890 resultados para Construction process improvement
Resumo:
This thesis attempts to find whether scenario planning supports the organizational strategy as a method for addressing uncertainty. The main issues are why, what and how scenario planning fits in organizational strategy and how the process could be supported to make it more effective. The study follows the constructive approach. It starts with examination of competitive advantage and the way that an organization develops strategy and how it addresses the uncertainty in its operational environment. Based on the conducted literature review, scenario methods would seem to provide versatile platform for addressing future uncertainties. The construction is formed by examining the scenario methods and presenting suitable support methods, which results in forming of the theoretical proposition for supporter scenario process. The theoretical framework is tested in laboratory conditions, and the results from the test sessions are used a basis for scenario stories. The process of forming the scenarios and the results are illustrated and presented for scrutiny
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The changing business environment demands that chemical industrial processes be designed such that they enable the attainment of multi-objective requirements and the enhancement of innovativedesign activities. The requirements and key issues for conceptual process synthesis have changed and are no longer those of conventional process design; there is an increased emphasis on innovative research to develop new concepts, novel techniques and processes. A central issue, how to enhance the creativity of the design process, requires further research into methodologies. The thesis presentsa conflict-based methodology for conceptual process synthesis. The motivation of the work is to support decision-making in design and synthesis and to enhance the creativity of design activities. It deals with the multi-objective requirements and combinatorially complex nature of process synthesis. The work is carriedout based on a new concept and design paradigm adapted from Theory of InventiveProblem Solving methodology (TRIZ). TRIZ is claimed to be a `systematic creativity' framework thanks to its knowledge based and evolutionary-directed nature. The conflict concept, when applied to process synthesis, throws new lights on design problems and activities. The conflict model is proposed as a way of describing design problems and handling design information. The design tasks are represented as groups of conflicts and conflict table is built as the design tool. The general design paradigm is formulated to handle conflicts in both the early and detailed design stages. The methodology developed reflects the conflict nature of process design and synthesis. The method is implemented and verified through case studies of distillation system design, reactor/separator network design and waste minimization. Handling the various levels of conflicts evolve possible design alternatives in a systematic procedure which consists of establishing an efficient and compact solution space for the detailed design stage. The approach also provides the information to bridge the gap between the application of qualitative knowledge in the early stage and quantitative techniques in the detailed design stage. Enhancement of creativity is realized through the better understanding of the design problems gained from the conflict concept and in the improvement in engineering design practice via the systematic nature of the approach.
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The accumulation of aqueous pollutants is becoming a global problem. The search for suitable methods and/or combinations of water treatment processes is a task that can slow down and stop the process of water pollution. In this work, the method of wet oxidation was considered as an appropriate technique for the elimination of the impurities present in paper mill process waters. It has been shown that, when combined with traditional wastewater treatment processes, wet oxidation offers many advantages. The combination of coagulation and wet oxidation offers a new opportunity for the improvement of the quality of wastewater designated for discharge or recycling. First of all, the utilization of coagulated sludge via wet oxidation provides a conditioning process for the sludge, i.e. dewatering, which is rather difficult to carry out with untreated waste. Secondly, Fe2(SO4)3, which is employed earlier as a coagulant, transforms the conventional wet oxidation process into a catalytic one. The use of coagulation as the post-treatment for wet oxidation can offer the possibility of the brown hue that usually accompanies the partial oxidation to be reduced. As a result, the supernatant is less colored and also contains a rather low amount of Fe ions to beconsidered for recycling inside mills. The thickened part that consists of metal ions is then recycled back to the wet oxidation system. It was also observed that wet oxidation is favorable for the degradation of pitch substances (LWEs) and lignin that are present in the process waters of paper mills. Rather low operating temperatures are needed for wet oxidation in order to destruct LWEs. The oxidation in the alkaline media provides not only the faster elimination of pitch and lignin but also significantly improves the biodegradable characteristics of wastewater that contains lignin and pitch substances. During the course of the kinetic studies, a model, which can predict the enhancements of the biodegradability of wastewater, was elaborated. The model includes lumped concentrations suchas the chemical oxygen demand and biochemical oxygen demand and reflects a generalized reaction network of oxidative transformations. Later developments incorporated a new lump, the immediately available biochemical oxygen demand, which increased the fidelity of the predictions made by the model. Since changes in biodegradability occur simultaneously with the destruction of LWEs, an attempt was made to combine these two facts for modeling purposes.
Resumo:
It is generally accepted that between 70 and 80% of manufacturing costs can be attributed to design. Nevertheless, it is difficult for the designer to estimate manufacturing costs accurately, especially when alternative constructions are compared at the conceptual design phase, because of the lack of cost information and appropriate tools. In general, previous reports concerning optimisation of a welded structure have used the mass of the product as the basis for the cost comparison. However, it can easily be shown using a simple example that the use of product mass as the sole manufacturing cost estimator is unsatisfactory. This study describes a method of formulating welding time models for cost calculation, and presents the results of the models for particular sections, based on typical costs in Finland. This was achieved by collecting information concerning welded products from different companies. The data included 71 different welded assemblies taken from the mechanical engineering and construction industries. The welded assemblies contained in total 1 589 welded parts, 4 257 separate welds, and a total welded length of 3 188 metres. The data were modelled for statistical calculations, and models of welding time were derived by using linear regression analysis. Themodels were tested by using appropriate statistical methods, and were found to be accurate. General welding time models have been developed, valid for welding in Finland, as well as specific, more accurate models for particular companies. The models are presented in such a form that they can be used easily by a designer, enabling the cost calculation to be automated.
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Static process simulation has traditionally been used to model complex processes for various purposes. However, the use of static processsimulators for the preparation of holistic examinations aiming at improving profit-making capability requires a lot of work because the production of results requires the assessment of the applicability of detailed data which may be irrelevant to the objective. The relevant data for the total assessment gets buried byirrelevant data. Furthermore, the models do not include an examination of the maintenance or risk management, and economic examination is often an extra property added to them which can be performed with a spreadsheet program. A process model applicable to holistic economic examinations has been developed in this work. The model is based on the life cycle profit philosophy developed by Hagberg and Henriksson in 1996. The construction of the model has utilized life cycle assessment and life cycle costing methodologies with a view to developing, above all, a model which would be applicable to the economic examinations of complete wholes and which would require the need for information focusing on aspects essential to the objectives. Life cycle assessment and costing differ from each other in terms of the modeling principles, but the features of bothmethodologies can be used in the development of economic process modeling. Methods applicable to the modeling of complex processes can be examined from the viewpoint of life cycle methodologies, because they involve the collection and management of large corpuses of information and the production of information for the needs of decision-makers as well. The results of the study shows that on the basis of the principles of life cycle modeling, a process model can be created which may be used to produce holistic efficiency examinations on the profit-making capability of the production line, with fewer resources thanwith traditional methods. The calculations of the model are based to the maximum extent on the information system of the factory, which means that the accuracyof the results can be improved by developing information systems so that they can provide the best information for this kind of examinations.
Resumo:
Arkitus on kartongin jatkojalostusmuoto, jonka tehokkuus muodostuu monen tekijän vaikutuksesta. Tämän työn tavoitteena oli parantaa arkitustehokkuutta tutkitussa kahden folioleikkurin arkittamossa tuotannonsuunnittelun ja tuotannonohjauksen kehittämisellä. Kartonkitehtaan sisäisessä jalostusketjussa arkitus on viimeinen vaihe, mikä tekee siitä pitkälti riippuvaisen edeltävistä konevaiheista, eli kartonkikoneista ja PE-päällystyskoneista. Pelkkä arkituksen tuotannonsuunnittelun huomiointi ei siis vielä takaa hyvää lopputulosta arkitustehokkuuden kannalta. Folioarkitustoiminta on hyvin asiakassuuntautunutta. Arkkikoot määräytyvät asiakkaiden omien tarpeiden perusteella, jolloin eri arkkikokojen kokonaismäärä kasvaa huomattavan suureksi. Viime vuosien trendinä on ollut tilauseräkokojen pieneneminen. Näiden tekijöiden yhteisvaikutuksena arkituksen tuotantoprosessille on ominaista erilaisten asetusten aiheuttama katkonaisuus. Lisäksi pelkästään yhden millimetrin muutos arkin leveydessä voi usein vaikuttaa arkitustehokkuuteen hyvinkin merkittävästi. Näistä syistä arkituksen tuotannonsuunnittelun apuvälineeksi tarvitaan tarkkuuteen ja joustavuuteen kykenevää tietojärjestelmää. Tehokkaan tuotannonohjauksen tueksi tarvitaan lisäksi erilaisia leikkuri- ja kartonkilaatukohtaisia raportteja. Työn teoriaosassa käsitellään tarkemmin arkitustoiminnan ominaisuuksia ja sen tehokkuuteen vaikuttavia tekijöitä. Lisäksi käsitellään tuotannonsuunnittelun ja tuotannonohjauksen periaatteita ja toimintoja.
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Nykyään kolmeen kerrokseen perustuvat client-server –sovellukset ovat suuri kinnostuskohde sekä niiden kehittäjille etta käyttäjille. Tietotekniikan nopean kehityksen ansiosta näillä sovelluksilla on monipuolinen käyttö teollisuuden eri alueilla. Tällä hetkellä on olemassa paljon työkaluja client-server –sovellusten kehittämiseen, jotka myös tyydyttävät asiakkaiden asettamia vaatimuksia. Nämä työkalut eivät kuitenkaan mahdollista joustavaa toimintaa graafisen käyttöliittyman kanssa. Tämä diplomityö käsittelee client-server –sovellusten kehittamistä XML –kielen avulla. Tämä lähestymistapa mahdollistaa client-server –sovellusten rakentamista niin, että niiden graafinen käyttöliittymä ja ulkonäkö olisivat helposti muokattavissa ilman ohjelman ytimen uudelleenkääntämistä. Diplomityö koostuu kahdesta ostasta: teoreettisesta ja käytännöllisestä. Teoreettinen osa antaa yleisen tiedon client-server –arkkitehtuurista ja kuvailee ohjelmistotekniikan pääkohdat. Käytannöllinen osa esittää tulokset, client-server –sovellusten kehittämisteknologian kehittämislähestymistavan XML: ää käyttäen ja tuloksiin johtavat usecase– ja sekvenssidiagrammit. Käytännöllinen osa myos sisältää esimerkit toteutetuista XML-struktuureista, jotka kuvaavat client –sovellusten kuvaruutukaavakkeiden esintymisen ja serverikyselykaaviot.
Resumo:
Biologisessa jätteenkäsittelyssä syntyvää humusmassaa voidaan käyttää maanparannusaineena ja yleisenä lannoitusaineena. Termisellä kuivauksella saadaan humuksen kuiva-ainepitoisuutta nostettua mekaanisen kuivauksen jälkeen, jolloin sen tuotteistettavuus ja kuljetettavuus paranevat pienentyneen painon ja tilavuuden myötä. Kirjallisuusosassa on esitetty yleisiä termisen kuivauksen periaatteita sekä käsitelty lähemmin humuksen kuivausta. Lisäksi termisen kuivauksen hygienisoivaa vaikutusta on esitelty kirjallisuusosan lopussa. Tutkimusosassa luotiin tietokonepohjainen malli MK Protech Oy:n kehittämälle Traypack-kuivaimelle. Mallin luomisessa käytettiin apuna suoritettujen pilot-ajojen tuloksia sekä kirjallisuudesta saatuja tietoja. Malli sisältää kuivauksen aine- ja energiataseet sekä kuivaimen ja sen apulaitteiden mitoituksen. Sen lisäksi malli tulostaa erillisinä kokonaisuuksina prosessin laiteluettelon, investointikustannuslaskelman ja elinkaarianalyysin. Lisäksi tutkimusosassa laskettiin mallin avulla Rayongin kaupunkiin Thaimaahan rakenteilla olevan jätteenkäsittelylaitoksen tarpeeseen soveltuvan kuivaimen mitoitus- ja käyttötiedot sekä tarkasteltiin kuivaimen taloudellista kannattavuutta. Laitoksessa kuivataan 2080 kg/h kuiva-ainepitoisuudeltaan 30 % humusta loppukuiva-ainepitoisuuteen 50 %. Tarvittavaksi lämpötehoksi kuivaimeen saatiin 3,9 MW. Tästä 2,0 MW tarvitaan uutta systeemiin tuotavaa kuivauskaasua. Tällöin laitoksen investointikustannuksiksi saatiin 359 000 EUR. Laitoksen käyttökustannuksiksi saatiin 40 440 EUR vuodessa.
Resumo:
Lipases have received great attention as industrial biocatalysts in areas like oils and fats processing, detergents, baking, cheese making, surface cleaning, or fine chemistry . They can catalyse reactions of insoluble substrates at the lipid-water interface, preserving their catalytic activity in organic solvents. This makes of lipases powerful tools for catalysing not only hydrolysis, but also various reverse reactions such as esterification, transesterification, aminolysis, or thiotransesterifications in anhydrous organic solvents. Moreover, lipases catalyse reactions with high specificity, regio and enantioselectivity, becoming the most used enzymes in synthetic organic chemistry. Therefore, they display important advantages over classical catalysts, as they can catalyse reactions with reduced side products, lowered waste treatment costs, and under mild temperature and pressure conditions. Accordingly, the use of lipases holds a great promise for green and economical process chemistry.
Resumo:
Työn tavoitteena oli kohdeyrityksen tuotekehitysprosessin tehostaminen. Tuotekehitysprosessin tulee huomioida sekä kaikki työvaiheet ideasta tuotantoon että kaikki tuotteen tehokkaaseen lanseeraukseen vaikuttavat toiminnot. Tuotekehitysprosessin pitää tukea rinnakkaissuunnittelua, jossa tuotteen ominaisuuksia, valmistettavuutta ja markkinointia kehitetään samanaikaisesti. Työssä käytetyt teoriat perustuvat alan kirjallisuudessa ja lehtiartikkeleissa esitettyihin malleihin tuotekehitysprosessista ja rinnakkaissuunnittelusta. Kuitenkin työ on tehty nimenomaan kohdeyrityksen tarpeisiin huomioimalla kehityksessä kaikkien prosessiin osallistuvien toimintojen näkemys tarvittavista tehtävistä. Työn tuloksena kehitettiin elektronisessa muodossa yrityksen sisäisessä tietoverkossa oleva kuvaus tuotekehitysprosessin rinnakkaisesta etenemisestä ja päätöksenteosta sekä siihen liitetty vaiheittainen toimintaohjeisto kaikille kehitystyöhön osallistuville organisaatiotahoille. Uusi tuoteprosessi luo edellytykset yhtenäiseen ja tehokkaaseen uusien tuotteiden markkinoille saattamiseen. Elektroninen rakenne helpottaa prosessin käytettävyyttä ja jatkuvaa kehittämistä. Prosessin tulee kehittyä jokaisen tuotekehitysprojektin yhteydessä.
Resumo:
Laatu on osaltaan vahvistamassa asemaansa liike-elämässä yritysten kilpaillessa kansainvälisillä markkinoilla niin hinnalla kuin laadulla. Tämä suuntaus on synnyttänyt useita laatuohjelmia, joita käytetään ahkerasti yritysten kokonais- valtaisen laatujohtamisen (TQM) toteuttamisessa. Laatujohtaminen kattaa yrityksen kaikki toiminnot ja luo vaatimuksia myös yrityksen tukitoimintojen kehittämiselle ja parantamiselle. Näihin lukeutuu myös tämän tutkimuksen kohde tietohallinto (IT). Tutkielman tavoitteena oli kuvata IT prosessin nykytila. Tutkielmassa laadittu prosessikuvaus pohjautuu prosessijohtamisen teoriaan ja kohdeyrityksen käyttämään laatupalkinto kriteeristöön. Tutkimusmenetelmänä prosessin nykytilan selvittämiseksi käytettiin teemahaastattelutta. Prosessin nykytilan ja sille asetettujen vaatimusten selvittämiseksi haastateltiin IT prosessin asiakkaita. Prosessianalyysi, tärkeimpien ala-prosessien tunnistaminen ja parannusalueiden löytäminen ovat tämän tutkielman keskeisemmät tulokset. Tutkielma painottui IT prosessin heikkouksien ja parannuskohteiden etsimiseen jatkuvan kehittämisen pohjaksi, ei niinkään prosessin radikaaliin uudistamiseen. Tutkielmassa esitellään TQM:n periaatteet, laatutyökaluja sekä prosessijohtamisen terminologia, periaatteet ja sen systemaattinen toteutus. Työ antaa myös kuvan siitä, miten TQM ja prosessijohtaminen niveltyvät yrityksen laatutyössä.
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Allocentric spatial memory, the memory for locations coded in relation to objects comprising our environment, is a fundamental component of episodic memory and is dependent on the integrity of the hippocampal formation in adulthood. Previous research from different laboratories reported that basic allocentric spatial memory abilities are reliably observed in children after 2 years of age. Based on work performed in monkeys and rats, we had proposed that the functional maturation of direct entorhinal cortex projections to the CA1 field of the hippocampus might underlie the emergence of basic allocentric spatial memory. We also proposed that the protracted development of the dentate gyrus and its projections to the CA3 field of the hippocampus might underlie the development of high-resolution allocentric spatial memory capacities, based on the essential contribution of these structures to the process known as pattern separation. Here, we present an experiment designed to assess the development of spatial pattern separation capacities and its impact on allocentric spatial memory performance in children from 18 to 48 months of age. We found that: (1) allocentric spatial memory performance improved with age, (2) as compared to younger children, a greater number of children older than 36 months advanced to the final stage requiring the highest degree of spatial resolution, and (3) children that failed at different stages exhibited difficulties in discriminating locations that required higher spatial resolution abilities. These results are consistent with the hypothesis that improvements in human spatial memory performance might be linked to improvements in pattern separation capacities.
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Launched by representatives from the Union démocratique du centre (UDC) with the aim of circumventing political and judicial decisions made at both local and national levels, the 2009 federal popular initiative calling for a ban on the construction of minarets rekindled the stigmatisation of Muslims living in Switzerland. Within the prevalent institutional configuration it moreover revived controversies surrounding issues such as direct democracy versus fundamental rights, or "the will of the people" versus "the power of the judges", whether national or international. "Judicialisation" is a polysemous concept. It is not understood here as the transfer to the courts of matters of political significance - in this instance the public regulation of religion - but as a process of juridification (or juridicalisation) in which court rulings were constantly anticipated in the political debate provoked by the popular initiative.
Resumo:
Overall Equipment Effectiveness (OEE) is the key metric of operational excellence. OEE monitors the actual performance of equipment relative to its performance capabilities under optimal manufacturing conditions. It looks at the entire manufacturing environment measuring, in addition to the equipment availability, the production efficiency while the equipment is available to run products, as well as the efficiency loss that results from scrap, rework, and yield losses. The analysis of the OEE provides improvement opportunities for the operation. One of the tools used for OEE improvement is Six Sigma DMAIC methodology which is a set of practices originally developed to improve processes by eliminating defects. It asserts the continuous efforts to reduce variation in process outputs as key to business success, as well as the possibility of measurement, analysis, improvement and control of manufacturing and business processes. In the case of the Bottomer line AD2378 in Papsac Maghreb Casablanca plant, the OEE figures reached 48.65 %, which is below the accepted OEE group performance. This required immediate actions to achieve OEE improvement. This Master thesis focuses on the application of Six Sigma DMAIC methodology in the OEE improvement on the Bottomer Line AD2378 in Papsac Maghreb Casablanca plant. First, the Six Sigma DMAIC and OEE usage in operation measurement will be discussed. Afterwards, the different DMAIC phases will allow the identification of improvement focus, the identification of OEE low performance causes and the design of improvement solutions. These will be implemented to allow further tracking of improvement impact on the plant operations.
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In the literature survey retention mechanisms, factors effecting retention and microparticles were studied. Also commercial microparticle retention systems and means to measure retention were studied. Optical retention measurement with RPA and Lasentec FBRM was studied. The experimental part contains study of different cationic polyacrylamides, anionic silica, bentonite and new generation micropolymer. In these studies the dosage, dosing order and dosing history were changing factors. The experimental work was done with RPA-apparatus with which, the retention process can be followed in real time. In testing was found that silica yielded better retention, when dosed nontraditionally before the polymer. Also silica was very dependant on the polymer dosage. With bentonite good colloidal retention was achieved with relatively low doses. Unlike silica bentonite was not dependant on polymer dosage. The relation of bentonite and polymer dosage is more defining when high retention is wanted. With 3-component systems using bentonite very high retention was achieved. With silica no improvement in retention was found in 3-component systems compared to dual component systems.