The purpose of this literature study is to explore the most important ergonomic factors that play a role in shaping the work environment of assembly line systems. Since the subject of ergonomics in production systems has continuously gained great interest in the past years, it was decided to conduct research around this topic. The literature study type was chosen to answer the research questions. This was done because even though various articles discuss the mentioned areas, they usually still have a specific focus. For example, human errors, automation, simulation, virtual reality, etc. Therefore, it was decided to carry on with a more comprehensive review that takes into account the most important ergonomic factors in general and how they influence assembly workstations both positively and negatively. Thus, two research questions were explored: Research question:  What are the most important ergonomic factors that influence an assembly line system’s work environment? Sub-research question: What are the positive and negative effects and what causes them? In order to proceed with the study, a systematic literature review and thematic analysis were conducted through the use of secondary data only. This was done by searching for different articles through two academic databases; ScienceDirect and Scopus. Lastly, the words that were used to search for articles were highly relevant in terms of the research questions. In regards to the analysis and conclusion, different factors were found including automation and cobots, job rotation, the implementation of human factors, and repetitive manual tasks. The results showed that all these factors can affect an assembly line system’s work environment to a great extent, both positively and negatively. First of all, cobots contribute by helping human operators with difficult tasks, yet, the collaboration of humans and robots is viewed as risky to some extent. Furthermore, the level of the implementation of ergonomics at workplaces is crucial to provide a healthy work environment. Ultimately, repetitive tasks can have a great impact on workers, and thereby the whole work environment becomes affected. Therefore, convenient training sessions are highly important to ensure safety in such cases.

Purpose - This thesis aims to developing a decision-making tool which fits in a reconfigurable manufacturing system (RMS) milieu used to identify whether to introduce and produce a new product into an already existing assembly line or to invest in a new assembly line. To fulfil the purpose, four research questions were developed.  Which line balancing problem-solving techniques exist in the literature? Which investment costs can be considered vital for new assembly lines as a    consequence from new product introductions? Can a decision-making tool be designed to evaluate new product introductions which considers both line balancing KPIs and investment costs in an assembly line? To what extent can criteria in the RMS theory be linked with the attributes of the    designed decision-making tool to support its applicability? Method - Literature studies were performed in order to create a theoretical foundation for the thesis to stand upon, hence enabling the possibility to answer the research questions. The literature studies were structured to focus on selected topics, including reconfigurable manufacturing systems, line balancing, and assembly line investment costs. To answer the third research question, which involved creating a decision-making tool, a single-case study was carried out. The company chosen was within the automotive industry. Data was collected through interviews, document studies and a focus group. Findings & analysis - An investigation regarding which line balancing solving-techniques suit RMS and which assembly line investment costs are critical when  introducing new products has been made. The outputs from these  investigations set the foundation for developing a decision-making tool which enables fact-based decisions. To test the decision-making tool’s compatibility with reconfigurable manufacturing systems, an evaluation against established characteristics was performed. The evaluation identified two reconfigurable manufacturing system characteristic as having a direct correlation to the decision-making tool. These characteristics regarded scalability and convertibility. Conclusions - The industrial contribution of the thesis was a decision-making tool that enables fact-based decisions regarding whether to introduce a new product into an already existing assembly line or invest in a new assembly line. The academic contribution involved that the procedure for evaluating the tool was recognized as also being suitable for testing the reconfigurable correlation with other production development tools. Another contribution regards bridging the knowledge gaps of the classifications in line balancing-solving techniques and assembly line investment costs. Delimitations - One of the delimitations in the thesis involved solely focusing on developing and analysing a decision-making tool from an RMS perspective. Hence, other production systems were not in focus. Also, the thesis only covered the development of a decision-making tool for straight assembly lines, not U-shaped lines.

En verkstad som tillverkar växellådor planerade att bygga om verkstaden. Det fanns flera problem i verkstaden som indirekt påverkade produktionen. Att tåg stod stilla utan att göra ett aktivt arbete på en huvudled i verkstaden sågs som ett stort problem. Ett annat problem var att det fanns för många tåg i verkstaden. Den planerade ombyggnationen var till för att få ned antalet tåg i verkstaden. Med ombyggnationen ville verkstadens ansvariga undersöka ytterligare möjligheter hur verkstaden skulle kunna förändras och kunna lösa delar av problemen. Det var även intressant att se om möjliga implementeringar av verkstaden skulle ge en ökad produktion. Målen var att skapa ett simuleringsverktyg för att undersöka hur olika lösningar som baserades på ombyggnationen skulle kunna påverka ett tåg som fyllde på material till monteringslinor i verkstaden. För att kunna testa olika lösningar behövde en simuleringsmodell utvecklas och verifieras mot den befintliga lösningen i verkstaden. Därefter utökades modellen för att testa nya lösningar. Från verkstaden fanns det data på konsumering av material. För tåget som skulle fylla på material fanns det teoretiska tider för olika arbetsmoment. Konsumeringen av material uppförde sig enligt en slumpfördelning som var normalfördelad. Resultatet blev att endast konsumeringen av material kunde verifieras då det bara fanns data på hur konsumtionen av material skedde. Resterande delar av simuleringen använde teoretiska planerade värden. Av de undersökta lösningarna var det en lösning med en ny hållplats på en mindre trafikerad väg, där ett tåg kunde vänta, som visade ett mer önskat resultat än de andra som undersöktes. / A workshop that produces gearboxes planned to remodel the workshop. There were several problems that indirectly affected the production. The fact that trains stood still without doing active work on the main road in the workshop was a major problem. Another problem was that there were too many trains in the workshop. The planned reconstruction was to reduce the number of trains in the workshop. With the remodel, those responsible for the workshop wanted to explore further possibilities on how the workshop could be changed. It was also interesting to see if the implementation of changes would give an increased production. The goals were to create a simulation tool to investigate how different solutions based on the rebuild could affect a train that loaded the material into assembly lines in the workshop. To be able to test different solutions, a simulation model needed to be developed and verified against the existing solution. Then the model was expanded to test new solutions. From the workshop there was data on the consumption of materials. For the train that would load up on materials, there were theoretical times for various work tasks. The consumption of materials behaved according to a random distribution that was normally distributed. The result was that only the consumption of materials could be verified as there was only data on how the consumption of materials took place. Remaining parts of the simulation used theoretically planned values. Of the solutions investigated, it was a solution with a new bus stop on a less busy road, where a train could wait, that showed a more desirable result than the others that were investigated.

The Swedish heavy vehicle manufacturer Scania is currently phasing out their main engine assembly line in favor of a new assembly line. As a consequence, there is a need to adjust the logistics to the phase-out to maintain efficiency and free up space. Due to a lack of literature on this particular subject, it has been noticed that both Scania and the literature could benefit from a theoretical methodology that provides general guidance on how to approach reductions in production volume from a logistics perspective. To explore this problem the study answers the research question ”How can heavy vehicle manufacturing companies optimize inventory space at an assembly line when the production volume decreases?”. The study focused on a smaller internal logistics area within Scania’s Södertälje assembly plant, to develop a theoretical methodology that is also applicable to other areas and companies facing similar challenges. The phase-out will be executed in stages, starting with the most common engine types. The production volume will be reduced by changing the takt and removing engine carriers. Takt is a term used to describe the time that an engine spends at each assembly line station. The reduction in production volume leads to a proportional reduction in the amount of material picked at the logistics platforms. Consequently, the material stays in stock for a longer time, and the efficiency of the material handlers decreases. To maintain the stocking times and efficiency of the material handler, the study found that packaging sizes should be reduced in proportion to the production volume, as this would enable the storage to hold fewer items of each article while also holding a larger variety of articles previously stored elsewhere. As a result, additional activities can be given to the material handlers, while also freeing up inventory space that can be used to introduce the new assembly line. Approaching these challenges can be done following the theoretical methodology that has been developed in this study, consisting of three steps: Overview of Potential Changes, Quantifying Inventory Changes, and Calculating Inventory Space. Guided by this theoretical methodology, the study identified that the main potential changes revolved around packaging sizes. Changes in packages were then quantified for the 220 articles stored in the logistics area and synchronized with the phase-out to maintain the current stocking times. At the first step of the phase-out, when the takt is reduced to 3/4-takt, 107 packages could be changed, resulting in a 34% reduction in inventory space, indicating that one of the three logistics platforms in the logistics area can be closed. In the following stages of the phase-out, the further reduction in inventory space is marginal resulting in a final reduction of 46% at 1/3-takt, which might suggest that other approaches are more beneficial later on. As a result of this study, companies facing challenges adjusting the logistics to reduced production volumes can find guidance in the theoretical methodology presented in this thesis. The theoretical methodology highlights important aspects to consider based on both literature and empirical findings from the case study so that the efficiency of the logistics can be maintained during assembly line phase-out / Den svenska lastbilstillverkaren Scania håller för närvarande på att fasa ut en av deras primära monteringslinor för att ersätta denna med en ny. En konsekvens av detta är att den interna logistiken måste anpassas för att behålla dess effektivitet och frigöra lageryta. I dagsläget är litteraturen inom detta ämne begränsad, vilket innebär att både Scania och litteraturen som helhet gynnas av en teoretisk metodik som generellt beskriver hur intern logistik kan anpassas vid varierande produktionsvolymer. För att undersöka detta besvarar denna studie forskningsfrågan ”Hur kan tunga fordonstillverkare optimera lageryta vid monteringslinor vid minskad produktionsvolym?”. Studien fokuserar på ett mindre internt logistikområde vid Scanias motormonteringsanläggning i Södertälje. Målet är att inom detta område presentera en teoretisk metod som är applicerbar på samtliga logistikområden på Scania, såväl som hos andra företag med liknande utmaningar. Scania planerar att genomföra utfasningen stegvis, där det första steget innebär att de vanligaste motortyperna fasas ut och övergår till den nya monteringslinan. Produktionsvolymen kommer att minskas genom taktminskning, samt genom att plocka bort ”carriers” (stativen som motorerna monteras på). Takt är en term som beskriver den tid varje enskild motor befinner sig vid varje monteringsstation. Den minskade produktionsvolymen innebär en proportionell minskning i åtgång av komponenter och produktionsmaterial. Till följd av detta ökar lagertiden och effektiviteten för materialhanterarna minskar. För att bibehålla lagertiden och effektiviteten visade studien att förpackningsstorlekarna borde minskas, vilket innebär att färre artiklar lagerhålls, samt att fler varianter av artiklar kan lagras på mindre yta. Vidare kan materialhanterarna tilldelas fler arbetsuppgifter och den frigjorda yta utnyttjas av den nya monteringslinan. Dessa utmaningar kan hanteras enligt följande metodik med tre steg: 1. Överblick över möjliga ändringar, 2. Kvantifiera möjliga lagerbesparingar och 3. Beräkna lagerbesparingar. Baserat på denna metodik, fann studien att den största potentialen fanns genom ändrade förpackningsstorlekar. Förpackningsändringarna kvantifierades för de 220 artiklarna inom det behandlade området, med hänsyn till taktreduceringen och bibehållen lagertid. Vid första nedrampningssteget när takten reducerats till 3/4, visade studien att 107 förpackningsändringar kunde genomföras, vilket resulterade i en reducering av lageryta på 34%. I praktiken innefattade denna minskning i krävd lageryta att en av tre logistikplattformar inom logistikområdet kan stängas ned. Vid efterföljande nedrampningssteg var lagerbesparingarna marginella med en slutlig reduktion på 46% vid 1/3-takt, vilket implicerar att andra aspekter borde beaktas senare under nedrampningsprocessen.  Avslutningsvis poängterar studien att företag med liknande utmaningar gällande logistik och reducerade produktionsvolymer kan finna vägledning med hjälp av den teoretiska metod som presenterats i denna studie. Denna metod belyser viktiga aspekter som måste beaktas, baserat på litteratur så väl som empiriska resultat från fallstudien. Detta med fokus på att bibehålla effektiviteten och minimera lageryta vid nedrampning av monteringslinor.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-04-01T15:36:14Z No. of bitstreams: 1 Rafael Pieretti de Oliveira.pdf: 3388474 bytes, checksum: e72d643abe55c81d631b660ecefa28c4 (MD5) / Made available in DSpace on 2015-04-01T15:36:14Z (GMT). No. of bitstreams: 1 Rafael Pieretti de Oliveira.pdf: 3388474 bytes, checksum: e72d643abe55c81d631b660ecefa28c4 (MD5) Previous issue date: 2013-02-28 / Nenhuma / Esta dissertação apresenta uma proposta de método para dimensionamento e gestão de linhas de montagem em boxes operadas por equipes. O método é proposto visando abordar e integrar o Sistema Toyota de Produção (STP) e a Teoria das Restrições (TOC). Esta pesquisa utiliza como base metodológica o Design Research, onde encontra-se estruturado em cinco fases: i) conscientização do problema; ii) sugestão; iii) desenvolvimento do artefato; iv) avaliação; e v) conclusão. O método sugerido para dimensionamento e gestão de linhas de montagem operadas por equipes consiste em 22 etapas: duas etapas preliminares: montagem da equipe de implementação e treinamento da equipe de implementação; duas etapas de Demanda: o que a linha vai produzir e qual a demanda a ser atendida, calculo do takt time; cinco etapas de Oferta: qual o fluxo atual dos produtos na linha, detalhamento das operações, quantas pessoas farão parte da linha, definição dos boxes de trabalho, e divisão das atividades/trabalho nos boxes; uma de comparação do takt time x tempo de ciclo: a linha terá condições de atender a demanda prevista (Takt > TC); definição da estratégia de melhoria do gargalo; estratégia para redução dos custos de produção da linha; qual a documentação do projeto; definição dos indicadores de desempenho da linha; método de trabalho na linha; operacionalização da linha de montagem; e gerar ações para solucionar problemas. O desenvolvimento e avaliação do artefato foram realizados em uma empresa fabricante de carretas localizada na cidade de Caxias do Sul. / This thesis presents a proposal for a method to dimension and manage assembly lines in boxes operated by teams. The method aims to approach and integrate Toyota Production System (TPS) and Theory of Constraints (TOC). This research uses Design Research as methodological basis, and is structured in five phases: i) problem awareness ; ii) proposal, iii) artifact development; iv) evaluation; and v) conclusion. The method proposed to dimension and management of assembly lines operated by teams consists of 22 steps: two preliminary steps: implementation team structure and training; two steps of demand: what the line will produce and what demand will be met, takt time calculation; five steps of supply: what the current flow is of the products on the line, operations detailing, how many people will be part on the line, boxes definition and activities in the boxes; one step of takt time x cycle time comparison: if the line meets the previewed demand (Takt> TC); bottleneck strategy definition; cost production strategy of the product; what the project documentation is; indicators definition; work method on the line; assembly line operationalization; and actions to solve problems. The development and evaluation of the artifact were done in a company that assemblies road implements in the city of Caxias do Sul.

Orientador: Antonio Batocchio / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-11T07:20:48Z (GMT). No. of bitstreams: 1 Fagundes_RenatoAlexandre_M.pdf: 1173048 bytes, checksum: f9c42d8865a1d2718c308d673b82bd20 (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem como objetivo a implementação de um processo cadenciador (ou puxador) na linha de produção de uma indústria fabricante de placas de circuito impresso rígidas, focando principalmente na implantação de um sistema cadenciador para que o fluxo de produção flua de uma maneira cadenciada e limpa para atender uma determinada família de produtos de placas de circuito impresso rígido (não metalizadas ¿simples face¿ e metalizadas ¿dupla face¿). A montagem da célula de produção para o estudo foi desenvolvida a partir da análise da técnica de mapeamento de fluxo estendido para se obter a melhor produtividade do sistema e atender as demandas do cliente final. A existência de algumas formas de variabilidades nos tempos takt, balanceamento de operadores, tempo para troca de modelos e dimensionamento do ciclo de máquinas foram estudadas e apresentadas buscando sempre uma otimização do fluxo contínuo dentro do processo cadenciador. Através das técnicas de mapeamento de fluxo de valor foi montado um mapa de estado atual e futuro o qual nos permite visualizar de uma maneira mais clara as correções propostas. Palavras chaves: Manufatura enxuta, Mapeamento de Fluxo de Valor, Tempo Takt, OBC / Abstract: This work has as objective the implementation of a pacemaker process in the line of production of an industry manufacturer of rigid printed circuit board, where the major is on the implantation of a pacemaker process allowing a production flow clean and smoth for one definitive product family of the printed circuit board (not metallized "single face" and metallized "double face"). The assembly of the cell of production for the study was developed from the analysis of the technique of Mapping Stream Value to get the best productivity of the system and to take care of the demands of the final customer. The existence of some forms of variabilities like : takt time, balancing of operators, time for exchange of models and sizing of the cycle of machines had been studied and presented searching always an optimization of the continuous flow inside of the pacemaker process. Through the techniques of Mapping Stream Value from the current state to future state was mounted which in allows them to visualize in a clear way of the corrections proposals. Key words- Lean Manufacturing, Value Stream Mapping, Takt Time, OBC / Mestrado / Planejamento e Gestão Estrategica da Manufatura / Mestre em Engenharia Mecânica