Projektering vid renoveringsprojekt ser ofta väldigt olika ut och skiljer sig från projekteringen vid nyproduktion. Det är därför svårt att ta fram en mall eller standard för hur produktionen ska genomföras och avvikelser kan lätt uppstå.  Avvikelser som uppstår inom renoveringsprojekt kan visa sig vara väldigt tidskrävande eller i värsta fall leda till stopp inom produktionen och det ställs stora krav på projektörerna som måste ha goda kunskaper inom området.  Inom ramen för examensarbetet ingår att identifiera och analysera hur kritiska avvikelser inom renoveringsprojekt uppstår samt hur man ska göra för att hantera detta under ett tidigt skede av renoveringen. Som referensobjekt under examensarbetet används renoveringen av bostadsrättföreningen Kurortsparken i Nynäshamn. Rapporten kommer att analysera de avvikelser som uppstått under produktionen samt ge förslag för hur man kunde ha hanterat projektet och de avvikelser som uppstod annorlunda. / The planning for renovation projects often look very different and distinct from the planning for new production. It is therefore difficult to set up a template or standard for how the production will be implemented and variations may readily occur. Deviations that arise in renovation projects can prove to be very time consuming and worst lead to a stop in production and the concern results in the designer that must be experienced.  As part of the thesis is to find and analyze the critical differences in the renovation project and how to do to manage it during the early stages of renovation. As a reference point for the thesis is the renovation of the housing association Kurortsparken in Nynäshamn. The report will analyze the deviations that occurred during the production and to give suggestions for how to handle the project and the changes that occurred differently.

The power output at the Forsmark nuclear power plant sometimes deviates from the expected value. The causes of these deviations are sometimes known and sometimes unknown. Three types of machine learning methods (k-nearest neighbors, support vector machines and linear regression) were trained to predict whether or not the power deviation would be outside an expected interval. The data used to train the models was gathered from points in the power production process and the data signals consisted mostly of temperatures, pressures and flows. A large part of the project was dedicated to preparing the data before using it to train the models. Temperature signals were shown to be the best predictors of deviation in power, followed by pressure and flow. The model type that performed the best was k-nearest neighbors, followed by support vector machines and linear regression. Principal component analysis was performed to reduce the size of the training datasets and was found to perform equally well in the prediction task as when principal component analysis was not used.

he company in the study seek to work more sustainable by minimizing transportations. They aim to reduce their CO2 emissions by 50%, independently on sold volume, by 2030, with 2019 as the year of reference. This report is about Epiroc Rock Drill AB’s sustainability goals inspired by Agenda 2030 and how their process deviations result in unnecessary transportations that negatively affect the environment with CO2 emissions. Epiroc Rock Drills AB aspires to gain an understanding of which process deviations lead to unnecessary transports and how much CO2 emissions they generate. In order to fulfil the aspiration, a description of the current situation was formed in which it is possible to distinguish in which parts of Underground's processes need of transportations appear and why. An analysis of the current situation was then needed to be able to answer the question of what process deviations affect Underground’s transportation needs and how much CO2 emissions they generate. To determine how much CO2 emissions the process deviations generated, a quantification of the CO2 emissions that emerged from process deviations in 2019 was included in the current situation analysis. The conclusions from the thesis were that the areas of lack of quality, delayed material, warehousing, quality assurance and washing, scrapping and 90-kits cause process deviations and affect Underground's transport needs and CO2 emissions. Summarized, the areas generated 3332 tonnes of CO2 emissions. The areas of lack of quality, delayed material and 90-kits caused the greatest amount of CO2 emissions which amounted to 3169 tonnes. The work carried out has created a foundation that Underground can continue to work with in the area of transport to achieve the goal of halving their CO2 emissions. The next step is to work with the process deviations that has been presented to minimize or eliminate them. / Företaget i studien strävar efter att arbeta mer hållbart genom att bland annat minimera transporter. De har som mål att år 2030, oberoende av såld volym, halvera sina CO2-utsläpp i linje med Agenda 2030 med 2019 som referensår. Denna rapport handlar om Epiroc Rock Drills AB:s hållbarhetsmål inspirerade av Agenda 2030 och hur deras processlöserier medför onödiga transporter vilket påverkar miljön negativt med CO2-utsläpp. Epiroc Rock Drills AB önskar att få förståelse för vilka processlöserier som leder till onödiga transporter och hur mycket CO2-utsläpp de genererar. För att uppfylla önskemålet framställdes en nulägesbeskrivning i vilken det går att utläsa i vilka delar av Undergrounds processer ett behov av transporter uppstår och varför. Med nulägesbeskrivningen som grund identifierades processlöserier som påverkar Undergrounds transportbehov och hur stora CO2-utsläpp de genererar. För att veta hur mycket CO2-utsläpp processlöserierna genererade inkluderades en kvantifiering av CO2-utsläppen som uppstod av processlöserier 2019 i nulägesanalysen.   Slutsatserna från examensarbetet var att områdena kvalitetsbrist, försenat material, lagerhållning, kvalitetssäkring och tvättning, skrotning och 90-kit orsakar processlöserier och påverkar Undergrounds transportbehov samt CO2-utsläpp. Tillsammans genererade områdena 3332 ton CO2-utsläpp. Områdena kvalitetsbrist, försenat material och 90-kit orsakade störst mängd CO2-utsläpp och uppgick till 3169 ton. Arbetet som genomförts har skapat en grund som Underground kan fortsätta arbeta med inom området transport för att nå målet att halvera sina CO2-utsläpp till 2030. Nästa steg är att arbeta med de processlöserier som lyfts för att minska eller eliminera dem.

En central del i patientsäkerhetsarbetet inom hälso- och sjukvård är att personalen rapporterar risker och avvikelser som upptäcks i verksamheten. En avvikelse är ett faktum när verksamheten inte når upp till satta mål och krav utifrån lagar, föreskrifter och beslut och kan vara allt från småstrul som tar tid från patientarbete till en allvarlig skada som inträffar (SOSFS 2011:9) Att ständigt arbeta med förbättringar är ett måste för att anpassa verksamheten utifrån nya uppkomna behov krav och förutsättningar. Att ständigt identifierade brister och ta tillvara på medarbetares förslag till förbättring, samt sträva efter en samsyn är förutsättningar som krävs för att verksamheten ständigt ska förbättras. Studiens syfte var att undersöka hur man använder rapporterade avvikelser som underlag till att förbättra sin verksamhet samt vilka förutsättningar som krävs för att arbeta med avvikelser på ett systematiskt sätt. Studien utgörs av flervalsmetodforskning där data samlats in via semistrukturerade intervjuer med tre vårdenhetschefer inom en verksamhet för att få en fördjupad förståelse av förutsättningar och utmaningar med att använda avvikelser för att förbättra sin verksamhet. För att få en förstärkt och bredare bild av studiens frågeställningar kompletterades datainsamlingen med en enkät där 60 medarbetare inom fyra vårdenheter svarat. Empirisk data analyserades genom tematisk analys. I resultatet framkommer fem övergripande tema som både chefer och medarbetare identifierat som viktiga förutsättningar för att förbättra sin verksamhet med grund i avvikelser; Samsyn, Struktur, Chefens stöd, Lärande och Medarbetares delaktighet som även inkluderar fler underliggande identifierade subteman. Utmaningar identifierades som tre övergripande tema; Fokus på rätt sak, Prioritering av tid samt Integrera förbättringsarbetet i det dagliga arbetet. En av frågeställningarna handlade också om hur medarbetares förslag till förbättring fångas upp och resulterade i intressanta reflektioner både hos medarbetare och chefer. / A central aspect of patient safety work within healthcare is for the staff to report risks and deviations. A deviation occurs when healthcare fails to meet set goals and requirements according to laws, regulations, and decisions. It may include minor issues that take time away from patient, to serious incidents causing harm (SOSFS 2011:9). Continuous improvements are necessary to adapt the care unit based on new emerging needs and conditions. Constantly identifying shortcomings, make use of employees' improvement suggestions, and striving for consensus are prerequisites for continuous improvement in care units. This study aimed to investigate how reported deviations are utilized as a basis for improving operations, as well as the prerequisites for working with deviations in a systematic manner. The study was designed as a mixed-methods research design, with data collected through semi-structured interviews with three unit managers within a healthcare organization to gain an deepened understanding of the prerequisites and challenges associated with using deviations to improve care units. Data collection was complemented with a survey in which 60 employees from four units responded to enhance and broaden the understanding of the research questions. Empirical data were analyzed through thematic analysis. The results showed five overarching themes that both managers and employees identified as important prerequisites for improving operations based on deviations: Consensus, Structure, Managerial Support, Learning, and Employee involvement, including several underlying subthemes. Challenges were identified in three overarching themes: Focus on the right things, Time prioritization, and Integrating improvement work into daily operations. One of the research questions also focused on how employees' improvement suggestions are captured, resulting in interesting reflections among both employees and managers

Stochastic simulation has been widely applied in many domains. More recently, however, the rapid surge of sophisticated problems such as safety evaluation of intelligent systems has posed various challenges to conventional statistical methods. Motivated by these challenges, in this thesis, we develop novel methodologies with theoretical guarantees and numerical applications to tackle them from different perspectives. In particular, our works can be categorized into two areas: (1) rare-event estimation (Chapters 2 to 5) where we develop approaches to estimating the probabilities of rare events via simulation; (2) model calibration (Chapters 6 and 7) where we aim at calibrating the simulation model so that it is close to reality. In Chapter 2, we study rare-event simulation for a class of problems where the target hitting sets of interest are defined via modern machine learning tools such as neural networks and random forests. We investigate an importance sampling scheme that integrates the dominating point machinery in large deviations and sequential mixed integer programming to locate the underlying dominating points. We provide efficiency guarantees and numerical demonstration of our approach. In Chapter 3, we propose a new efficiency criterion for importance sampling, which we call probabilistic efficiency. Conventionally, an estimator is regarded as efficient if its relative error is sufficiently controlled. It is widely known that when a rare-event set contains multiple "important regions" encoded by the dominating points, importance sampling needs to account for all of them via mixing to achieve efficiency. We argue that the traditional analysis recipe could suffer from intrinsic looseness by using relative error as an efficiency criterion. Thus, we propose the new efficiency notion to tighten this gap. In particular, we show that under the standard Gartner-Ellis large deviations regime, an importance sampling that uses only the most significant dominating points is sufficient to attain this efficiency notion. In Chapter 4, we consider the estimation of rare-event probabilities using sample proportions output by crude Monte Carlo. Due to the recent surge of sophisticated rare-event problems, efficiency-guaranteed variance reduction may face implementation challenges, which motivate one to look at naive estimators. In this chapter we construct confidence intervals for the target probability using this naive estimator from various techniques, and then analyze their validity as well as tightness respectively quantified by the coverage probability and relative half-width. In Chapter 5, we propose the use of extreme value analysis, in particular the peak-over-threshold method which is popularly employed for extremal estimation of real datasets, in the simulation setting. More specifically, we view crude Monte Carlo samples as data to fit on a generalized Pareto distribution. We test this idea on several numerical examples. The results show that in the absence of efficient variance reduction schemes, it appears to offer potential benefits to enhance crude Monte Carlo estimates. In Chapter 6, we investigate a framework to develop calibration schemes in parametric settings, which satisfies rigorous frequentist statistical guarantees via a basic notion that we call eligibility set designed to bypass non-identifiability via a set-based estimation. We investigate a feature extraction-then-aggregation approach to construct these sets that target at multivariate outputs. We demonstrate our methodology on several numerical examples, including an application to calibration of a limit order book market simulator. In Chapter 7, we study a methodology to tackle the NASA Langley Uncertainty Quantification Challenge, a model calibration problem under both aleatory and epistemic uncertainties. Our methodology is based on an integration of distributionally robust optimization and importance sampling. The main computation machinery in this integrated methodology amounts to solving sampled linear programs. We present theoretical statistical guarantees of our approach via connections to nonparametric hypothesis testing, and numerical performances including parameter calibration and downstream decision and risk evaluation tasks.

The purpose of the thesis work was to look at the concept process and get an overview of the workflow for the concept initiation flow, including the offer- and order process, where the focus was on the concept part. The project was held at RBBP/RBBS, R&D Bus Body Department to follow the concept development team in Poland (DOL team). The objectives were to document an example for a specific concept, highlight deviations in the different processes and come up with recommendations for improvements. Methods in this project were: going through the documentation at Scania (the offer-, order- and concept process), observations by attending different meetings, interviews with people from different departments, visiting the bus production in Poland and comparing the information with scientific methods. The concept part resulted in a flowchart that reflects the picked concept process. Findings in this thesis work were that they didn’t follow the offer process, and for the concept part, the DOL team worked with a more traditional way of concept generation by just developing one proposal, and the designers didn’t always know the customer’s needs. Some recommendations were to update the offer process and use the “creative” way for concept generation as much as possible, an advantage for the DOL team would be if the costumer’s needs, not the technical requirement would be presented in the requirements specification for developing a concept with high quality and low costs. / Syftet med examensarbetet var att titta på konceptprocessen och få en överblick över arbetsflödet för konceptinitieringsflödet, inklusive offert- och orderprocessen, där fokuset låg på konceptdelen. Projektet utfördes på RBBP/RBBS R&D Bus Body Departement, för att följa konceptutvecklingsteamet i Polen (DOL teamet). Målen var att dokumentera ett exempel för ett specifikt koncept, lyfta fram avvikelser i de olika processerna och komma med några rekommendationer till förbättringar. Metoder i detta projekt var: gå igenom dokumentationen på Scania (offert-, order- och konceptprocessen), observationer genom att delta på möten, intervjuer med personer från olika avdelningar, besöka bussproduktionen i Polen och jämföra informationen med vetenskapliga metoder. Konceptdelen resulterade i ett flödesschema som speglar det utvalda koncepts process. Avvikelser som hittades i arbete var att de inte följde offertprocessen, och gällande konceptdelen använde DOL teamet det traditionella sättet att skapa koncept genom att bara ta fram ett förslag samt att konstruktörerna inte alltid kände till kundens behov. Några rekommendationer var att uppdatera offertprocessen samt att använda det "kreativa" sättet för konceptgenerering så mycket som möjligt, en fördel för DOL teamet skulle vara om kundens behov och inte det tekniska kravet skulle presenteras i kravspecifikationen för att utveckla ett koncept med hög kvalitet och lägre kostnader.

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There has been recent incentive for understanding the possible deleterious effects that manufacturing deviations can have on compressor blade performance. This is of particular importance in today's age, as compressor designs are pushing operating limits by employing fewer stages with higher loadings and are designed to operate at ever higher altitudes. Deviations in these advanced, as well as legacy designs, could negatively affect the performance and operation of a core compressor; thus, a numerical investigation to quantify manufacturing deviations and their effects is undertaken. Data from three radial sections of every compressor blade in a single row of a production compressor is used as the basis for this investigation. Deviations from the compressor blade design intent to the as-manufactured blades are quantified with a statistical method known as principle component analysis (PCA). MISES, an Euler solver coupled with integral boundary-layer calculations, is used to analyze the effects that the aforementioned deviations have on compressor blade performance when the inlet flow conditions produce a Mach number of approximately 0.7 and a Reynolds number of approximately 6.5e5. It was found that the majority of manufacturing deviations were within a range of plus or minus 4 percent of the design intent, and deviations at the leading edge had a critical effect on performance. Of particular interest is the fact that deviations at the leading edge not only degraded performance but significantly changed the boundary-layer behavior from that of the design case. / Master of Science

The master thesis The Influence of Photovoltaic Power Plants Disconnection During Frequency Deviations introduce reader to the theory of frequency regulation in the electric power system. The theoretical part introduces regulation reserve that are used by transmission system operator to balance power imbalances. In the next part is made introduction to the system state classification and knowledge of European Network of Transmission System Operators for Electricity about unsolicited disconnection of photovoltaic plants. The theoretical part of the recommendations and simulations is followed by a part of the work in which the analysis of the implementation of the frequency boundary in which the photovoltaic power plants are operated in selected states of synchronously interconnected Europe. The master thesis continues to explain the origin of power imbalances by introducing a theory of electricity trading. Deterministic frequency deviations are one of the causes of the occurrence of frequent imbalances in the system and are discussed in the following chapter together with a proposal for a possible solution. In the last part of the master thesis are presented simulations that were made to determine the impact of the speed control regulator in the Czech Republic on unsolicited disconnection of photovoltaic power plants.