EVALUATING CHALLENGES, BENEFITS, AND DEPENDABILITY OF VIRTUAL AND PHYSICAL TESTING OF EMBEDDED SYSTEMS SOFTWAREAlhasan, Wahaab January 2022 (has links)
Software testing is a widely used quality assurance activity and often starts from the early development stages. However, starting early in the development process raises difficulties and challenges practitioners must deal with; most typically, hardware is not available in the required quantities, and there is the risk of damaging the hardware while testing. Emulating the physical hardware into virtual versions is a popular approach to overcome the mentioned obstacles. This master thesis, carried out at Westermo AB, investigates the differences between the physical and virtual hardware used for embedded system software testing and the possible benefits of combining both hardware versions in a hybrid system. Investigating differences between the hardware options helps identify which type of tests are more suitable in physical versus virtual hardware. The selected method for this thesis is a case study, starting with a pre-study phase investigating how other industries tackle the difficulties and challenges mentioned. Further, data were collected from two sources, historical test reports, and a questionnaire. The historical test reports showed a timing difference between virtual and physical hardware. The reset process of physical hardware is often faster than virtual hardware, but the link-up/link-down time is slower in physical hardware. The questionnaire also confirmed the timing differences as a significant challenge often experienced by engineers. Another challenge highlighted by the questionnaire answers is that "false positives" are typically caused by virtual hardware, where issues do not always turn up due to the virtual nature of communication. Another difference proven from this thesis is that virtual hardware is more failure-prone during the early stages of testing than physical hardware. The hybrid system could be advantageous in various ways, such as quantitatively expanding the current test systems and increasing test coverage. Future work could contribute with a proof-of-concept implementation of the hybrid system to confirm the advantages and demonstrate the third option of a test system.
Bernström, David, Nyström, Erik
A Remotely Operated underwater Vehicle (ROV) faces many problems regarding dependability and most issues come during launch and recovery. The thesis looks at finding what dependability aspects shall be considered when developing a modular ROV to come up with recommendations for a system, together with a more reliable method of launching and recovering ROV’s. The area is important since it has been shown that there exists a gap in the market regarding multipurpose and dependable ROV’s. The method used in the thesis is a case study starting with a literature study to get a solid foundation to be able to conduct interviews. The interviews were structured as a semi-structured interview and the data were used to be able to find the important dependability aspects to give out a recommendation of a ROV system. The result shows the different dependability aspects that should be emphasised to ensure a safe system: Reliability, safety, confidentiality, maintainability, availability and integrity. From the recommendation, a simulation was conducted to test the stabilizing force to increase the reliability of launch and recovery. Furthermore, the different tests show that the amount of motion can be lowered by using thruster force as well as adding weight to the system. From the results it can be determined that the use of tether tension as a stabilizing factor is possible by using Dynamic Positioning (DP) to control the ROV’s thrusters to increase reliability.
MÄTVERKTYG OCH MÄTNING AV LOGISTIKENS EFFEKTIVITET INOM BYGGBRANSCHEN : Mätning av logistikeffektiviteten inom byggproduktionEl Masry, Sheila January 2022 (has links)
Logistics is a talked about but also difficult to define concept as this concept has several different interpretations. Actually, logistics is primarily about more efficient material flows, which in turn should create more efficient work processes in production. In literature research, knowledge has been sought about efficient logistics and lean, which in turn led to investigating the various areas and factors that lead to waste. Logistics within the construction industry, and not least production, is today an area that is well debated and is one of the more important aspects to achieve more efficient production. Based on the knowledge gathered, a measurement tool has since been developed which is intended to be used within construction production to measure the actual efficiency of logistics. This means that the tool can, if desired, be used in more projects than those processed and treated in this scientific report. This scientific report will answer the following questions: 1. What shortcomings are found in logistics in the construction industry 2. Are there one or more widespread deficiencies? 3. Develop a measurement tool that should be able to measure the efficiency of logistics in projects within construction production. The result shows that with well-planned logistics, more efficient logistics can be achieved and thus profit can be achieved in the form of both time and money. This scientific report will provide an insight into the field of logistics during construction production. Furthermore, the work will highlight the shortcomings that appear in the efficiency of logistics within the investigated projects and give suggestions on how this can be remedied.
Kundupplevelse av tjänstekvalitet genom säljprocessen : En fallstudie på ett B2B-företag inom solcellsbranschenSvensson, Jennifer, Hansson, Anna January 2023 (has links)
Purpose – The demand for solar cells has increased, creating challenges for solar cell suppliers operating in a B2B context. Customers should be central to all companies, which is why it is important to examine their experience of service quality through the sales process of solar cell suppliers. Thus, the purpose of this study is: To identify improvement opportunities for solar cell suppliers’ sales process based on customers’ experiences from a service quality perspective. Based on the purpose, two research questions were formulated:  What strengths and weaknesses do customers perceive that solar cell suppliers' salesprocess have from a service quality perspective?  How can solar cell suppliers' sales process be improved from a service quality perspective? Method – The study is a case study, where data was collected from a selected case company and ten of their business customers. To be able to map out the case company's sales process, a document study, and an open interview with employees at the case company were carried out. Based on the collected data, interview questions were created for ten of the case company's business customers. Ten semi-structured interviews were conducted to identify the customers' experience of service quality through the sales process, whereupon suggestions for improvement could be identified. Results – The identified strengths meant a high experience of service quality according to the customers. The strengths were professional treatment, effective communication, detailed planning, well-executed execution as well as detecting and resolution of problems. The shortcomings identified through the sales process resulted in an experience of low service quality according to the customers. The shortcomings were slow response, overworked staff, lack of project management, inadequate material delivery, delayed projects, visualization problems and deficiencies in detecting defects. The main improvement proposal is to create a plan with instructions for who is responsible for collecting and transferring information between involved parties. Implications – By creating a plan for the collection and transferring of information, where it becomes clear who has responsibility between both internal and external parties, the service quality through solar cell suppliers' sales process can increase. Technology that creates a seamless service is an important part of the sales process, whereupon developed and efficient technology is important from a long-term perspective. For example, customers can be involved in solar cell suppliers' IT systems to be able to obtain information. Limitations – The study is a single case study, which means that data was collected from only one company. In addition, only ten business customers have been interviewed to collect data. These aspects may indicate that the generalizability of the study can be questioned. Key words – Customer satisfaction, customer value, selling process, service quality, solar cell supplier
The railway track network is one of the major modes of transportation and among a country’s most valuable infrastructure assets. Maintenance and renewal of railway infrastructure have a vital role in safety performance, the quality of the ride, train punctuality, and the life cycle cost of assets. Due to the large proportion of maintenance costs, increasing the efficiency of maintenance through optimised planning can result in high amounts of cost-saving. Moreover, from a safety perspective, late maintenance intervention can result in defective track and rollingstock components, which in severe cases, can cause severe accidents such as derailments. An effective maintenance management system is required to ensure the availability of the infrastructure system and meet the increasing capacity demand. The recent rapid technological revolution and increasing deployment of sensors and connected devices created new possibilities to increase the maintenance strategy effectiveness in the railway network. The purpose of this thesis is to expand the knowledge and methods for planning and scheduling of railway infrastructure maintenance. The research vision is to find quantitative approaches for integrated tactical planning and operational scheduling of predictive condition-based maintenance which can be put to practical use and improve the efficiency of the railway system. First, a thorough literature review study is performed to identify improvement policies for maintenance planning and scheduling in the literature and also to analyse the current approaches in optimising the maintenance planning and scheduling problem. Second, a novel data-driven multi-level decision-making framework to improve the efficiency of maintenance planning and scheduling is developed. The proposed framework aims to support the selection of track segments for maintenance by providing a practical degradation prediction model based on available condition measurement data. The framework considers the uncertainty of future predictions using the probability of surpassing a maintenance limit instead of using the predicted value. Moreover, an extensive total maintenance cost formulation is developed to include both direct and indirect preventive and corrective costs to observe the effect of using cost optimisation and grouping algorithms at the operational scheduling level. The performance of the proposed framework is evaluated through a case study based on data from a track section of the iron ore line between Boden and Luleå. The results indicate that the proposed approach can lead to cost savings in both optimal and grouping plans. This framework may be a useful decision support tool in the automated planning and scheduling of maintenance based on track geometry measurements.
Process plants come with a wide variety of engineering challenges. Each process has uniqueoperating conditions that require careful operation and maintenance programs to keep the process equipment in a condition that is safe for operation. A pilot-scale plant was built in Luleå to demonstrate the possibility of carbon dioxide removal from blast furnace gas usingthe Sorption Enhanced Water Gas Shift (SEWGS) technology. One of the challenges facingthe SEWGS pilot plant was the lack of a maintenance plan which was the motivation for this thesis. The aim of this thesis was to create a maintenance plan for the SEWGS pilot plant. Studying the process conditions of the pilot plant was the starting point since an understanding of the unique operating conditions was necessary for creating a maintenance plan for the pilot plant’s equipment. The Reliability-centered maintenance (RCM) method was chosen to create the maintenance plan. The study began with determining the objectives and contents of the analysis. The next step was a functional failure analysis in the form of a Failure Mode and Effect Criticality Analysis (FMECA) covering all the equipment in the plant. Afterwards the failure consequences were assessed based on a criticality assessment matrix to determine which equipment necessitate the performance of maintenance activities. The maintenance plan was created based upon the criticality of the equipment and the selected maintenance activities were based on the recommendations of manufacturers. The failure analysis found that the blast furnace gas compressor is the most critical for the process. The boiler and superheater have been found to be highly critical due to the dangerous safety consequences of their failure. In addition, all pressure safety valves have been found to be highly critical due to the hidden nature of their failure. The maintenance plan addresses these critical items and other less critical items while some non-critical items have been removed from the plan due to the negligible consequences of their failure.
Can reliability centered maintenance foster asset management? : A case study at the process-oriented steel company OutokumpuJonsson, Niklas January 2022 (has links)
No description available.
Håkansson, Anton, Lundgren, Jan
Företaget Xylem Flygt i Emmaboda producerar dränkbara pumpar av olika storlek och typer som används i hela världen. Innan pumparna levereras till kund testas de i Xylem’s egna testanläggningar. Anläggningen Q2 som berörs i rapporten består av en bassäng med tillhörande rörsystem, ventiler, anslutningsutrustning och mätutrustning. Denna rapport undersöker och lägger fram förslag på förbättringsmöjligheter rörande testanläggningens underhållsplanering. Frågor som undersöks är, om anläggningen ser kvalitetsmässigt och utseendemässigt riktigt ut inför kundbesök, tidsintervaller mellan förebyggande underhåll, miljöansvar angående vattenbyte i bassäng, möjlighet att implementera resultatet på övriga anläggningar samt rekommendationer på uppföljning. Rapporten resulterade i checklistor till underhållsavdelning och operatörer av anläggningen, dokumentation av komponenter och förbättringsförslag. / The company Xylem Flygt in Emmaboda produces submersible pumps of various sizes and types used worldwide. Before the pumps are delivered to the customer they are tested in Xylem's own testing facilities. The plant Q2 concerned in the report consists of a basin with associated piping, valves, connection equipment and measurement equipment. This reports main objective is to investigate and make proposals for improvement regarding test facility maintenance planning. Other questions examined areIf the plants looks representable in quality and appearance to the visiting customers, the time intervals between preventive maintenance, environmental responsibility regarding the change of water in the basin, the ability to implement the results in other facilities as well as recommendations on follow-up’s. The report resulted in checklists for the maintenance department and the operators of the facility, documentation of components and improvement proposals.
Hur utvecklas förslagsystemet i en konsultverksamhet? : En studie av förbättringsarbete på PlantVisionMiefalk, Julia January 2019 (has links)
Genom att generera ständig förbättring kan en organisation vara konkurrenskraftig och fortsätta anpassa sig till en föränderlig värld. Förslagsystem är ett sätt att involvera hela organisationen i arbetet med ständiga förbättringar. Genom medarbetarna uppdagas idéer och förslag som är relevanta för den dagliga verksamheten och genererar inkrementella förbättringar som resulterar i utveckling och innovation. Syftet med studien var att undersöka hur förslagsystemet i ett konsultbolag kunde utvecklas för att hantera och organisera förbättring. Tidigare studier visar hur förslagsystem byggs på två organisatoriska pelare, företagskultur och företagsstruktur. För att kunna skapa en ändamålsenlig hantering och organisering av förbättringsförslag behövde därför både strukturella och kulturella aspekter av förslagsystemet undersökas. Studien initierades med att kartlägga fallföretagets förslagsprocess för att skapa en övergripande bild av den befintliga strukturen. Därefter togs de kulturella aspekterna i beaktning genom medarbetarnas uppfattningar av förbättringsarbetet och förslagsprocessen. Genom tematisk analys upprättades koder, faktorer och teman som redogör centrala områden för ett förslagsystem och dess framgång. De identifierade kulturella och strukturella aspekterna av förbättringsförslag användes sedan för att beskriva förslagsarbete i en ny modell. De rekommendationer som togs fram för fallföretagets fortsatta arbete ansågs till stor del påverka strukturen för förslagsystemet. Genom att formulera en målsättning som på ett enkelt sätt redogör syftet med organisationens förbättringsarbete skapas en förståelse för vad förbättringsarbetet önskar uppnå. Att reflektera kring organisatoriska förutsättningar samt hur engagemanget från ledning och medarbetare fungerar genererar förståelse för kulturella och strukturella aspekter som företaget har att förhålla sig till. Fallföretaget PlantVision, som konsultbolag, behöver särskilt undersöka hur de ska hantera timdebitering kontra förbättringsarbete för att medarbetarna ska motiveras att arbeta med båda. Timdebiteringen visade sig påverka medarbetarna i deras arbete med förbättringar då konsulter förväntas debitera arbetade timmar till kund och inte fokusera på interna förbättringar. Samtidigt måste organisationen fortsätta förbättras för att vara konkurrenskraftiga, och i en konsultverksamhet bör konsulterna involveras i förbättringsarbetet eftersom de har kontakten med kunden. Medarbetarna bör därför motiveras till att arbeta med en kombination av timdebitering och förbättringsarbete. Det är även värdefullt att analysera engagemanget för förbättringsarbete, både bland ledning och medarbetare för att kunna avgöra hur de ska fortsätta motiveras till att engagera sig i ständig förbättring. För att skapa ytterligare struktur i förbättringsarbetet upprättades ett nytt förslagsystem online som ett förslag på hur PlantVision kan hantera förbättringsförslag på ett effektivare sätt. Ett förslagsystem som främjar transparens och struktur samt ökar den interna kommunikationen mellan medarbetare och ledning antas medföra ett förbättringsarbete som drivs av medarbetarna. Studien visar på att konsultbolag har specifika förutsättningar som bör tas i beaktning vid upprättande och utvecklande av förslagsystem. I övrigt redogör studien hur målsättning, engagemang, transparens och struktur samt kommunikation bygger ett framgångsrikt förslagsystem och lägger grunden för inkrementellt förbättringsarbete.
Tillståndsövervakning av fjärrstyrda distribuerade frånskiljare i mellanspänningsnätet / Condition Monitoring of Remote Controlled Distributed MV DisconnectorsEriksson, William January 2019 (has links)
This thesis studied the possibilities to monitor disconnectors’ operating times to indicate when maintenance needs to be performed. The main hypothesis of this study was that the operational time in a disconnector manoeuvre, open or close, correlates with the resistance in the mechanical components. If the operational time deviates too much from the baseline duration, then this may indicate that the disconnector needs to be maintained. Five substudies were conducted to study if it was possible to monitor the operating time and if the logged operating times had been affected by external conditions. Together they illustrated it might be possible to monitor operating times, but this study cannot state it with certainty based on the available data. From the results, it was possible to see that normal operating times for disconnectors varied within a group of disconnectors of the same type and manufacturer. Why it differed within groups of the same type and manufacturer might be explained by the effects of external conditions. It was shown that a varying transfer time occurred when logging the operation times in the front end processor. Furthermore, the year of production of the disconnector affected the median operating time, but it did not affect the operating time in an intuitive way, that is the operating time did not get longer for older disconnectors. Also, the geographical position of the disconnector may affect the operating time. When these external conditions were considered, disconnectors were concluded necessary to be studied individually. If disconnectors would be studied individually condition monitoring might be possible, although, it is not possible at the moment because of the lack of observations per disconnector.
Page generated in 0.1213 seconds