Atlas Copco is a global Swedish industrial company that develops and manufactures handheld electric and air powered tools. Their customers can be found in the automotive and aerospace industries, industrial manufacturing and maintenance, as well as in vehicle service and maintenance. This bachelor's degree project examines the ability to increase the process efficiency of the company's factory in Tierp by expanding the ability to perform further testing of the tools that show deviations at the final test. Today, extensive testing of all assembled power tools is carried out in the factory before they are sent to the customer. When a deviation is detected, the tool is repaired by replacing components in a certain order. By expanding the troubleshooting methodology, the repair process can be shortened. Based on a comprehensive database a statistical analysis has been performed which shows that approximately 47% of the tools that are unable to meet quality standards have the same error code. Over 37% of these devices are repaired by replacing the main board of the tool. This study indicates that in many cases it is not the main board which is the cause, but errors in the assembly. Using root cause analysis, structured interviews, surveys, developed test protocols and test platforms, a number of factors have been identified that can contribute to increased process quality. The thesis proposes the introduction of an expanded test platform that can help repair technicians in their work. It also suggests a number of constructional changes in the tools that prevents incorrect assembles. / Atlas Copco är ett globalt svenskt industriföretag som bland annat utvecklar och tillverkar handhållna el- och tryckluftsdrivna verktyg för kunder inom fordons- och flygindustrierna, industriell tillverkning och underhåll, samt inom fordonsservice. Detta kandidatexamensarbete undersöker möjligheten att öka processeffektiviteten i företagets fabrik i Tierp genom att utöka möjligheterna att utföra ytterligare test av de verktyg som visar avvikelser vid sluttest. I fabriken genomförs idag omfattande tester av alla monterade elverktyg innan de skickas till kund. När en avvikelse upptäcks repareras verktyget genom att komponenter byts ut i en viss ordning. Genom att utöka möjligheterna till felsökning kan reparationsprocessen kortas ner. Utifrån en omfattande databas har en statistik sammanställning utförts som visar att cirka 47% av de verktyg som inte klarar sluttestet uppvisar samma felkod. Över 37% av dessa enheter repareras genom att byta verktygets huvudkort. Denna studie ger indikationer på att det i många fall inte är huvudkortet som är problemet utan felaktigheter i monteringen. Med hjälp av rotorsaksanalys, strukturerade intervjuer, enkäter och utveckling av testprotokoll samt en teststation har ett antal faktorer kunnat identifieras vilka kan bidra till en ökad processkvalitet. Undersökningen föreslår införande av en utökad testplattform som kan hjälpa reparatörerna i sitt arbete. Den föreslår även ett antal konstruktionsändringar i verktygen som omöjliggör en felaktig montering.

In this thesis, an approach for localizing culprits of degradation of quality measures in an IPTV streaming service using Bayesian net-work is presented. This task is referred to as Root Cause Analysis(RCA). The objective of this thesis is to develop a model that is able to provide useful information to technicians by generating a list of probable root causes in order to shorten the amount of time spent on trouble shooting. A performance comparison is presented in Section Experimental results with Bayesian models such as Naive Bayes (NB),Tree Augmented naive Bayes (TAN) and Hill Climbing (HC) and the non Bayesian methods K-Nearest Neighbors and Random Forest. The results of the RCA models indicated that the most frequent most prob-able cause of degradation of quality is the signal strength of the user’s Wi-Fi that is reported at the user’s TV box. / I detta examensarbete presenteras en metod för att lokalisera grundorsaken till nedgradering av kvalitet i en IPTV strömningstjänst. Denna uppgift refererar tillgrundorsaksanalys. Avsikten med denna tes är att utveckla en modell som kan tillförse tekniker med användarbar information genom att generera en lista med möjliga grundorsaker för att förkorta tiden som spenderas med felsökning. En prestandajämförelse är presenterad i Sektion Experimental results med de Bayesianska modellerna Naive Bayes (NB), Tree Augmented naive Bayes (TAN) och Hill Climbing (HC) samt de icke Bayesianska modellerna K-Nearest Neighbors och Random Forest. Resultatet av grundorsaksmodellerna indikerade att den mest frekventa mest sannolika grundorsaken till nedgradering av kvalitet är signal styrkan hos Wi-Fi nätverket vilket rapporteras i användarens TV-box.

Mobila hydrauliska ventiler används ofta i tunga industrier för att styra hydrauliska system för att hantera material. Funktionaliteten är kritisk i dessa situationer då det utgör en miljöfara och säkerhetsfara om funktionaliteten inte är uppnådd. För att säkerställa funktionaliteten kvalitetskontrollerar Nordhydraulic samtliga ventiler i en testbänk innan de skickas till kund. Läckage och manöverkraft är några av de parametrar som testas. Om en ventil inte blir godkänd omarbetas ventilen för att sedan testas om igen. Detta medför interna kvalitetsbristkostnader för Nordhydraulic. Examensarbetet syftade till att reducera ventilavvikelser vid slutprovning genom att identifiera vilka rotorsaker som bidragit till avvikelserna, utforma ett visuellt sätt att övervaka ventilavvikelserna samt att ge rekommendationer till förbättringsåtgärder för att reducera dessa. Examensarbete genomfördes med hjälp av Andersen och Fagerhaugs (2014) föreslagna metod för rotorsaksanalys. Resultatet av examensarbetet visade att slidtillverkningsprocessen, bristfällig dokumentation av data och arbetsinstruktioner var rotorsaker som har bidragit till ventilavvikelserna vid slutprovning. Enligt operatörerna var slidbyte den mest frekventa åtgärden när en ventil inte blir godkänd. Sliderna kvalitetskontrolleras under tillverkningen, men dokumenteras inte. Variationen i slidernas tillverkningsprocess kan därför inte kvantifieras eller uppskattas på ett tillfredsställande sätt, vilket innebar att det var svårt att bedöma huruvida sliderna tillverkas inom de uppsatta toleranserna. Resultatet visade även på utmaningar med dokumentationen av provdatan i enlighet med de specificerade instruktionerna. Detta betonar vikten av förstärkta dokumentationsrutiner för att säkerställa fullständighet i provdatabasen och därigenom förbättra övervakningen av ventiltesterna. Nordhydraulic rekommenderas att utöka sin statistiska processtyrning för slidtillverkningen med hjälp av ett ramverk som examensarbetet har tagit fram. Genom att definiera huruvida slidtillverkningsprocessen är stabil och duglig kan förbättringsarbeten utföras. Examensarbetet har också utformat en dashboard som Nordhydraulic kan använda för att övervaka slutprovningen visuellt och upptäcka anomalier vid slutprovningen. Sammanfattningsvis fokuserar examensarbetet på att reducera avvikelserna hos ventiler vid slutprovning för Nordhydraulic. De identifierade rotorsakerna, tillsammans med det föreslagna ramverket och den visuella övervakningsmetoden, ger värdefulla insikter för Nordhydraulic att förbättra sina kvalitetskontrollprocesser, minimera avvikelser och säkerställa högkvalitativa ventiler till sina kunder. / Mobile hydraulic valves are frequently used in heavy industries for material handling, thanks to their high power-to-weight ratio. Functionality is critical in these scenarios as it poses both environmental and safety hazards if not achieved. To ensure functionality, Nordhydraulic performs quality inspections on all valves before they are shipped to customers, utilizing a test bench. Parameters such as leakage and actuation force are among those tested. If a valve fails to meet the requirements, it undergoes rework and is retested, resulting in internal failure costs for Nordhydraulic.  The objective of this thesis was to reduce valve deviations during final testing by identifying the root causes contributing to these deviations, designing a visual monitoring approach for valve deviations, and providing recommendations for improvement measures to reduce valve deviations. This thesis utilized the root cause analysis method proposed by Andersen and Fagerhaug (2014). The results of the thesis revealed that the spool manufacturing process, insufficient data documentation, and work instructions were identified as root causes contributing to valve deviations during final testing. According to the operators, replacing the spool was the most frequent corrective action when a valve failed to meet the requirements. The variation in the spool manufacturing process could not be quantified or estimated satisfactorily, making it difficult to assess whether the components were manufactured within the specified tolerances.  The results also indicated challenges with the documentation of test data in accordance with the specified instructions. This emphasizes the importance of strengthened documentation procedures to ensure completeness in the test database and thereby enhance the monitoring of valve tests. Nordhydraulic is recommended to increase their statistical process control using the framework developed in this thesis. By defining the stability and capability of the spool manufacturing process to produce within the specified tolerances, improvement efforts can be undertaken. The thesis has also designed a dashboard that Nordhydraulic can utilize to visually monitor the final testing process and detect anomalies. In conclusion, this thesis addresses the issue of reducing valve deviations during final testing for Nordhydraulic. The identified root causes, along with the proposed framework and visual monitoring approach, provide valuable insights for Nordhydraulic to enhance their quality control processes, minimize deviations, and ensure high-quality valves for their customers.

Food loss and waste (FLW) occurring early in the food supply chain (FSC) leads to increased resource wastage, including land, water, fertilisers, pesticides, fuel, packaging, energy, and labour. Targeting FLW prevention benefits various aspects such as food security, productivity, economic growth, climate change mitigation, resource conservation, and food waste management. Understanding the causes of FLW and their environmental impact is crucial for the design of effective solutions and their prioritisation. The purpose of this study was to investigate the risk factors and underlying causes of FLW in leafy vegetables (LV), mainly lettuce, throughout the Brazilian FSC, spanning from harvest to retail. Additionally, the study evaluated the environmental impact of waste management strategies applicable in the context of the case study. To achieve this, the research methodology encompassed a case study conducted among small-scale producers and retailers in the city of Tupã, Brazil. A comprehensive approach was adopted by integrating a systematic literature review of global FLW causes and those specific to the Latin American context. This approach was complemented by exploratory research, involving interviews with various stakeholders along the FSC, coupled with rigorous root-cause analysis. Moreover, the study employed a Life Cycle Assessment (LCA) methodology to offer an immersive perspective, determining the environmental implications associated with different approaches to treating lettuce waste in the case study. Findings revealed that the root causes of FLW in the case study encompassed normalised unfair trading practices, notably take-back agreement (TBA) conditions, and the absence of supportive policies and incentives for FLW reduction. These root causes manifested in the absence of formal agreements between retailers and local producers, leading to the return of unsold or substandard items without compensation. Furthermore, supermarkets exert power over product quality but evade responsibility for proper storage or encouraging the utilisation of unsold products. Another category of significant causes, designated by the author as "major causes," encompassed causes such as unpreparedness for adverse weather conditions, lack of skilled labour, and stringent visual quality standards. These factors were pivotal risk contributors that potentially motivate various other causes of FLW. To tackle root and major causes of FLW of LV, this study proposed specific measures encompassing fair trade agreements, policy enhancements, protective measures for producers, skill development, and flexible standards. Moreover, by implementing an attributional LCA methodology, the study underscored the importance of source reduction in preventing the environmental impact of food waste for the specific context of the case study. According to the results obtained, for each kg of lettuce that is not produced, 0.065 kg CO2eq are avoided. These findings also highlighted the environmental efficacy of animal feed production, which is a cost-efficient strategy, widely prevalent in the city studied, presents a carbon footprint of -0.013 kg CO2eq/kg of waste. Other common solutions implemented at the case study, such as anaerobic digestion and composting exhibit less favourable carbon footprints, measuring 0.019 and 0.006 kg CO2eq/kg of lettuce, respectively. Landfilling emerges, as expected, as the least desirable option with a considerably higher carbon footprint of 0.423 kg CO2eq/kg. To summarise, this study highlights the environmental advantages of prioritising prevention and higher waste hierarchy levels. It underscores the need for context-specific evaluations when dealing with the intricacies of waste management systems. Moreover, the research emphasises the potential for innovative strategies, multi-stakeholder collaboration, and a holistic approach to address the complex issue of FLW, considering both the environmental impact and practical challenges in a real-world implementation.

Apesar da existência de diversos estudos que validem o uso de implantes de diâmetro estreito, a maioria é baseada em ligas de titânio puro. Há pouca evidência clínica em relação ao sucesso do implantes de diâmetro estreito de titânio-zircônia (TiZr NDIs), no que diz respeito à taxa de sobrevida (SR) e perda óssea marginal (MLB). O objetivo desta revisão sistemática foi analisar sistematicamente SR, assim como MBL de TiZr NDIs quando comparados a implantes de diâmetro estreito de titânio comercialmente puro (cpTi NDIs). A busca foi conduzida nas bases Medline/Pubmed, Cochrane, Scopus e Embase (do ano 2000 a novembro de 2016). Foram incluídos estudos clínicos do tipo coorte e randomizados. Dos 3453 artigos inicialmente identificados, foram incluídos seis estudos clínicos. Não houve diferença estatisticamente significante em taxa de sobrevida quando comparados os grupos TiZr NDIs e cpTi NDIs, em um ano de acompanhamento (p=0,5), além disso, também não houve diferença na comparação entre região de implantação (anterior ou posterior) no grupo TiZr NDIs. Não houve diferença entre os grupos anterior e posterior em relação à taxa de sobrevida em um ano: -0,01 (95% CI, -0,05 a 0,03) e perda óssea marginal: -0,01 mm (95% CI: -0,14 a 0,12). Pode-se concluir que TiZr NDIs apresentam taxas de sucesso e reabsorção óssea peri-implantar similares às de cpTi NDis. / Despite the existence of several studies validating the use of narrow diameter implants, most of them are based on pure Ti alloys. There is few clinical evidence of the success of TiZr narrow diameter implants (TiZr NDIs) regarding survival rate and marginal bone loss. The aim of this review was to systematically assess survival rate, as well as marginal bone loss of TiZr NDIs compared to commercially pure titanium narrow diameter implants (cpTi NDIs). Material and Methods: The search was conducted in Medline/PubMed, Cochrane, Scopus and Embase databases (year 2000 to November 2016). Cohort studies and randomized trials were included. Results: Six clinical studies from the 3453 articles initially identified met the inclusion criteria. There were no statistically significant differences in survival rate when TiZr NDIs and cpTi NDIs were compared in the 1-year follow up (p=0.5), or when comparing TiZr NDIs placed in posterior and anterior regions. There was no difference between groups regarding 1-year SR: -0.01 (95% CI, -0.05 to 0.03) and MLB: -0.01 mm (95% CI: -0.14 to 0.12). Conclusion: It can be concluded that TiZr NDIs present similar success rates and peri-implant bone resorption to cpTi NDIs.

The purpose of this study is to design, develop and evaluate an electronic performance support system (EPSS) for the crime scene investigation unit (CSI). For this purpose, a sequential explanatory strategy as a procedure of the mixed method design was used in analysis and evaluation of the EPSS. The research was composed of three main phases: analysis / design, development and implementation, and evaluation of the EPSS. In first phase composed of performance and cause analyses, the CSI Unit&rsquo / s existing information, and contributing causal performance factors based on Gilbert&rsquo / Behavior Engineering Model were explored. In performance analysis phase, official documentation of the CSI Unit was reviewed. As for cause analysis, the survey and focus group interviews were conducted to 1176 and 22 CSI officers, respectively. These data were analyzed using with both quantitative and qualitative methods to facilitate the selection of the most appropriate intervention and its components. Analyses results revealed that 14 basic influences grouped under the workplace and competency on human behavior impacted performance of the officers. Based on these results, an EPSS composed of intrinsic, extrinsic and external levels, and support components was designed and developed in the second phase. Having been implemented, the evaluation of the EPSS based on the Kirkpatrick&rsquo / Four Levels of Evaluation Model was conducted v to determine the overall impact, perceived benefits, and effectiveness of the intervention in third phase. In this phase, a survey, interviews, computer logs and a checklist were used so as to assess the accomplishment of the EPSS. While the survey and the checklist were administered to the 191 officers and 2 experts from the field, the interviews were conducted with 12 officers. Evaluation results admitted that the CSI officers&rsquo / reactions were very positive to the EPSS. While, an intrinsic support made a major contribution to their productivity, establishing standardization would be perceived as the major impact of the EPSS. Lastly, increasing identity and simplifying criminal justice system were the two main impact factors on the society that the system would influence positively.

Volvo Aero utvecklar, konstruerar, tillverkar och utför underhåll av motorer och tillhörande komponenter för civila och militära flygplan. Visionen är att leverera världsledande transportlösningar genom ständig förbättring och långsiktig utveckling av verksamheten, vilket för det dagliga arbetet innebär systematisk problemlösning genom metodiken praktisk problemlösning, vars ursprung är Toyota. Syftet med studien var att undersöka huruvida Volvo Aeros tillämpning av praktisk problemlösning var enkel, systematisk och vägledande, vilket ur Toyotas perspektiv ger förutsättning för effektiv problemlösning. Inledningsvis beskrevs Toyotas inställning och beteende till problemlösning utifrån The Toyota Way, som sedan följdes upp med en litteraturstudie gällande praktisk problemlösning. Vidare genomfördes en pilotstudie där Volvo Aeros tillämpning av praktisk problemlösning applicerades på ett organisatoriskt problem. Därefter utvärderades pilotstudien och förbättringsområden identifierades där metodiken var svår, otydlig och otillräckligt vägledande. Slutligen föreslogs följande förbättringar gällande Volvo Aeros tillämpning av praktisk problemlösning, vilka var vetenskapligt förankrade till Toyota. Definiering och analysering av symtomen ger förståelse för problemets orsaker. Kvantifiering av nuvarande tillstånd och det förväntades åskådliggör problemets omfattning. Framgår grundorsaken tydligt är sannolikt motåtgärden uppenbar. En god tillämpning av Plan-Do-Check-Act (PDCA) utgör ett effektivt och kraftfullt maskineri för ständig förbättring. Förbättringarna som föreslogs syftade till att förenkla Volvo Aeros metodik och ge användaren ökad trygghet och vägledning, vilket ger förutsättning för effektiv problemlösning som möjliggör daglig tillämpning och främjar ständig förbättring. / Volvo Aero develops, designs, manufactures and performs maintenance of engine and related components for civil and military aircrafts. The vision is to deliver world-leading transport solutions through continuous improvement and long term business deployment, which for the daily work means systematic problem solving through the methodology practical problem solving, whose origin is Toyota. The purpose of this thesis was to examine whether Volvo Aero’s approach of practical problem solving was simple, systematic and guided, which from Toyota’s point of view creates sound conditions for effective problem solving. Initially, Toyota’s attitude and behaviour towards problem solving was described from the point of view of The Toyota Way. Thereafter, a literature study on practical problem solving was completed. Furthermore, a pilot study was carried out where Volvo Aero’s approach to practical problem solving was applied to an organisational problem. The pilot study was evaluated and areas for improvements were identified where the methodology was difficult, indistinct and inadequate guided. Finally, improvements were proposed regarding Volvo Aero’s approach to practical problem solving, which was scientifically anchored to Toyota. Defining and analysing the symptoms brings understanding for the causes of the problem Quantifying the present condition and the expected illustrates the magnitude of the problem Appears the root cause to be clear is probably the countermeasure obvious A considerable approach using Plan-Do-Check-Act (PDCA) provides an effective and strong tool for continuous improvement The improvements were proposed with purpose to simplify Volvo Aero’s methodology and to support and guide the user, which creates sound conditions for effective problem solving and provides opportunities for daily use that foster continuous improvement.

[pt] Grandes desafios surgiram para as organizações devido ao avanço tecnológico ocorrido nos últimos tempos. Qualidade no produto não é mais um meio para se obter vantagem competitiva, mas sim uma necessidade para as organizações manterem seus clientes. Deste modo, formas para que a qualidade esteja cada vez mais presente nas organizações se fazem necessárias. Neste contexto, os objetivos do presente trabalho são estudar os principais métodos de análise de causa raiz da literatura, apresentando suas etapas, características, peculiaridades, comparação, e exemplificar a aplicação desses métodos. Uma vez conhecidos pelas organizações, a aplicação de tais métodos pode prevenir recorrência de falhas, levando às organizações a um nível superior de qualidade, aumento de produtividade, e consequentemente maior satisfação dos clientes. A pesquisa foi iniciada pelo levantamento e estudo dos métodos apontados em referências acadêmicas, Método dos 5 por quês, Diagrama de Ishikawa, Análise de Barreira de Controle, Gráfico de Fator Causal e Evento (GFCE), Análise de Árvore de Falhas (AAF) e Mapa de Causa Raiz, seguidos da apresentação de um exemplo de falha elaborado no contexto de uma indústria manufatureira metal-mecânica. Cada método foi aplicado ao problema de não conformidade. Os resultados dos métodos foram comparados e em seguida as vantagens e desvantagens dos métodos foram destacadas. Os Métodos 5 por quês, Diagrama de Ishikawa e Análise de Barreira de Controle foram considerados mais adequados para problemas considerados simples em uma organização industrial. Já para problemas considerados complexos, cujas causas raízes não são facilmente identificadas, os métodos GFCE, AAF e Mapa de Causa Raiz foram considerados os mais indicados. / [en] Great challenges emerged for organizations due to technological advance occurred in recent times. Product quality is no longer a means to gain competitive advantage, but a necessity for organizations to keep their customers. Thus, ways in which quality is increasingly present in organizations are necessary to facilitate its implementation. In this context, the objectives of this work are to study the major methods of root cause analysis of the literature, with its stages, features, peculiarities, comparison, and exemplify the application of these methods. Once known by the organizations, the application of such methods can prevent recurrence of failures, leading organizations to a higher level of quality, increased productivity, and thus increased customer satisfaction. This research was initiated by the survey and study of methods aimed at academic references, 5 Whys, Ishikawa Diagram, Control Barrier Analysis, Event and Causal Factor Charting, Fault Tree Analysis and Root Cause Map, followed by the presentation of an example fault developed in the context of a metalworking manufacturing. Each method was applied to the problem of non-compliance. The results of both methods are compared and then the advantages and disadvantages of both methods are highlighted. 5 Whys, Ishikawa Diagram and Control Barrier Analysis were considered appropriated to simple problems in an industrial organization. In complex problems cases, which root causes are not easily identified, Event and Causal Factor Charting, Fault Tree Analysis and Root Cause Map were considered more appropriated.

Denna kvalitativa fallstudie syftade till att undersöka hur riskanalysmetoden Process Failure Mode and Effect Analysis (PFMEA) tillämpas och anpassas till pappers- och massaindustrin för att proaktivt hantera processrisker. Studien baserades på antagandet att Automotive Industry Action Group (AIAG) och Verband der Automobilindustries (VDA) PFMEA-metod från år 2019 även kan användas för en process där virke omvandlas till träflis. Data samlades in genom litteraturstudier, observationer, företagsdokument, intervjuer och workshops med processexperter. Processrisker analyserades med AIAG och VDAs PFMEA-metod och tematisk analys användes för att identifiera lämpliga anpassningar av metoden. Utifrån deltagande roller och tidsåtgången för PFMEA-aktiviteter analyserades även resurser för en PFMEA. Resultatet visade att AIAG och VDAs PFMEA-metod är tillämplig för en process där virke omvandlas till träflis, förutsatt att bedömningskriterierna för allvarlighetsgrad anpassas och fiskbendiagram, 5-varför och felträdsanalys inkluderas för en strukturerad analys av grundorsaker. Totalt identifierades 36 feltillstånd, varav grundorsaksanalyser prioriterades för fyra som hade effekter med en allvarlighetsgrad åtta eller högre. För prioriterade feltillstånd identifierades elva grundorsaker för vilka åtgärder kunde rekommenderas. För att genomföra analysen under en 16-veckorsperiod uppskattades kostnaden till cirka 212 571 kr i arbetstidskostnader. Studien visar att AIAG och VDAs PFMEA-metod är en strukturerad metod för att analysera processrisker även inom pappers- och massaindustrin, om anpassningar görs av bedömningskriterier och metoder för grundorsaksanalys inkluderas. Budgeteras kvalificerad personal kan en PFMEA genomföras inom 16 veckor på en process där virke omvandlas till träflis. / This qualitative case study aimed to investigate how the Process Failure Mode and Effect Analysis (PFMEA) methodology can be applied and adapted to the pulp and paper industry for proactive management of process risks. The study assumed that the Automotive Industry Action Group (AIAG) och Verband der Automobilindustrie (VDA) PFMEA method from year 2019 could also be utilized for a process that transforms timber into wood chips. Data were collected through literature reviews, observations, company documents, interviews, and workshops with process experts. Process risks were analyzed using the AIAG and VDA PFMEA method, and thematic analysis was applied to identify suitable adaptations of the method. Resources required for a PFMEA were also analyzed based on the roles of the participants and the time for conducting PFMEA activities. The results revealed that the AIAG and VDA PFMEA method is applicable to a process that transforms timber into wood chips, provided that the severity assessment criteria are adjusted and fishbone diagrams, 5-why analysis, and fault tree analysis are included for a structured examination of root causes. A total of 36 failure modes were identified, where root cause analysis was prioritized for four failure modes exhibiting effects with a severity rating of eight or higher. Eleven root causes were identified for the prioritized failure modes for which recommended actions could be proposed. The estimated cost of labor for conducting the analysis over a 16-week period was approximately 212 571 SEK. This study demonstrates that the AIAG and VDA PFMEA method is a structured approach for analyzing process risks, even within the pulp and paper industry, if adjustments are made to the severity assessment criteria and methods for root cause analysis are included. With the allocation of sufficient resources and qualified personnel, a PFMEA can be completed within a 16-week timeframe for a process involving the conversion of timber into wood chips.

Under senare år har Stora Enso sett en stadig och ökande efterfrågan. För att möjliggöra en ökad produktion framöver, ska en investering göras vid ena kartongmaskinen på Skoghalls bruk. En ökad produktion ställer krav på att det efterföljande flödet fungerar väl och idag, upplever företaget att dagens interna logistikflöde inte alltid fungerar problemfritt. För att öka förutsättningarna för att hantera produktionsökningen, finns det därför ett intresse av att undersöka aktiviteterna i det studerade flödet och se var slöseri uppstår för att kunna reducera eller eliminera dem. Syftet med studien är därmed; Ta fram rekommenderade åtgärdsförslag för hur aktiviteterna i Skoghalls bruks internlogistik kan effektiviseras. Studien utgick ifrån tre huvudfrågor: Vilka slöserier finns det kopplat till brukslagret och Vänerterminalen och var förekommer dem?, Vilka åtgärdsförslag finns för de identifierade slöserierna? och Vilka av de identifierade åtgärdsförslagen rekommenderas för Skoghalls bruk?. Den första huvudfrågan besvarades genom att en kartläggning av nuläget gjordes med inspiration från de två första stegen av en värdeflödesanlys och ett spagettidiagram. Kartläggningen baserades på intervjuer, observationer och datainsamling som genomfördes på såväl brukslagret som Vänerterminalen. Intervjuerna genomfördes med anställda som antingen arbetade operativt eller administrativt i brukslagret och Vänerterminalen, för att få en heltäckande bild över hur aktiviteterna genomfördes och var slöserier uppstår i aktiviteterna. Utifrån informationsinsamlningen togs sju födeskartor fram som innehöll tidsmätningar för de olika aktiviteterna. Baserat på kartläggningen och sammanställningen av informationsinsamlingen identifierades slöserier kopplat till aktiviteterna. Totalt identifierades fem olika typer av slöserier vilka var: onödig transport, defekta produkter, onödig rörelse, väntan och lager. För att besvara den andra huvudfrågan genomfördes först en rotorsaksanalys, med hjälp av metoderna 5 varför och fiskbensdiagram, där rotorsakerna till slöserierna identifierades. Baserat på rotorsakerna, togs nio åtgärdsförslag fram som ämnade reducera slöserierna och därmed effektivisera aktiviteterna i det studerade systemet. Slutligen besvarades den sista huvudfrågan med hjälp av ett insats-verkan diagram där åtgärdsförslag rekommenderades utifrån förväntad effekt och insats. Baserat på förväntad effekt respektive insats definierades åtgärdsförslagen som genomförbar, möjlig, överväga och avfärda. Sammanfattningsvis beslutades fyra åtgärdsförslag som genomförbara vilka rekommenderades i första hand. Vidare beslutades tre åtgärdsförslag som möjliga vilket innebär en lägre effekt än de genomförbara och de rekommenderas därför i andra hand. Två åtgärdsförslag beslutades för att övervägas, vilka kännetecknas av både en hög insats och effekt och rekommenderas därför till att undersökas vidare för att se om insatsen kan reduceras innan åtgärdsförslaget blir aktuellt. Inget åtgärdsförslag bedömdes ha så pass låg effekt i kombination med hög insats att det bör avfärdas. I figur 1 nedan ses en sammanställning av de framtagna åtgärdsförslagen. / In recent years, Stora Enso has seen steady and increasing demand. To enable increased production in the future, an investment will be made in one of the board machines at Skoghall Mill. Increased production requires that the subsequent flow works well, and today the company has expressed that the current internal logistics flow does not always work smoothly. In order to increase the conditions for managing the increase in production, there is an interest in investigating the activities in the studied flow. This is to see where waste occur in order to reduce or eliminate them. The purpose of the study is thus; To provide recommended suggestions for how the activities in Skoghall Mill’s internal logistics can be made more efficient. The study was based on three different main questions: What wastes are there linked to the mill warehouse and V¨anerterminalen and where do they occur?, What suggestions are proposed for the identified wastes? and Which of the identified suggestions are recommended for Skoghall mill?. The first main question was answered by mapping the current situation with inspiration from the first two steps of a value stream mapping and a spaghetti diagram. The mapping was based on the interviews, observations, and data collection conducted at both the mill warehouse and V¨anerterminalen during the implementation phase. The interviews were conducted with employees who worked either operationally or administratively in the mill warehouse and V¨anerterminalen, to get a comprehensive picture of how the activities were carried out and where waste occurs in the activities. Based on the collected information, seven flow maps were produced that contained time measurements for the different activities. Based on the mapping and the collected information, wastes linked to different activities were identified. A total of five different wastes were identified which were:transportation, defects, motion, waiting and inventory. To answer the second main question, a root cause analysis was first carried out, using the 5 why and fishbone diagram methods, where the root causes of the wastes were identified. Based on the root causes, nine proposed suggestions were developed that aimed to reduce waste and thus make the activities in the studied system more efficient. Finally, the last main question was answered using an impact-effort diagram where recommended suggestions were presented based on expected impact and effort. Based on expected impact and effort the proposed suggestions were defined as feasible, possible, consider and reject. To summarise, four proposed suggestions were decided to be feasible and recommended in the first instance. In addition, three proposed suggestions were identified as possible, which means a lower impact than the feasible ones, and are therefore recommended in the second place. Two proposed suggestions were decided to be considered, and these proposed suggestions are characterised by both a high effort and impact and are therefore recommended to be investigated further to see if the effort can be reduced before the proposed suggestion becomes relevant. No proposed suggestion was judged to have such a low impact in combination with high effort that it should be dismissed. Figure 2 below shows a summary of the proposed suggestions.