Upravljane proizvodnjom zasnovano na modelu

Business environment demands an instant replay to different influences that appear in the production process and in the global market. The synthesis of plant-wide control structures is recognized as one of the most important production-management design problems in the process industries. To develop a production control system, an appropriate model of the production process is needed to evaluate the various control strategies. Within the model different production Key Performance Indicators (KPIs) can be identified which are used to extract the relevant information about the state of the production process. The control systems in production plants are structured hierarchically into several levels. Closed-loop control at the production-management level using production KPIs as controlled variables was implemented. In this article, the simulation model of a polymerization production plant is presented. The plant can be controlled by its input variables, which are Production speed, Raw materials’ quality and Batch schedule and the efficiency of the production is determined based on three characteristic KPIs: Productivity, Mean product quality and Mean production costs. These KPIs are used to control the process of the procedural model. To help the manager with the decisions a model predictive controller (MPC) was used. With the controller it is assured to keep Productivity and Mean product quality indicators at the defined set-points. Preliminary results show the usefulness of the proposed methodology.Poslovno okruženje zahtijeva trenutni odgovor na razne utjecaje proizvodnog procesa i globalnog tržišta. Sinteza sustava upravljanja cjelokupnim proizvodnim pogonom prepoznata je kao jedan od najznačajnijih problema procesne industrije. Za razvoj sustava upravljanja proizvodnjom nužan je odgovarajući model proizvodnog procesa za vrednovanje raznih struktura upravljanja. Razni proizvodni Kjučni Indikatori Kakvoće (KIK) mogu se identificirati u okviru modela i koristiti za izlučivanje relevantnih informacija o stanju proizvodnog procesa. Sustav upravljanja proizvodnim postrojenjem strukturiran je u nekoliko hijerarhijskih razina. Na razini upravljanja proizvodnjom izvedeno je upravljanje u zatvorenoj petlji s proizvodnim KIK kao upravljanim varijablama. U radu je prikazana simulacija polimerizacijskog proizvodnog postrojenja. Tim se postrojenjem može upravljati pomoću njegovih ulaznih varijabla, koje su: brzina proizvodnje, kakvoća sirovine i slijed šaržnog procesa. Učinkovitost proizvodnje određuje se na osnovi sljedeća tri KIK: proizvodnost, očekivana kakvoća proizvoda i očekivani proizvodni troškovi. Ovi su KIK korišteni za upravljanje proceduralnim modelom procesa. Primijenjen je modelski prediktivni regulator za pomoć menadžerima u donošenju odluka. Regulator održava proizvodnost i očekivanu kakvoću proizvoda na zadanim vrijednostima. Preliminarni rezultati ukazuju na korisnost predložene metodologije

Vodenje proizvodnje polimerizacije z uporabo proizvodnih kazalnikov učinkovitosti

The specifics of process manufacturing have a great influence on production management. The focus of process-production control is to maintain stable and cost-effective production within given constraints. The synthesis of production-control structures is thus recognized as one of the most important design problems in process-production management. This article proposes a closed-loop control structure with the utilization of production-performance indicators (pPIs) as a possible solution to this problem. Suggested concept takes into account also economic issues of production. pPIs represent the translation of operating objectives, such as the minimization of production costs, to a reduced set of control variables that can then be used in a feedback control. The idea of production-feedback control using production pPIs as controlled variables was implemented on a procedural model of a production process for a polymerization plant. Preliminary results demonstrate the usefulness of the proposed methodology. At the implementation stage we must be aware that appropriate IT system has to be available which ensures needed online production data.Posebnosti procesne industrije imajo velik vpliv na vodenje proizvodnje. Poudarek vodenja proizvodnje v tovrstnih industrijah je na vzdrževanju stabilne in stroškovno učinkovite proizvodnje znotraj danih omejitev. Načrtovanje strukture sistema vodenja proizvodnje tako predstavlja enega izmed najbolj zahtevnih problemov. Kot možna rešitev omenjenega problema je v prispevku predlagan koncept zaprtozančnega vodenja z uporabo proizvodnih kazalnikov učinkovitosti (pPIs). Predlagan koncept upošteva tudi ekonomski vidik proizvodnje. Uporaba kazalnikov učinkovitosti omogoča prevedbo doseganja globalnih ciljev proizvodnje (npr. minimizacijo proizvodnih stroškov) v ustrezno izvedeno zaprtozančno vodenje izbrane podmnožice procesnih veličin. Ideja zaprtozančnega vodenja, kjer kazalnike pPI uporabimo kot regulirane veličine, je bila preizkušena na proceduralnem modelu proizvodnega procesa polimerizacije. Preliminarni rezultati kažejo na uporabnost predlagane metodologije ob predpogoju, da je v fazi implementacije potrebno zagotoviti ustrezno informacijsko podporo za zagotavljanje vseh potrebnih podatkov za vodenje proizvodnje

Vodenje proizvodnje polimerizacije z uporabo proizvodnih kazalnikov učinkovitosti

The specifics of process manufacturing have a great influence on production management. The focus of proc tion control is to maintain stable and cost-effective production within given constraints. The synthesis of produ structures is thus recognized as one of the most important design problems in process-production management proposes a closed-loop control structure with the utilization of production-performance indicators (pPIs) as a poss to this problem. Suggested concept takes into account also economic issues of production. pPIs represent the tr operating objectives, such as the minimization of production costs, to a reduced set of control variables that can th in a feedback control. The idea of production-feedback control using production pPIs as controlled variables was im on a procedural model of a production process for a polymerization plant. Preliminary results demonstrate the u the proposed methodology. At the implementation stage we must be aware that appropriate IT system has to which ensures needed online production data.Posebnosti procesne industrije imajo velik vpliv na vodenje proizvodnje. Poudarek vodenja proizvodnje v tovrstnih indus- trijah je na vzdrževanju stabilne in stroškovno učinkovite proizvodnje znotraj danih omejitev. Načrtovanje strukture sistema vodenja proizvodnje tako predstavlja enega izmed najbolj zahtevnih problemov. Kot možna rešitev omenjenega problema je v prispevku predlagan koncept zaprtozančnega vodenja z uporabo proizvodnih kazalnikov učinkovitosti (pPIs). Predlagan koncept upošteva tudi ekonomski vidik proizvodnje. Uporaba kazalnikov učinkovitosti omogoča prevedbo doseganja globalnih ciljev proizvodnje (npr. minimizacijo proizvodnih stroškov) v ustrezno izvedeno zaprtozančno vodenje izbrane podmnožice procesnih veličin. Ideja zaprtozančnega vodenja, kjer kazalnike pPI uporabimo kot regulirane veličine, je bila preizkušena na proceduralnem modelu proizvodnega procesa polimerizacije. Preliminarni rezultati kažejo na uporabnost predlagane metod- ologije ob predpogoju,, da je v fazi implementacije potrebno zagotoviti ustrezno informacijsko podporo za zagotavljanje vseh potrebnih podatkov za vodenje proizvodnje

Cost optimisation of supermarket refrigeration system with hybrid model

Refrigeration systems based on vapour compression cycle are one of the largest energy consumers in supermarkets. In this paper a hybrid model of a refrigeration system is developed, in order to estimate the benefits of energy optimisation measures. The refrigeration model comprises the refrigerated display case dynamics, food products dynamics, evaporation model, and ice formation model, and is further extended with the discrete events that are typical for normal operation of a refrigeration system (i.e. customer interactions, product refilling, defrosting). Model parameters are identified from the measured data, equipment specifications and estimations of some conditions in a supermarket case study. The simulation software AnyLogic is used to realise an agent-based model of the display case that allows us to extend the model to the entire store-wide refrigeration system. The analysis demonstrates the use of the model for system optimisation purposes. The defrosting schedule of a single display case as well as for the complete store is optimised considering the overall running costs, food quality, and maximum peak power. Moreover, several energy optimisation measures are compared and evaluated in terms of their contribution to the overall savings and food quality degradation