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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mätsystemanalys för kontrollmätning av stiftshåldiameter på en borrkrona

Gallego, Julio January 2016 (has links)
Detta examensarbete har utförts på Sandvik Mining and Construction Tools AB (SMC) och hade som uppdrag att införa arbete med statistisk processtyrning (SPS) vid en produktionscell. Innan implementering av SPS tekniker krävs det en säkerställning av mätsystemets tillförlitlighet. Målet med arbetet är att genom en mätsystemanalys (MSA) utvärdera den befintliga mätmetodens duglighet och erbjuda berörd personal vid SMC en ny mätmetodsmodell om den befintliga mätmetoden fallerar. Metoden som användes för att utföra MSA var en fallstudie. Analysen genomfördes med hjälp av olika förbättringsarbetssätt inom Sex sigmas metodik som till exempel DMAIC-förbättringscykel och fiskbensdiagram. Underlagen för studien baserades på kvantitativa- och kvalitativa data. Insamling av kvantitativa data utfördes med hjälp av strukturerade observationer medan kvalitativa data samlades in med hjälp av en nulägesanalys, individuella intervjuer, benchmarking och litteraturstudie. Arbetet består av 3 analyser utförda på två olika mätsystem. Resultatet pekade på att de befintliga mätsystemen inte var tillförlitliga nog för att kunna användas i produktionen hos SMC. Mätsystem 1 (mätmaskinen) exkluderades från vidare analyser på grund av tidsbrist för att kunna genomföra förbättringar på det. Mätsystem 2 gick igenom en förbättringsfas där flera grundorsaker till variationer i processen analyserades och förbättrades. Dessvärre blev mätsystemet fortfarande odugligt för att användning i produktionen. Med hjälp av matematiska och statistiska beräkningar fastställdes det att mätmaskinen är det lämpligaste mätsystem att använda inom produktionen hos SMC. Det kan betyda att mätsystemets acceptans är beroende av mätinstrumentet. / This essay has been carried out at Sandvik Mining and Construction Tools AB (SMC). The purpose of study was to introduce the statistical process control methodology (SPC) at the actual production cell. Before the implementation of SPC-techniques, it is required an analysis to ensure the measurement systems reliability. The objective of the work is that through a measurement system analysis (MSA) evaluate the existing measurement method capability and provide the relevant personnel at SMC with a new measurement model if the existing measurements methods fails.   The method used to perform the MSA was a case study. The analysis was performed using various improvement works within Six-Sigma methods such as DMAIC improvement cycle and fishbone diagram. The study was based on quantitative and qualitative data. Collection of quantitative data was performed using structured observations while qualitative data was assembled by means of a situation analysis, individual interviews, benchmarking and a literature review. The work consists of three studies performed on two different measurement systems.   The results indicated that the existing measurement systems were not reliable enough to be used in the SMC production. Measuring system 1 (measuring machine) were excluded from further analysis because of insufficient time to carry out improvements on it. Measuring system 2 went through a development phase where several causes of variations in the process were analyzed and improved. Unfortunately, the measurement system was still unfit for use in production.   With the help of mathematical and statistics calculations, it was determined that the measuring machine is the most appropriate measurement system to use in the SMC production process. This could mean that the measurement system acceptance is dependent on the measuring instrument
2

Aplikace statistické regulace procesu na nový produkt / The aplication of the statistical process control on the new product

Ježková, Kateřina January 2008 (has links)
The thesis is concerned with the aplication of the statistical process control on the new product and it provides proposals to its improvement in Plastik, s.r.o.
3

Measurement System Analysis : For Battery Production Using DMAIC at Northvolt AB

Nguyen, Phuc, Sahlberg, Adam January 2020 (has links)
As battery manufacturing is enclosed with multiple quality and safety requirements, the batteryindustry needs adequate Measurement Systems (MS) to provide high product quality and ensure a safe working environment. The study purpose was to improve the performance of an MS for battery production by utilizing MSA and Six Sigma methodology, and to make appropriate recommendations for improvement and future control. The study included 28 measurement instruments which were evaluated by the utilization of a framework consisting of five different errors identified in the literature, namely bias, linearity, stability, reproducibility and repeatability. This framework is considered as the theoretical contribution of this study. The improvement methodology DMAIC (Define-Measure-Analyze-Improve-Control) was used to perform the case study. The results indicate an overall improved MS and generated improvement suggestions of three recurrent scenarios that arose in the analysis. Moreover, a company adopted control plan with an intention to serve as a basis for future work within MSA is presented and concerns the practical contribution of this work. The results provide helpful support as well as establish a foundation of how to maintain a well-performing MS for Northvolt. By implementing the suggested recommendations, the potential saving was estimated to 395 000 SEK annually. / En mätsystemanalys genomfördes hos batteritillverkaren Northvolt. Då batteriproduktionomgärdas av flera kvalitets- och säkerhetskrav behöver batteriindustrin tillförlitliga mätsystem för att generera hög produktkvalitet samt upprätthålla en säkerhet för användare. Studien syftade till att förbättra prestandan hos ett mätsystem inom batteriproduktion genom användandet av mätsystemanalys och Sex Sigma-metodik, samt att ge lämpliga rekommendationer för förbättringar och framtida kontroll. Studien inkluderade 28 mätinstrument som utvärderades genom användningen av ett ramverk bestående av fem olika mätsystemfel identifierade i litteraturen, nämligen bias, linearity, stability, reproducibility och repeatability. Detta ramverk betraktas som det teoretiska bidraget från denna studie. Förbättringmetodiken DMAIC (Define-Measure-Analyze-Improve-Control) användes för att utföra fallstudien. Resultaten visar på ett övergripande förbättrat mätsystem och genererade förbättringsförslag på tre återkommande scenarier som uppstod i analysen. Dessutom presenteras en företagsanpassad kontrollplan med avsikt att utgöra en grund för framtida arbete inom mätsystemanalys och ses det praktiska bidraget från denna studie. Resultaten förblir ett användbartstöd samt skapar en grund för hur Northvolt upprätthåller ett högpresterande mätsystem. Genom att säkerställa prestandan av mätsystemet uppskattades den potentiella besparingen till 395 000 SEK årligen.
4

CONTROLE DA QUALIDADE DA INDUSTRIALIZAÇÃO DO IOGURTE SEM CONSERVANTE COM A APLICAÇÃO DA FERRAMENTA APPCC / QUALITY CONTROL OF YOGURT INDUSTRIALIZATION WITHOUT CONSERVATION WITH THE APPLICATION OF THE APPCC TOOL

Stein, Márcia 05 August 2005 (has links)
With the purpose of verifying the quality of industrialization of yogurt without artifivcial preservatives with fruit pulp it was decided to use the Analysis of Risks and Critical Control Points, APPCC in SETREM agro industry. The work has started with an APPCC group first constitution were, hen in a second moment established the risks and ways of prevention. Subsequently, the points to be controlled and the points that demonstrate greater risk incidence were determined, the ones called priorities, the critical points of control that the critical limits determined. For the critical limits the control procedures had been established among them the statistics was used carrying out the statistical process control in temperature control during the fermentation of the yogurt where from the superior and inferior limits the control letters were built to follow the process. In order to verify the efficiency of the equipment and operators the application of the Measurement System Analysis (MSA) in ten yogurt samples during the determination of pH-gâmetro. Later wasandyzed necessary corrective actions were delimited to be applied in apply wag lines of the critical limits. Some procedures verification for proper system APPCC were needed, that is, procedures in addition to those used in the control to demonstrate if the system APPCC is being efficient. With the application of the tools, the guarantee of the quality of the final product was gotten decreasing the necessity of the finished product inspections / Com a finalidade de verificar a industrialização do iogurte sem conservante com polpa de fruta, com qualidade, é que se decidiu empregar a ferramenta de Análise de Perigos e Pontos Críticos de Controle, APPCC, na agroindústria/SETREM. O trabalho iniciou com a constituição da equipe APPCC, a qual inicialmente se estruturou para num segundo momento levantar os perigos e medidas preventivas. Subseqüentemente, determinaram-se os pontos a serem controlados e os pontos que demonstram maior incidência de risco, os assim chamados prioritários, os pontos críticos de controle, para os quais determinou-se os limites críticos. Para os limites críticos foram estabelecidos os procedimentos de monitoração entre os quais utilizou-se da estatística, realizando-se o controle estatístico de processo no controle da temperatura durante a fermentação do iogurte sem conservante com polpa de fruta onde, a partir dos limites superiores e inferiores, construíram-se os gráficos de controle. Para verificar a eficiência do equipamento/operador, utilizou-se a aplicação da análise do sistema de medição, MSA, em dez amostras de iogurte durante a determinação do pH, com a utilização do pH-gâmetro. Posteriormente, delimitaram-se as ações corretivas necessárias a serem aplicadas nos desvios dos limites críticos. Também foram necessários alguns procedimentos de verificação para o próprio sistema APPCC, ou seja, utilizaram-se procedimentos em adição àqueles aplicados na monitoração para evidenciar se o sistema APPCC está sendo eficaz. Com a aplicação da ferramenta, obteve-se a garantia da segurança do produto final, diminuindo-se a necessidade de testes dos produtos acabados
5

Návrh postupu kontroly vybraných součástí revolveru / Design of inspection procedure for selected revolver components

Úlehlová, Eva January 2020 (has links)
The goal of this master’s thesis was design of the inspection procedure for hammer and trigger of the specific revolver model. Thesis was developed in cooperation with the manufacturer of the revolvers. The theoretical part deals with the MSA methodology, which is used to assess acceptability of measurement systems. The practical part describes the current measurement system and performs gage repeatability and reproducibility study. It was confirmed that the current measurement system requires improvement. Subsequently coordinate systems were designed, based on functional features of the hammer and trigger. Automated optical measurements, based on the coordinate systems, were performed. The results from these measurements were again assessed by the gage R&R study. The analysis confirmed improvement of acceptability of the designed measurement systems. Based on these results, it is recommended to apply suggested procedures in practice. Results and recommendations of this master’s thesis can contribute to develop metrology in the company and improve the existing measurement system.
6

Analýza systému měření / Measurement system analysis

Nezdařilíková, Martina January 2013 (has links)
Aim of the thesis is suggestion of Measurement system analysis for a company in the automotive industry. There were made an analysis of requirement of ČSN EN ISO 9001 and ČSN P ISO/TS 16949. Next there are procedures for various measurement system analysis. There are camparison between company and standart’s requirements. Then there are choosen suitable method for measurement system analysis.
7

Ensuring high-quality production during commissioning and ramp-up : A case study at Northvolt

Eklund, Henrik, Engström, Jacob January 2021 (has links)
Rechargeable lithium-ion batteries (LIBs) have generated a shift in the automotive industry towards electric vehicles (EVs) instead of vehicles powered by fossil fuels. As a result, the demand for LIBs is only expected to grow in the future due to an increased demand for passenger EVs. Consequently, LIB manufacturers have to increase their production to meet the increasing demand. Northvolt is a Swedish LIB manufacturer founded in 2016, aiming to start the production of LIBs at the Northvolt Ett factory in Skellefteå during 2021. The Northvolt Ett factory will be one of the largest battery plants in Europe, supplying battery cells for both commercial and domestic use. Poorly manufactured battery cells can potentially cause hazardous events, such as fires or explosions, further supporting the need for high quality batteries. Consequently, requirements from customers and industry standards are high in terms of product quality control through e.g. measurement system analysis (MSA), statistical process control (SPC), and capability analysis. Furthermore, previous research has highlighted issues during commissioning and ramp-up of production, potentially occurring at Northvolt Ett.  The purpose of this study has been to describe how high-quality production can be ensured and maintained during and after commissioning. The study has been conducted as a qualitative case study at Northvolt Ett, focusing on qualification of the coating process. The basis for the study was to examine previous research on quality assurance from other industries, analyze automotive standards, and gather learnings from the pilot production at Northvolt Labs in Västerås. Unstructured interviews were conducted with Northvolt staff to understand what had previously been done related to quality assurance for Coating.  The learnings from Northvolt Labs highlighted a clear focus on preventive actions, such as establishing a Design-FMEA, Process-FMEA, and a Control Plan for the coating process. However, room for improvement was identified in terms of process improvement and control, since the lack of SPC has yielded unreliable results from the performed capability analysis. In addition, previous research has shown that preventive actions should be combined with actions for process improvement to reach full-scale production quickly. Thus, recommendations have been made for Northvolt to implement a clear strategy for product qualification through SPC and capability analysis, as a complement to the preventive actions. The recommendations include specific propositions for validation of the coating process and a general framework for process validation through MSA, SPC, and capability analysis. The presented recommendations can help Northvolt perform successful commissioning of the processes at Northvolt Ett and can also be useful for process validation in other manufacturing industries. / Laddningsbara litium-jon-batterier (LIB:s) har skapat en omställning i bilindustrin mot eldrivna fordon istället för fordon som drivs av fossila bränslen. Som en konsekvens väntas efterfrågan av LIB:s bara att öka i framtiden på grund av en ökad efterfrågan på eldrivna passagerarfordon. LIB-tillverkare måste därför öka sin produktion för att möta den växande efterfrågan. Northvolt är en svensk LIB-tillverkare som grundades 2016, med sikte på att starta produktionen av LIB:s vid fabriken Northvolt Ett i Skellefteå under 2021. Fabriken Northvolt Ett kommer att vara en av de största batterifabrikerna i Europa och leverera battericeller för både kommersiell och privat användning. Dåligt tillverkade battericeller kan potentiellt orsaka allvarliga händelser som bränder eller explosioner, vilket vidare stödjer behovet av batterier med hög kvalitet. Till följd av detta är kraven från standarder och tillverkare inom bilindustrin höga i termer av kvalitetskontroll av produkter genom t.ex. mätsystemanalys (MSA), statistisk processtyrning (SPS), och duglighetsanalys. Vidare visar tidigare forskning på problem som kan uppstå under driftsättning och upprampning av produktion, vilka potentiellt kan uppstå för Northvolt Ett.  Syftet med denna studie har varit att beskriva hur högkvalitativ produktion kan säkerställas och upprätthållas under och efter driftsättning. Studien har genomförts som en kvalitativ fallstudie vid Northvolt Ett med fokus på kvalifikation av coating-processen. Utgångspunkten för studien har varit att undersöka tidigare forskning inom kvalitetssäkring från andra industrier, analysera standarder från bilindustrin, och hämta in lärdomar från pilotproduktionen vid Northvolt Labs i Västerås. Ostrukturerade intervjuer genomfördes med anställda på Northvolt för att öka förståelsen för vad som tidigare gjorts relaterat till kvalitetssäkring för Coating.  Lärdomarna från Northvolt Labs visade ett tydligt fokus på förebyggande åtgärder, som upprättande av en Design-FMEA, Process-FMEA, och en kontrollplan för coating-processen. Dock identifierades ett förbättringsområde inom åtgärder för processförbättring och kontroll, då avsaknaden av SPS har genererat opålitliga resultat från den genomförda duglighetsanalysen. Vidare har tidigare forskning visat att förebyggande åtgärder borde kombineras med åtgärder för processförbättring för att snabbt uppnå fullskalig produktion. Rekommendationer har därför tagits fram till Northvolt för att implementera en tydlig strategi för produktkvalifikation genom SPS och duglighetsanalys, som ett komplement till de förebyggande åtgärderna. Dessa rekommendationer inkluderar specifika förslag för validering av coating-processen samt ett generellt ramverk för processvalidering genom MSA, SPS, och duglighetsanalys. De presenterade rekommendationerna kan hjälpa Northvolt att genomföra en framgångsrik driftsättning av processerna på Northvolt Ett och kan även vara användbara för processvalidering i andra tillverkningsindustrier.
8

Zvýšení efektivity kontroly ramene tankovací nádrže

Sobotková, Kateřina January 2019 (has links)
The diploma thesis consists of a new design of a controlling procedure for a plastic component of a tank. Its theoretical part deals with the potential sources of errors and uncertainties arising from the measuring itself. It also deals with the characteristics of available CMM devices and includes an analysis of the methods assessing the acceptability of the measurement plan. The practical part analyses systematically the current state and proposes a new solution using a program created using a coordinate machine. A comparison of both variants is presented as an output of the thesis.
9

Automatizované měření asynchronního motoru pomocí LabVIEW / Automatic measurement of induction machine using LabVIEW

Halfar, Lukáš January 2016 (has links)
The main purpose of the thesis Automatic measurement of induction machine using LabVIEW was to develope an automated measuring system, which is used to perform tests of induction motors. The algorithm of the system is programmed in LabVIEW. In the practical part of this thesis, a measurement of the motor Atas Elektromotory Náchod a.s. T22VT512 is carried out, in order to verificate functions of the algorithm, and to perform tests of the motor to analyse losses. Another part of the work is dedicated to the electromagnetic calculation of the motor T22VT512. For this purpose, two softwares with different principles of calculation have been used. Firstly, the calculation is solved by an analytical based software called RMxprt. Secondly, the software Maxwell 2D is used to make the calculation of electric and magnetic fields by the finite element method.
10

Alla vill varandras väl : Hur ledarskap genom medarbetarskap i en kvalitetskultur skaparpatientnöjdhet vid svenska sjukhus

Franzén Ähdel, Carina, Bulukin Wilén, Frida January 2019 (has links)
Engagerat ledarskap är grunden till att skapa en god kvalitetskultur och för attlyckas krävs medarbetarskapets delaktighet. Forskare menar att stödet förnärvarande ledare i vården har fram tills idag varit tämligen outvecklat. Syftetmed denna studie var att förstå framgångsfaktorer för hur kvalitetskulturen isvensk sjukvård kan kopplas mot ledarnas möjlighet att främja ett gottmedarbetarskap. Detta utifrån en förklarande sekventiell mixad metod med tvåkvantitativa mätningar som slutligen resulterade i en kvalitativ intervju. Enmätning av kvalitetskulturen vid svenska sjukhus utfördes utifrån ett tidigareframtaget mätinstrument för att mäta kvalitetskultur. Mätinstrumentetpresenterades genom 13 beteendepar som främjar respektive hindrar enkvalitetskultur. Denna mätning visade att det idag råder en generellt godkvalitetskultur vid svenska sjukhus. Genom denna mätning kunde enregressionsanalys utföras som kopplades samman mot sjukhusens resultat iNationell patientenkät. Ett statistiskt signifikant beteende kunde uppmätassom enligt denna mätning skapar nöjdare patienter ju mer medarbetarnaupplever att detta beteende förekommer i deras organisation. Beteendet ärnär vi har ett problem tar vi reda på grundorsaken innan vi beslutar om enlösning. Detta beteende togs med till två framgångsrika sjukhus för att djupareförstå hur dessa arbetar med medarbetarskapet i just detta beteende. Utifrånworkshop med dessa två sjukhus är slutsatsen att ledare behöver ha erfaritden kvalitetskultur och det medarbetarskap de ska bära för att främja ettmedarbetarskap som kopplats samman med kvalitetskulturen. I jakten på attnå framgång är en stark kvalitetskultur eftersträvansvärd men utifrånworkshoparna ser författarna ingen möjlig snabb lösning för att nå dit.Resultatet visar att dagens ledare i vården behöver stöd i form av mentor ellerreflektion kring ledarskap själv eller i grupp för att utvecklas. I konstruktiv andaär det med förbättringskunskap i grunden som allas delaktighet i arbetet medständiga förbättringar bedrivs. Detta kräver allas reflektion, ärlighet, mod,öppenhet och förtroende där allt grundar sig i att alla vill varandras väl! / Committed leadership is the foundation for creating a good quality culture andto succeed, the participation of employees is required. Researchers argue thatsupport for the current leaders in healthcare has until now been ratherundeveloped. The purpose of this study was to understand how the qualityculture in Swedish healthcare can be linked to the leaders' ability to promotegood co-workership. This study was based on an explanatory sequentialmixed method with two quantitative measurements that ultimately resulted in aqualitative interview. A measurement of the quality culture at Swedishhospitals was taken based on a previously developed instrument formeasuring quality culture . The measuring instrument comprises 13behavioral pairs that promote or hinder a quality culture. This measure showsthat there is generally a good quality culture at Swedish hospitals at present.Through this measurement, a regression analysis was done which links to thehospital's results in the National Patient Survey. A statistically significantbehavior was observed, and according to this measurement, is likely to createmore satisfied patients as more professions feel that this behavior occurs intheir organization. The behaviour in question can be described as: when wehave a problem, we find out the root cause before we decide on a solution.This behavior was brought into two successful hospitals in order to understandmore deeply how they work with the co-workership in this particular behavior.Based on the workshop with these two hospitals, we conclude that leadersneed to have experienced the quality culture and the co-workership they areassumed to carry in order to promote an employee culture that is linked to thequality culture. In pursuit of success, a strong quality culture is desirable, butbased on the workshops, the authors see no possible quick solution to reachit. The result shows that today's leaders in healthcare need support in the formof a mentor or time for reflection on leadership on their own or in groups inorder to develop. In constructive approach, it is with improvement knowledgethat everyone's involvement in the work of continuous improvement isconducted. This requires reflection, honesty, courage, openness and trustfrom everyone involved and intentions rooted in the wellness and prosperity ofall. / <p>2019-06-27</p>

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