giving real life data from 12 banks having 80% share of the Serbian market. In order to verify the proposed FTOPSIS different measures of separation are used. The presented solution enables the ranking of banks, gives an insight of bank's state to stakeholders, and provides base for successful improvement in a field of strategy quality in bank business

Fuzzy Approach in Ranking of Banks according to Financial Performances

Evaluating bank performance on a yearly basis and making comparison among banks in certain time intervals provide an insight into general financial state of banks and their relative position with respect to the environment (creditors, investors, and stakeholders). The aim of this study is to propose a new fuzzy multicriteria model to evaluate banks respecting relative importance of financial performances and their values. The relative importance of each pair of financial performance groups is assessed linguistic expressions which are modeled by triangular fuzzy numbers. Fuzzy Analytic Hierarchical Process (FAHP) is applied to determine relative weights of the financial performances. In order to rank the treated banks, new model based on Fuzzy Technique for Order Performance by Similarity to Ideal Solution (FTOPSIS) is deployed. The proposed model is illustrated by an example giving real life data from 12 banks having 80% share of the Serbian market. In order to verify the proposed FTOPSIS different measures of separation are used. The presented solution enables the ranking of banks, gives an insight of bank's state to stakeholders, and provides base for successful improvement in a field of strategy quality in bank business