The current project addresses the productivity improvement of a manual assembly line by making use of operations analysis in the framework of Lean production. A methodology is proposed that helps to improve the productivity of any production process. The methodology consists of selecting a product or product family to be studied followed by current process study. Once the existing process is documented, all the assembly tasks involved must be timed using time study techniques. Operations analysis enables the reduction of non-productive tasks and results in a set of standardized work elements along with the set of standard procedures for performing the operations. Assembly line balancing along with the associated operations analysis assists in constructing or re-configuring an assembly system, which is the key step in improving the overall performance of an assembly line. Following this approach, two manual assembly line configurations (single stage parallel line and five-stage serial line) are constructed for a case study. The results show that by changing over to the single stage assembly line configuration the operator productivity is doubled when compared to the existing assembly method.

Information is an important part of the manual assembly process. Information provides the user with the means to fulfil assembly tasks so that the right quality as well as high productivity are accomplished. This thesis addresses issues connected to information and information use in a modern manual assembly environment, and how these issues affect human operators, quality and productivity. The overall objectives of the research were to gain further knowledge on how attention affects the internal reject rate, to investigate these phenomena in industrial and laboratory environments and finally to propose a suitable evaluation method to be utilised at the design stage of an information system. Studies were performed with the purpose of investigating how the assembly personnel were affected by the information and how it affected quality and productivity. The studies were performed in an assembly plant and in the laboratory. Quantitative data collection included 10 days and nights of production where the information impact on quality was investigated. Connected to this study was a qualitative survey performed among 171 persons from the assembly personnel. The laboratory study took place during three days, approximately eight hours each day. It involved 30 persons, all experienced assembly workers from the reference assembly plant. The focus of this study was how information affected the personnel and thereby the productivity. The findings revealed that information affected the quality rates and productivity and that this can be linked to how the information is presented as well as when the information is presented. It was possible to link these findings to the outcome of a successful information search process, and to conclude that a use of an evaluation method or work process during the product lifecycle could have made it possible to avoid some of the problems connected to the information presentation. This is the basis for a proposed pragmatic evaluation method. The method was tested as a support system during the design of a prototype user interface to be used at the pilot plant. The major contribution of this research is the connection between attention and quality as well as the connection between attention and productivity. Knowledge regarding the importance of presenting the information at the right time must also be regarded as an important and proven contribution.

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Tillverkningsindustrin förändras och ny teknik utvecklas ständigt. Med ny teknik så uppstår nya utmaningar. En vanlig utmaning som många industrier står inför är standardiseringen av processer. För att förbättra produktiviteten krävs standardisering. En del manuella aktiviteter kan inte standardiseras. Dessa aktiviteter är det främsta hindret för automatisering inom tillverkningen. Dessa aktiviteter har då definerats med begreppet “Hard to determine”. Detta begrepp har tagits fram från time data management principen “time determination”, vilket är ett steg inom metoden. Steget går då ut på att utföra tids datainsamling för att sedan bestämma hur långt tid ett monteringsmoment tar. Detta arbete har utförts på uppdrag av Youngkuk Jeong, som är en assisterande professor på Kungliga Tekniska Högskolan. Med detta i åtanke så har följande tre forskningsfrågor ställts och besvarats i detta arbete. ● Vad definierar en hard to determine aktivitet?● Vad kan användas för att samla tids data kring hard to determine aktiviteter?● Är det möjligt att utföra en automatisk tids data insamling på hard to measure aktiviteter? För att besvara frågorna har ett flertal studiebesök gjorts hos ett företag som vill lösa sina problem med “Hard to determine” (HTD) aktiviteter i sina manuella monteringslinjer. Förutom studiebesök har intervjuer genomförts med relevanta ingenjörer och medarbetare med ansvar för tidsdatahantering. Rapporten innehåller också en fallstudie med ett monteringsmoment som liknar den hos företaget. Ett experiment har även utförts för att testa om automatiskt tids data insamling av fallstudien är möjligt. Resultatet ger då en definition av HTD aktiviteter: ● När en viss uppgift varierar i tiden den tar att slutföra.● Hantering av oförutsägbara material.● Användning av flera typer av material baserat på kundorder.● Aktiviteten är svår att standardisera. Dessa indikatorer bidrar till att göra en uppgift HTD, och kan även användas som en kriterielista när man identifierar dessa aktiviteter. För närvarande mäter företaget alla sina aktiviteter med ett tidtagarur inklusive HTD-aktiviteter. Det finns dock möjlighet till att att använda olika typer av sensorer. Experimentet ämnar att jämföra resultaten från en manuellt insamlad tidsdata från ett stoppur mot en automatiskt insamlad tidsdata från en kamera med hjälp av en spårningsprogramvara. Resultatet tyder på att automatisk tidsdatainsamling med hjälp av kameror är ett användbart alternativ för företag som söker innovativa automationslösningar för HTD aktiviteter. / The manufacturing industry is changing and new technology is constantly evolving. With new technology, new challenges occur. One common challenge many industries face is the standardisation of processes. To improve productivity standardisation is required. However some manual activities cannot be standardised. They are the main barrier to automation in manufacturing. These activities have been defined with the term “Hard to determine”. This concept has been developed from the time data management principle “time determination”, which is a step within the method. The step involves performing time data collection, to then determine how long an assembly task takes. This research has been carried out on behalf of Youngkuk Jeong, who is an assistant professor at the Royal Institute of Technology. With this in mind, the following three research questions have been asked and answered: ● What defines a hard to determine activity?● What can be used to gather time data on hard to determine activities?● Is it possible to perform automatic time data gathering on a hard to determine activity? Several study visits have been made to a company that wants to solve its problems with "hard to determine" (HTD) activities in its manual assembly lines. In addition to study visits, interviews were conducted with relevant engineers and employees responsible for time data management. The report also includes an experimental case study with an assembly task similar to that of the visited company. An experiment has also been performed to test whether automatic time data gathering of the case study is possible. The result detail a definition of HTD activities: ● When a certain task varies in time it takes to complete.● Handling unpredictable materials.● Use of several types of materials based on customer orders.● The activity is difficult to standardise. These indicators help to determine if a task is HTD, and can also be used as a list of criteria when identifying these activities. Currently, the company measures all its activities with a stopwatch, including HTD activities. The experiment aims to compare the results of a manually collected time data from a stopwatch with an automatically collected time data from a camera using a tracking software. The results indicate that automatic time data collection using cameras and hand tracking software is a useful alternative for companies looking for innovative automation solutions for HTD activities.

En ökad trend mot mer kundspecifika produkter har ökat antalet produktvariationer. I och med denna ökning ställs högre krav på montörer som utför manuell montering vilket bidrar till en högre kognitiv belastning på montörerna. Vid manuell montering innefattar varje specifikt fall olika förutsättningar vilket innebär att kraven på montören i fråga varierar utifrån given situation. Om montören upplever tidspress i sådana situationer kan det resultera i ökad mental belastning vilket i sin tur kan öka risken för skador och sjukdomar samt lägre produktivitet för monteringsprocessen. Därav anses montörens välmående vara en viktig aspekt gällande hållbarhet vid manuell montering. I och med detta behöver kritiska faktorer som påverkar montörernas välmående tas i beaktning vid planering av monteringsprocesser. Syftet med denna studie är att utreda hur planeringsarbetet för manuella monteringsprocesser påverkar välmåendet för montörer på företag som tillämpar enstycksproduktion i den svenska tillverkningsindustrin. Detta uppnåddes genom att identifiera befintliga metoder och verktyg gällande tidsestimering samt samla data kring hur ett företags anställda upplever arbetsmiljön och planeringsarbetet för den manuella monteringsprocessen. Denna information möjliggjorde sedan utformning av en förbättrad lösning i form av en tidsestimeringsmodell som tar social hållbarhet i beaktning. Studien har en kvalitativ forskningsdesign där en fallstudie har genomförts på det svenska företaget FlexQube. Insamlingen av data gjordes genom semistrukturerade intervjuer samt analys av dokument som erhölls från det studerade företaget. Resultatet påvisar att montörers välmående påverkas av faktorer såsom ljudvolym, monteringsprocessens ergonomi, tidspress, stämning i produktionen, variation av arbetsuppgifter samt mängden information montörerna erhåller. Genom att efterfölja studiens föreslagna rekommendationer, som tar dessa faktorer i beaktning, vid planering av monteringsprocesser samt implementera studiens framtagna tidsestimeringsmodell kan företags manuella montering bli mer hållbar. / An increased trend towards more customer specific products has led to an increased amount of product variants. This increase results in higher demands on the assembler who performs the manual assembly, which in turn leads to a higher cognitive load of the assembler. Every case in manual assembly includes different conditions which leads to varied demands for the assembler depending on the situation. If the assembler experiences time pressure in such situations, it can result in increased mental pressure. This can in turn increase the risk for injuries and illnesses as well as reduced productivity for the assembly process. Therefore, the wellbeing of the assembler is considered an important aspect regarding sustainability in manual assembly. Due to this, critical factors which affect the wellbeing of assemblers should be taken into consideration when planning the assembly process.  The purpose of this study is to investigate how the planning work for manual assembly processes affects the wellbeing of assemblers at companies that apply one-piece production in the Swedish manufacturing industry. This was achieved by identifying existing methods and tools for time estimation, and by collecting data regarding how the employees at a company experience their work environment and planning work for the manual assembly. This information then led to the production of a time estimation model. The study has a qualitative research design where a case study was performed at the Swedish company FlexQube. The data was collected through semi structured interviews and by analysis of documents that were provided by the studied company. According to the results, the wellbeing of assemblers is affected by factors such as volume, ergonomics of the assembly process, time pressure, the atmosphere in the production area, the variety of work tasks, and the amount of information that the assemblers are provided. By following the study’s proposed recommendations, which considers these factors, when planning the assembly process and by implementing the produced time estimation model, the manual assembly for companies can become more sustainable.

Increasing demands, a need for more efficient manufacturing processes and pressure to remain competitive have been driving the development and use of technology in the industry since the industrial revolution. The number of operational industrial robots worldwide have been increasing every year and is expected to reach 3 billion by 2020. The aerospace industry still faces difficulty when it comes to automation due to the complexity of the products and low production volumes. These aspects make the use of traditional fixed robots very difficult to implement and economically unfeasible, which is the reason why the assembly process of aircrafts is mainly a manual work. These challenges have led the industry to consider other possibilities of automation, bringing the attention of many companies to humanoid robots. The aim of this thesis was to investigate the applicability of autonomous humanoid robots in aircraft assembly activities by focusing on four domains: mobility, manipulation, instruction supply and human-robot interaction. A case study was made in one workstation of the pre-assembly process of a military aircraft at Saab AB, in order to collect technical requirements for a humanoid robot to perform in this station. Also, a state-of-the-art literature review was made focusing on commercially available products and ongoing research projects. The crossing of information gathered by the case study and the state-of-the-art review, provided an idea of how close humanoid robots are to performing in the aircraft assembly process in each of the four domains. In general, the findings show that the mechanical structure and other hardware are not the biggest challenge when it comes to creating highly autonomous humanoid robots. Physically, such robots already exist, but they mostly lack autonomy and intelligence. In conclusion, the main challenges concern the degree of intelligence for autonomous operation, including the capability to reason, learn from experience, make decisions and act on its own, as well as the integration of all the different technologies into one single platform. In many domains, sub-problems have been addressed individually, but full solutions for, for example, autonomous indoor navigation and object manipulation, are still under development.

Modern manufacturing systems seem to be shifting from mass production to mass customisation, which means that systems must be able to manage changes in customer demands and requirements, new technology as well as environmental demands. This in turn leads to an increase in product variants that need to be assembled. To handle this issue, well designed and presented information is vital for assembly workers to perform effective and accurate assembly tasks. In this thesis the main focus has been to find factors that affect human performance in manual assembly. A literature review was made on the subject of manufacturing and usability as well as basic cognitive abilities used to utilise information, such as memory. This investigation identified applicable factors for assessing human cognitive performance within the research field of manufacturing. The thesis further investigates how some of these factors are handled in manual assembly, using case studies as well as observational studies. The results show that how material and information are presented to the assembler needs to be considered in order to have a positive effect on the assembly operation. In addition, a full factorial experimental study was conducted to investigate different ways of presenting material and information at the workstation while using mixed assembly mode with product variants. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit and the information presentation factor involved using a text and number instruction compared to a photograph instruction. The results showed that using a kit is favourable compared to the traditional material rack, especially when using a structured kit combined with photographic instruction. Furthermore, the use of unstructured kits can lead to better productivity and reduced perceived workload, compared to a material rack. Although they are perhaps not as good as using a structured kit, they most likely bring a lower cost, such as man-hour consumption and space requirements. However, the number of components in an unstructured kit needs to be considered in order to keep it on a manageable level. As a conclusion, several scenarios were developed in order to understand how different assembly settings can be used in order to improve human performance at the assembly workstation.

Manual assembly workers have nowadays a much higher workload than before. Not only do they have to deal with many more product variants, but as aconsequence they also receive many more information signals that they have to act upon. This study focuses on the information assembly workers receive through visual instructions. By conducting a literature review in the domains of product development with focus on design for assembly, cognition related to informationin instructions and different instruction formats like paper, tablet, and augmented reality (AR), commonalities and differences could be identified. Assembly operations are generally divided in handling a part and joining a part, and instructions should inform the assembly worker about when what should be assembled where and how. Each of these aspects has an impact on the overall complexity of the assembly process. To realise which of these aspects is most critical for an assembly worker can be of help in creating and delivering effective, tailor made instructions. The main finding is that there is not a one size fits all solution when it comes to the effectiveness of instructions, but that the type of instructions and the way they are delivered should in the first place be adjusted to the complexity of the assembly operations and secondly - if possible - also adjusted to the experience of the worker. The outcomes mentioned in this document should help laying the foundation for rules and guidelines when it comes to manual assembly instructions and its factors to consider.

This is a bachelor thesis which handles a balancing problem in a manual assembly line for mixed models. Many product variations that are assembled in an assembly line have different cycle times in each operation in the process. The products that are assembled in the line have also large variations in their lead times. This leads to large balancing losses leading to reduced productivity and efficiency. Many balancing losses occur due to the inefficient time that one of the products causes. Other balancing losses occur due to bottlenecks that occur in some operations. The purpose of this study is to investigate the balancing losses in a manual assembly line with mixed models. The goal is to develop a proposal for a balanced layout, as well as to minimize balancing losses and waste and maximize productivity as much as possible. Two research questions have been developed as guidelines for the study: RQ1: What factors can lead to balancing losses in a mixed-model assembly line? RQ2: How can a mixed-model assembly line be balanced without leading to other types of losses? The study is a case study that looks for problems in one case company. It is based on a literature study and the collection of real-world data, which has been collected at the case company by observations, interviews and documents that include data about production times and balancing reports.  A proposal on how balancing losses can be reduced in the best possible way has been developed. The inefficient time has been reduced and the assembly line has become more efficient and productive. With help of this improvement proposal, other types of losses could be avoided, such as losses of human resources and financial resources. This study aimed to reduce the balancing losses that one product causes in the assembly line. No rebalancing of the other products was done, but other products were considered so that the balancing of the product does not lead to extra imbalance on the other products in the line. It was important for the fall company to be able to implement a solution that does not lead to a lot of other losses. Based on the three solutions proposed, this solution was the most suitable for what the company wants. A new layout for the product’s stations has been proposed. With this layout, efficiency will increase, and downtime will decrease, thus increasing productivity. Proposal three shows that it is possible to balance a mixed-model assembly line, by terminating a product and removing it earlier from the assembly line.   Keywords: Line balancing, manual assembly, balancing loss, mixed products, mixed-model assembly / Det här är ett examensarbete på grundnivå, som behandlar ett balanseringsproblem i en manuell monteringslinje för mixade modeller. Det monteras många produktkonfigurationer som har olika cykeltider i varje station i processen. Produkterna som monteras i linan har även stora variationer i deras ledtider. Detta medför stora balanseringsförluster som leder till minskad produktivitet och effektivitet. Många balanseringsförluster uppstår på grund av den ineffektiva tiden som en av produkterna orsakar. Andra balanseringsförluster uppstår på grund av flaskhalsar som förekommer i vissa stationer.  Syftet med denna studie är att undersöka balansringsförlusterna i en manuell monteringslinje med mixade modeller. Målet är att ta fram ett förslag på en balanserad layout, samt att minimera balanseringsförlusterna och slöseri och maximera produktiviteten så mycket som möjligt.   Två forskningsfrågor har tagits fram som riktlinjer för studien: F1: Vilka faktorer kan leda till balanseringsförluster i en mixad-modellmonteringslinje?  F2: Hur kan en mixad-modellmonteringslina balanseras utan att leda till andra typer av förluster? Studien är en fallstudie som undersöker problem hos ett fallföretag. Studien är baserad på en initial litteraturstudie och insamlad data, som har samlats in från fallföretaget via observationer, intervjuer samt dokument med data om produktionstider och balansrapporter.  Ett förslag på hur balanseringsförlusterna kan minskas på bästa möjliga sätt har tagits fram. Den ineffektiva tiden har minskats och monteringslinan har blivit effektivare och produktivare. Med hjälp av det här förbättringsförslaget, kunde andra typer av förluster undvikas, som exempelvis förluster av mänskliga resurser och ekonomiska resurser.   Denna studie är gjord för att minska balanseringsförlusterna som en av produkterna orsakar i monteringslinjen. Ingen ombalansering på de andra produkterna gjordes, men det togs hänsyn till andra produkter så att balanseringen av den produkten inte leder till extra obalans på de andra produkter i linan. Det var viktigt för fallföretaget att kunna implementera en lösning som inte leder till massa andra förluster. Utifrån de tre lösningarna som föreslagits var denna lösning den mest lämplig för vad företaget önskar sig. En ny layout på produktens stationer har tagits fram. Med denna layout kommer effektiviteten att öka och dötiden minska, och därmed ökas produktiviteten. Förslag tre visar sig att det är möjligt att kunna balansera en mixad-modellmonteringslina, genom att avsluta en produkt och ta ut den tidigare ur monteringslinan.   Nyckelord: Line balancing, manuell montering, balanseringsförluster, mixed products, mixed-model assembly line.

Nowadays, the use of robots in industrial tasks is growing constantly. However, manual assembly is one area that is hard to make fully automated since manual assembly operations work with different shapes and products that require human finesse to do some operations. Humans, on the other hand, have a lot of limitations since this kind of task can be unergonomic and repetitive for operators, which can cause them stress, fatigue, repetitive stress injuries(RSI), and repetitive motion injuries. This project involved designing an insert for the gripper 2F-85 (version 3) that would allow the collaborative robot (UR5) to carry out more assembly tasks in order to relieve human workers of repetitive tasks. The insert has to handle cylindrical shapes in addition to bigger parts that the actual insert cannot handle due to its parallel stroke. For that, a detailed market analysis and insert research were conducted in the initial study. The new insert was then developed using a double-diamond design process. The needs were ranked using the Moscow prioritization method, and ideas were then generated using the brainstorming technique. The final concept was chosen using the weighted decision matrix method. After the final concept selection, computer-aided design (CAD) technology was employed to create the new insert's 3D model and its technical specifications. The mechanical behaviour of the new insert was analysed to reflect its range of workability, expressing the maximum force that it can withstand on each of its grip work surfaces without presenting plastic deformation. For this study, finite element analyses were conducted following the general method for linear structural analysis using Abaqus. Achieving an insert that can reach, transport, and assemble different shapes will help integrate collaborative robots into manual assembly processes, avoiding the cost of a new gripper.