The society today lives on the philosophy of ‘take-make-use-dispose.’ In the long run, this is not sustainable as the natural resources and the waste carrying capacity of the earth are limited. Therefore, it is essential to reduce dependency on the natural resources by decoupling the growth from the consumption. In this venture, both the society and the manufacturing industry have a vital role to play. The society needs to shift towards Circular Economy that rests upon the philosophy of ‘take-make-use-reuse’ and the manufacturing industry has to be a major stakeholder in this shift. Despite being proven to be both economically and environmentally beneficial, successful examples of circular systems are few today. This is primarily due to two reasons; firstly, there is a lack of systemic and systematic approach to guide industries and secondly, there is a lack of analysis methods and tools that are capable of assessing different aspects of circular manufacturing systems. Taking on to these challenges, the objective of this research is to bring forward a framework with methods and decision support tools that are essential to implement circular manufacturing systems. The initial conceptual framework with the systemic approach is developed based on extensive review and analysis of research, which is further adapted for industrial implementation. Systematic analysis methods, decision support and implementation tools are developed to facilitate this adaptation. This development has been supported by four cases from diverse manufacturing sectors. Behind each decision support tool, there are analysis methods built upon mainly system dynamics principles. These tools are based on simulation platforms called Stella and Anylogic. Among other things, these tools are capable of assessing the performance of closed-loop supply chains, consequences of resource scarcity, potential gains from resource conservation and overall economic and environmental performance of circular manufacturing systems.

Purpose

The question of resource scarcity and emerging pressure of environmental legislations has brought a new challenge for the manufacturing industry. On the one hand, there is a huge population that demands a large quantity of commodities; on the other hand, these demands have to be met by minimum resources and pollution. Resource conservative manufacturing (ResCoM) is a proposed holistic concept to manage these challenges. The successful implementation of this concept requires cross functional collaboration among relevant fields, and among them, closed loop supply chain is an essential domain. The paper aims to highlight some misconceptions concerning the closed loop supply chain, to discuss different challenges, and in addition, to show how the proposed concept deals with those challenges through analysis of key performance indicators (KPI).

Methods

The work presented in this paper is mainly based on the literature review. The analysis of performance of the closed loop supply chain is done using system dynamics, and the Stella software has been used to do the simulation. Findings The results of the simulation depict that in ResCoM; the performance of the closed loop supply chain is much enhanced in terms of supply, demand, and other uncertainties involved. The results may particularly be interesting for industries involved in remanufacturing, researchers in the field of closed loop supply chain, and other relevant areas. Originality The paper presented a novel research concept called ResCoM which is supported by system dynamics models of the closed loop supply chain to demonstrate the behavior of KPI in the closed loop supply chain.

One of the most important problems in the production and inventory planning field, is the scheduling of production and work force in a dynamic environment. Although this problem can be formulated as a linear program, it is often quite difficult to solve directly, due to its large scale. Instead, it might be fruitful to use a decomposition approach. Decomposition, in general, means decomposing a difficult problem into several easier, or a sequence of easier problems which are later coordinated to reconstruct the original problem.In this report we discuss several possibilities of applying the most common decomposition principles, namely Benders (primal) and Datnzig-Wolfe (dual), as well as a relatively new decomposition method, called cross decomposition, to the dynamic, multiproduct production and employment planning problem. A number of special cases are also presented.

In this paper the resemblance is demonstrated between the master- and subproblems generated by the Kornai-Liptak algorithm and the subproblems obtained by using the cross decomposition method on linear optimization problems with block-angular structure. The significance of the similarity between these two algorithms becomes apparent considering the main disadvantage attributed to cross decomposition. In cross decomposition a master problem has to be solved from time to time since the subproblems alone do not always give a converging sequence of primal and dual solutions. But if the cross decomposition algorithm is modified in such a way that the successive primal and dual subproblem solutions are taken into consideration with equal weights, this results in the Kornai-Liptak algorithm for which convergence is guaranteed

Målsettingen for licentiatuppsatsen er å analysere nordisk kvinneforsknings formuleringer av forskningspolitiske felter, problemstillinger og utfordringer, og gjennom kontakt og diskusjon bidra til samarbeid, diskusjoner og offentlighet om forskingspolitikk i kvinneforskning. Arbeidet har tatt utgangspunkt i relativt nytt materiale fra Danmark, Norge og Sverige. I kap. 1 presenteres prosjektet, problemstillinger og materiale. Kapitlene 2-6 består av innledninger og artikler holdt eller skrevet i løpet av de to senaste åren. Diskusjoner om kjønn og akademia står i fokus i kap. 2 - "Universities have politics". I kap. 3, artikkelen "Gamle og nye drømmer", diskuteres et kvinneforskningspolitiske intervensjonsprosjekt som blev utført for en del år tilbake, og det antydes noen nye omdreiningspunkter for et slikt arbeid. Enkelte perspektiver utdypes i kap. 4, "Kvinneforskningens samfunnskontrakt", hvor termen "kvinneperspektiv" som forskningspolitisk term granskas krtitiskt. De to siste kapitlene tar utgangspunkt i den norske forskningsmeldingen som kom våren 1999. Ut fra tre lesestrategier forsøkes det leses muligheter for kvinneforskningspolitiske strategier. Det ses også på innholdet i regjeringens forskningspolitiske verdidebatt, og det diskuteres mulige intervensjoner i denne ut fra feministiske vitenskaps- og teknologistudier.

Prolonged computer use, especially if fatigue ensues, is associated with visual and musculoskeletal symptoms. The aim was to determine the time-course of perceived fatigue in the wrist, forearm, shoulder and eyes during a 60-min mouse task (painting rectangles), and whether object size and/or mouse use demands were of influence. Also, we investigated performance (number of rectangles painted), and whether perceived fatigue was paralleled by local muscle fatigue or tissue oxygenation. Ten women performed the task for three conditions (crossover design). At condition 1, rectangles were 45 × 25 mm, square paint cursor size 1.3 × 1.3 mm, and mousepointer movement ratio 1:26. At condition 2, the same cursor size and mousepointer movement ratio was used, but rectangles were smaller. At condition 3, the smaller rectangles were used, but the cursor size was also smaller and mousepointer movement ratio was 1:8. The results showed increased self-reported fatigue over time, with the observed increase greater for the eyes, but no change in physiological responses. Condition 2 resulted in higher performance and increased eye fatigue. Perceived fatigue in the muscles or physiological responses did not differ between conditions. In conclusion, computer work tasks imposing high visual and motor demands, and with high performance, seemed to have an influence on eye fatigue. 

With the increase in food consumption, new ideas, and technologies began to be developed. Inaddition, the developments generated by Industry 4.0 technologies have started to be applied tothe entire manufacturing sector and the indoor farming industry, which is currently trending.Many studies and articles have been prepared on this subject, and the main goal of each study isto produce quality products and to ensure continuity in production to cover the nonendingincrease in demand.

This paper discusses how simulation technology, which is one of the industry 4.0 technologies,can be used in the production system development of the indoor farming industry. According tomany researchers, the biggest obstacle for the vertical farming industry is start-up cost, andsimulation technologies can be the solution for this since it allows future production systems tobe analyzed without any investment. To have a clear vision of how these technologies can beadapted in the indoor farming industry, this paper will find the answers to these questions, RQ1:How can simulation facilitate production system development and Industry 4.0 projects withinthe indoor farming industry? RQ2: What are the benefits and challenges when using simulationas a tool for production system development within the indoor farming industry? To reach thegoal of this paper, the case study method was used, and an indoor farming company was selectedto get more realistic data about the vertical farming system. BlueRedGold AB is a start-upcompany in the indoor farming industry, and it has a huge growth potential since they aim totransform its current production lines to be fully automated. Many articles and studies were usedto approach the solution of the research questions from a more technical and academic point ofview, and the analysis of these articles was carried out with the structured literature review method.

After conducting this research, answers have been obtained for the research questions. Theauthors' solution to the layout issue, one of the case company's main challenges as indicated inthis study, was developed after extensive simulation model testing. As highlighted in this paper,it has been stated by many researchers, there are several simulation approaches to follow.However, the authors have developed a simulation modeling approach to be followed in theindoor vertical farming industry to overcome the complexity of these systems as well as thesimulation program complexity. In addition, several challenges and benefits have beenhighlighted in this paper such as the lack of ready models of the equipment used in indoorfarming which requires a knowledge of a programing language to overcome. Finally, despitechallenges, simulation technology can provide an applicable solution for production systemproblems of vertical farming companies/organizations to obtain continuous improvementphilosophy which is the main principle of Lean thinking. The generated simulation model in thisthesis project was successfully implemented, demonstrating how this technology might be aneffective solution for complex production systems as in the indoor farming sector. 

The purpose of this study is to improve the production flow in a mixed-model assembly line. This has been achieved by first identifying the problems in a mixed-model assembly line and proposing the solutions that can be applied to the problems. In addition, the purpose will be fulfilled with the help of the existing studies and by answering the research questions.

Studien syftar till att skapa djupare förståelse för chefers upplevelse, av deras organisatoriskaoch sociala arbetsmiljö. Studien syftar även till att undersöka chefers uppfattning om defriskfaktorer som de upplever som hälsofrämjande. Uppsatsens huvudfrågeställning är; “Hurupplever chefer sin organisatoriska och sociala arbetsmiljö?” Då tidigare forskning oftafokuserat på preventiva faktorer, inriktar sig denna studie på ett hälsofrämjande perspektiv.Vilket syftar till studiens andra frågeställning; “Vilka friskfaktorer upplever chefer somhälsofrämjande?” Studien tillämpar kvalitativ metod genom semistrukturerade intervjuer förinsamling av empiriskt material. Urvalet består av åtta första linjens- och mellanchefer inomolika branscher. Studien har ett explorativt fokus i syfte att skapa underlag till vidareforskning.Studiens resultat visar på att återhämtning, kommunikation, kollegor, sociala relationer,tydliga roller, mål och arbetsuppgifter upplevs som viktiga organisatoriska och socialaaspekter i chefens egna arbetsmiljö.

Resultatet visar vidare på att upplevda friskfaktorer ärflexibilitet i arbetstid, att bli hörd, kollegors stöd, fungerande sociala relationer ochåterhämtning genom att anpassa sina möten.

En pågående fråga för företag idag är möjligheten att leverera ett brett sortiment av produkter, med kort ledtid och till låg kostnad. Det innebär att större krav ställs på att företagen ska ha en hög produktmix- och volymflexibilitet samtidigt som de håller hög effektivitet. För att uppnå detta krävs att företagen bland annat belyser de okända förlusterna i sin organisation och produktionsprocess för att sedan minimera dessa.

Denna studie har tagit plats på ett industriellt företag som heter Corroventa avfuktning AB och är beläget i Bankeryd, Sverige. De specialiserar sig bland annat på produkter som används för att avfukta byggnader och neutralisera radonstrålning.

Företaget producerar i huvudsak mot lager, väderförhållanden som skapar översvämningar och fuktskador kan driva upp efterfrågan till en punkt som företaget inte kan uppfylla med en tillräckligt kort ledtid för att vinna kundorder. Detta sätter press på Corroventa till att effektivisera och utveckla produktionen för att öka flexibiliteten och minska ledtiden.

Fallstudien har genomförts på en avdelning som kallas för insatsmontering, denna avdelning är en förmonteringsenhet till slutmontering av produkten adsorptionsavfuktare. Avdelningen har identifierats som en begräsning för hela systemet när hög efterfrågan råder, därför har undersökningen utförts för att identifiera de underliggande problemen som orsakade begräsningen och ge förbättringsåtgärder på dessa.

Med en nulägesanalys och ett teoretiskt ramverk som grund har författarna identifierat områden på avdelningen som kan effektiviseras. Rekommendationsförslagen inkluderar en ny produktionslayout, en mer balanserad monteringsprocess samt en minskning av materialhanteringen. Dessa förslag kommer att förbättra avdelningens produktmix- och volymflexibilitet samtidigt som ledtiden reduceras.

Som ett sista steg har en diskussion och slutsats skrivits för att diskutera studiens validitet och reliabilitet, därefter sammanfattas förbättringsförslagen och föreslagna framtida studier som kan genomföras för att ständigt förbättra verksamheten.

ABSTRACT

Purpose: The aim of the work is to map the ergonomics in a production cell and propose and compare the solutions to identified problems. In order to identify the problem and come up with some solutions, these questions have been answered.• What factors lead to operations that are harmful to the body?• How can a production cell be designed to be more ergonomic for employees?• What are the advantages / disadvantages of ergonomics in a production company?

Method: To perform the study and achieve the purpose of the work, the authors used a case study company where observations were made in parallel with a literature review mainly on ergonomics variety of analysis and quality. The case study company has been used as the basis for the case study where ergonomics are mapped by means of observations, interviews and data that were analyzed by means of literature study done in parallel.

Study results: The study resulted in a survey of ergonomics in a production cell at the case study company and 5 different suggestions for improvement. The production cell on the case study company is a red cell today, which means that the production cell is in a non-accepted position and in need for urgent changes in ergonomics. Factors leading to bad ergonomics and a non-accepted position as Volvo's requirements have been identified. Many heavy lifting and many torque is what has the highest negative impact on the working environment and ergonomics. Lack of adequate lifting tools have led to those not used in the production cell today. This leads to repetitive work and encumbrance at the case study company. Further, also the working height of the paths contributed to an increased workload as operators are in an unnatural posture. All of these factors are the basis of the 5 suggestions for improvement as the study also resulted in. New custom lifting tools, job rotation, reverse the order of the court, new packaging and pallet to the gears and the robot turn. All these proposed solutions lead to reduced stress and improved ergonomics in the production cell as manual lifting and twists are reduced. The solutions also leads to the production cell shifting from a non-accepted position with demands of urgent change to a yellow production cell that requires an action plan for the future.

Implications: The aim of this study was to map the ergonomics in a production cell. With the study in hand, a conclusion is drawn that the aim has been achieved when all three of the questions have been addressed. Factors leading to poor ergonomics are identified. As well the advantages and disadvantages of investing in ergonomics identified and how production cells should be formed. With this information in mind, a number of proposed solutions have been developed.

Recommendations: Further studies on the subject are recommended to increase knowledge and interest. It may be appropriate to carry out more case studies at more industries to strengthen the study’s results and generalizability. Furthermore, studies are recommended where the entire work environment is studied and not only physical ergonomics. By studying the whole working environment and the many factors that interact it can lead to a greater force being created for higher efficiency and quality in production.

Keywords: Ergonomics, Ergonomics, Work, Volvo CE, Load, Lifting Tools, Body Injury, Advantages, Improvements, Quality

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. 

1. Which line balancing problem-solving techniques exist in the literature?
2. Which investment costs can be considered vital for new assembly lines as a    consequence from new product introductions?
3. 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?
4. 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.

Background and aims: World experience has shown the positive effect of applying ergonomics in improving work conditions, of quality and quantity of production, reducing prevalence of work-related musculoskeletal disorders, saving costs and increase of productivity in the different contents. These are possible only with utilizing properly improving work condition system and Macroergonomics approach. The aim of the study was how determine situation and analyzing the working conditions using the macroergonomics approach in a Power Plant Industry. Methods: This study is a cross-sectional study. First, the program for improvement of work conditions were evaluated using three questionnaires including managers viewpoint (29 samples), health, safety and environment employees viewpoint (5 samples) and operating workers viewpoint (85 samples) and then three other instruments of macroergonomics were used. Results: According to the results of 1) questionnaires and corresponding tests, three of the program's goals of improving working conditions and promotion practices that have the same opinions, but in some cases had different opinions. 2) Future workshops and interviews, the lack of participatory leadership and lack of collaborative work systems for the company stated. 3) Apply ergonomics checklist of ILO, an appropriate interaction between the top and bottom surfaces revealed. Conclusion: Awakened needs of change in the middle and lower levels of organization to solve problems relate to improving working conditions of the system was created. To implement an Ergonomics Intervention Programme Technique Process requires the full support management and employees.

Background: Implementing ergonomics principles in workplaces requires good knowledge transfer with the participation of professionals, workers, and managers.

Purpose: This study aimed to investigate practical ergonomics knowledge transfer to support the participatory ergonomics process that could lead problem identification and the implementation and development of feasible and low-cost solutions.

Methods: This was action research on the type of intervention and conducted in four phases. Accordingly, 106 participants from different organizational levels of a manufacturing company, facilitated by an ergonomist by forming 14 action groups, were involved in practical ergonomics knowledge transfer to identify and solve problems of work divisions. Participant reflections were obtained through interviews and field notes.

Results: The results contributed to the presentation of 145 solutions to improve working conditions by the action groups. Most solutions were low-cost and 57.5% were implemented. The interviews showed the development of a participation culture, learning and institutionalizing ergonomics principles in practice, and improving competence in identifying problems and implementing solutions.

Conclusions: The key findings were achieved by the participatory ergonomics intervention approach through different tactics of participant engagement, including a pushing tactic for intentional learning and a pulling tactic for voluntary learning, which resulted in the improvement of working conditions and promotion of a participatory culture.

OCCUPATIONAL APPLICATION

We found that small business enterprises (SBEs) face intra- and extra-organizational barriers in different dimensions related to their work system to practically implement human factors/ergonomics (HFE) knowledge transfer and to achieve its benefits in an industrially developing country. Utilizing a three-zone lens, we evaluated the feasibility of overcoming the barriers identified by stakeholders, especially ergonomists. To overcome the identified barriers in practice, three types of macroergonomics interventions (top-down, middle-out, and bottom-up) were distinguished through macroergonomics theory. The bottom-up approach of macroergonomics, as a participatory HFE intervention, was considered as the entry point to overcome the perceived barriers in the first zone of the lens, which included such themes as lack of competence, lack of involvement and interaction, and inefficient training and learning approaches. This approach focused on improving emotional literacy as a care zone among the small business enterprise personnel.

TECHNICAL ABSTRACT

Background: The human factors/ergonomics (HFE) knowledge transfer process is one of the potential challenges for organizations in industrially developing countries (IDCs), especially in small business enterprises (SBEs).

Purpose: We explored perceived barriers and challenges to the practical implementation of HFE knowledge transfer to SBEs in Iran, as an IDC, to improve their work systems.

Methods: An exploratory qualitative study was conducted using a conventional content analysis. To identify perceived barriers, we conducted individual interviews (n = 38) and a focus-group discussion (n = 17) with the participation of the SBEs personnel and the officials of related organizations. Inductive content analysis was used for data analysis. We then categorized the identified perceived barriers (themes) to determine the feasibility of overcoming them.

Results: Regarding perceived barriers, the following nine themes were extracted: lack of competence, resistance to change, technological infrastructure problems, lack of involvement and interaction, using an inappropriate mode of knowledge, lack of culture-building about HFE, inefficient training and learning approaches, lack of scientific management, and extra-organizational problems. Further, a three-zone lens was identified for the extracted themes to check the feasibility of overcoming them.

Conclusions: We identified nine intra- and extra-organizational barriers in the HFE knowledge transfer process to SBEs. We further evaluated the ways of overcoming perceived barriers defined in the three-zone lens to adapt them for building creative workplace culture zones (care, creative, and improvement). We distinguished three types of macroergonomics interventions (top-down, middle-out, and bottom-up) and three supporting strategies, including, knowledge, management and employees, and participatory HFE.

Introduction: This study aims to evaluate the risk factors and the prevalence of WMSDs disorders using QEC and Body Map techniques in operational units took a gas refineries and its Meta-Reflection.Method and Material: This case study assessed 254 operators in three distinct phases. First, 72 workstation posture was evaluated by using of QEC. Secondly was intended for employees of WMSDs were assessed using by Body Map. After conducting interview with relevant directors, the effectiveness of such studies has been analyzed through Meta-Reflection.Results: Based on results came from QEC survey, the operators’ average scores was %53/8. Moreover, results of Body Map assessment showed that the highest organs of WMSDs were back and knee extrusions (47% and 46% respectively). Also, lack of ergonomics policy and plan within refinery has demonstrated by interviews. Meta-Reflection, on the other hand, showed that because of incomplete learning cycles in the mentioned surveys which only provide WMSDs’ status, workstations’ ergonomics condition, and introduce expert based solutions. Thus, such surveys not only have incomplete study plan, but also have less impact on improving overall health, safety and ergonomics within this organization.Conclusion: This research proves that non-ergonomic conditions result in awkward postures and subsequent physical disorders. Overall, this study has showed a gap from this kind of the work on the learning cycles at organizational levels, a trend should be considered to interactive research work on the workplaces with improved and promoted system ergonomics attitude.

In today’s dynamic business environment, a key challenge for all companies is to make adaptive adjustments to their manufacturing strategy. This study demonstrates the competitive priorities of manufacturing strategy in hydro-power case company to evaluate the level of sustainable competitive advantage and also to further analyze how business strategies are aligned with manufacturing strategies. This research is based on new holistic analytical evaluation of manufacturing strategy index, sense and respond, and sustainable competitive advantage models. These models help to describe, evaluate, and optimize resource allocation to meet the performance requirements in dynamic decision making. Furthermore, these models evaluate operational competitiveness for manufacturing strategies according to the multi-criteria priority. The results show that the adjustments of competitive priorities in manufacturing strategies by implementing the proposed holistic analytical models are helpful in strategically managing business operations. The discussion derives the most critical attributes in business operations while alignment of resource allocation with competitive priorities help to strategically focus those attributes. In conclusion, we argue that resource allocation and manufacturing strategies have become the most important capabilities in a business environment where companies focus to get a sustainable competitive advantage.

Volvo Powertrain Skövde är en fabrik som tillverkar lastbils- och bussmotorer i olika volymer. Fabriken har flera avdelningar och funktioner som tillsammans uppgör de tre huvuddelarna: gjuteri, bearbetning och montering. En av dessa avdelningar är logistikavdelningen, vars uppgift är att organisera interna logistiska aktiviteter på företaget. Logistikavdelningen eftersträvar att tillgodose god kundservice med låga kostnader och låg miljöpåverkan. Detta arbete rör delar av logistikavdelningens nuvarande datahanteringssystem för lagerhantering. Det nuvarande systemet har bristande användarvänlighet och gör det svårt att överblicka lagerytor. Dessa, och fler problem får logistikavdelningen att uppleva systemet som tidskrävande och bristfälligt. Syftet med detta arbete var att framställa lösningsförslag som åtgärdar bristerna i det nuvarande systemet, utan att kräva större investeringar och underlättar datahanteringen samt ger bättre visualisering över lagerlokalerna. Metoderna som valdes för att uppnå arbetets syfte motiveras från en utförd litteraturstudie.

För att jämföra lösningsförslag, användes standard IEEE-830 som grund för framtagning av en kravspecifikation. Kravspecifikationen bygger på observationer och intervjuer som utfördes med logistikavdelningen. De lösningsförslag som presenteras bygger på intervjuer med anda sajter inom Volvokoncernen, lösningsförslagen jämförs även mot kravspecifikationen för att se hur väl de passar logistikavdelningens behov. Metoderna som använts under arbetets utförande diskuteras även och avslutningsvis framförs rekommendationer för framtida arbete.

Syftet i vår undersökning är att undersöka skillnader mellan mäns och kvinnors upplevelse av den psykosociala arbetsmiljön. För att kunna uppnå vårt syfte har följande frågeställning utformats: Är det någon skillnad mellan män och kvinnors upplevelse av stress, mobbning, sexuella trakasserier, socialt stöd, chefsstöd och autonomi i deras arbetsmiljö? Studien har utförts via vår webbenkät på sociala medier, Facebook och LinkedIn. Vår metod har varit av kvantitativ art och genomförts med 112 respondenter. För att få så många svar som möjligt har vi delat enkäten offentligt och via Messenger med vänner som kunde ta del av den. Motiveringen till att detta material används i denna studie är att det kan bidra till en förståelse för respondenternas upplevelse av stress, mobbning, socialstöd, chef stöd, sexuella trakasserier, autonomi, inflytande och egenkontroll, samt för att kunna jämföra skillnader mellan män och kvinnor i dessa avseenden. Resultatet avslöjade inga skillnader mellan män och kvinnor som var statistiskt säkerställda Eftersom respondenterna i studien har deltagit på eget initiativ avviker de sannolikt från populationen i sin helhet avseende intresse för och erfarenheter av könsskillnader och frågor om arbetsmiljö. Resultatet kan därför inte generaliseras till andra grupper i samhället. Vidare forskning bör använda sig av randomiserade urval för att undersöka könsskillnader gällande stress, mobbning, sexuella trakasserier, socialt stöd, chefsstöd, autonomi, inflytande och egenkontroll.

We deal with a multi-echelon inventory system in which one warehouse supplies an item to multiple retailers. Customer demand arrives at each retailer at a constant rate. The retailers replenish their inventories from the warehouse that in turn orders from an outside supplier. It is assumed that shortages are not allowed and lead times are negligible. The goal is to determine replenishment policies that minimize the overall cost in the system. We develop a heuristic to compute efficient policies, which also can easily be used in a spreadsheet application. The main idea consists of finding a balance between the replenishment and the inventory holding costs at each installation. This new heuristic we compare with two other approaches proposed in the literature; the computational studies show that in most of the instances generated the new method provides lower costs.

The question of resource scarcity and emerging pressure of environmentallegislations have put the manufacturing industry with a new challenge. On theone side, there is a huge population that demands a large quantity ofcommodities, on the other side, these demands have to be met by minimumresources and with permissible pollution that the earth’s ecosystem can handle.In this situation, technologic breakthrough that can offer alternative resourceshas become essential. Unfortunately, breakthroughs do not follow any rule ofthumb and while waiting for a miracle, the manufacturing industry has to findways to conserve resources. Within this research the anatomy of a large body ofknowledge has been performed to find the best available practices for resourceconservation. Critical review of the research revealed that none of the availablesolutions are compatible with the level of resource conservation desired by themanufacturing industry or by society. It has also been discovered that a largegap exists between the solutions perceived by the scientists and theapplicability of those solutions. Through careful evaluation of the state-of-theart,the research presented in this thesis introduced a solution of maximizingresource conservation i.e., material, energy and value added, as used inmanufacturing. The solutions emerged from the novel concept named asResource Conservative Manufacturing, which is built upon the concept ofMultiple Lifecycle of product. Unlike other research work, the researchdocumented in this thesis started with the identification of the problem andfrom which a ‘wish to do’ list was drawn. The seriousness of the problem andpotential of adopting the proposed concept has been justified with concreteinformation. A great number of arguments have been presented to show theexisting gaps in the research and from that, a set of solutions to conserveresources has been proposed. Finally, one of the prime hypotheses concerningclosed loop supply chain has been validated through the system dynamicsmodeling and simulation.

The transition towards a circular economy (CE) has become inevitable to mitigate challenges of resource scarcity and resource price volatility, as well as minimize the climate and environmental impact. By 2030 for the EU, CE could result in a reduction of primary material consumption by 32% [1]  and greenhouse gas emissions by 48 % compared with the 2012 levels[2]. The European Environment Agency[3] estimates that the net benefits for businesses by implementing CE measures range from EUR 245 billion to EUR 604 billion. Although these figures are promising the reality is rather bitter. Remanufacturing[4] which is one of the most important strategies in implementing CE principles in the manufacturing industry, has an intensity (ratio of remanufacturing to new manufacturing) of only 1.9%, while the intensity in the automotive sector is 1.1% in the EU[5]. This means that the remanufacturing intensity in all sectors needs to be increased significantly to exploit the untapped potential of CE. 

At Scania and many other Original Equipment Manufacturers (OEMs) and Suppliers (OESs), the flow of new components for the production of new vehicles is handled independently from the flow of remanufactured components that are intended for the aftermarket. The gearbox is one such component. For any company to intensify its circularity to the level that society needs without cannibalising the aftermarket business, integrating remanufactured components in the production of new products is essential[6]. However, OEMs have thus far not attempted to systematically integrate remanufactured components in the new products.

The iReGear project presents the first successful demonstration of integrating a remanufactured gearbox into the production line of new trucks and serves as an objective demonstration that the remanufactured gearbox performs as good as a new one. The project also investigated and confirmed that there are no legal obstacles to using remanufactured components in new trucks, provided that customers are informed about it. Additionally, it has been established that there are no existing examples of remanufactured components being used in new vehicles.

Two major Scania customers have indicated their willingness to accept remanufactured components in new trucks, as long as the performance and competitiveness of the trucks are not compromised. They also expressed a readiness to pay more for such a solution, given that it reduces overall emissions, and their customers are willing to pay for these added environmental benefits.

An attempt has also been made to formulate two basic equations and a procedure to estimate the economic and environmental potential of scaling up the use of remanufactured gearboxes in new trucks. Moreover, it is also estimated that the current remanufacturing intensity of the gearbox is only 0.4% relative to the number of new gearboxes produced by Scania each year indicating a significant potential for increasing the volume of remanufactured gearboxes.

This research makes a significant contribution to the ongoing discussion and provides the first evidence to support the argument that it is feasible to envision future manufacturing organizations seamlessly integrating manufacturing and remanufacturing operations to develop Circular Manufacturing Systems that consume fewer resources, produce fewer emissions, and cost less without compromising quality and performance. Future research should advance with a vision toward a Circular Manufacturing System, where the integration of remanufactured components becomes the status quo. Along the way, efforts should also focus on enhancing the efficiency of remanufacturing by addressing the shortcomings of conventional approaches.

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 [1] Ellen MacArthur Foundation, n.d. The circular economy in detail, Deep dive [WWW Document]. URL https://ellenmacarthurfoundation.org/the-circular-economy-in-detail-deep-dive#:~:text=The (accessed 3.8.23).[2] McKinsey, 2015. Europe’s circular economy opportunity. McKinsey& Co. 1–7.[3] European Environment Agency, 2016. Circular economy in Europe - developing the knowledge base, Publication Office of the Euopean Union.[4] Remanufacturing is not the same as reparing, recycling or refurbishing. It is about reusing components of an existing product to create a new product with a full warranty, to be sold as new or remanufactured. They are almost indistinguishable from new parts.[5] Parker, D., Riley, K., Robinson, S., Symington, H., Tewson, J., Jansson, K., Ramkumar, S., Peck, D., 2015. Remanufacturing Market Study, European Remanufacturing Network. https://doi.org/EC--09 404 ERN WP2.2.docx[6] Rashid, A., Asif, F.M.A., Krajnik, P., Nicolescu, C.M., 2013. Resource conservative manufacturing: An essential change in business and technology paradigm for sustainable manufacturing. J. Clean. Prod. 57. https://doi.org/10.1016/j.jclepro.2013.06.012

To ensure multiple-lifecycle of products through remanufacturing intervention requires a well-functioning closed-loop supply network. Generally, the unpredictability of quantity, timing and quality (physical/functional) of the returned products and demand fluctuation of the remanufactured products are the main sources of uncertainty of closed-loop supply network. To some extent, efficient recollection strategies and separate distribution channels for remanufactured products can minimize the uncertainty. Nevertheless, efficient recollection does not necessarily close the loop if the recovered products do not enter into the main stream of the supply network. Beside, products that are distributed through separate channels create an open loop. Thus, the problem of uncertainty remains unsolved. The aim of this paper is to propose solutions to minimize the uncertainty involved in designing a well-functioning closed-loop supply network using the system dynamics principle and tool.

The transition towards a circular economy has become important. Manufacturing industry being a major stakeholder in this transition has started exploring the potential of this transition and challenges in implementation. Ambitious companies such as Gorenje d.d. has taken the circular economy transition seriously and aims to become a pioneer in implementing circular manufacturing systems. One vital step in this transition is the business model shift from the linear (sales model) to a circular model such as 'product as a service'. This brings new challenges to Original Equipment Manufacturers (OEMs) that have never been experienced in their conventional businesses. One of the challenges is to establish an information communication and technology (ICT) infrastructure that enables information management and sharing as well as establishes a real-time communication between relevant stakeholders. Outlining such an ICT infrastructure is the objective of this paper.

Circular Economy (CE) promotes trading functions of a product as aservice instead of selling the product in conventional ways. For a product like ababy stroller, the function means ensuring mobility with infants without needingto own a stroller. This approach of acquiring functions only when needed opensup the possibility to share the same products with multiple users. For a manufacturer that has built its business on a conventional sales model over the decades,this shift may be too radical. Therefore, for the manufacturers, it is important tounderstand consumer perceptions of the service-oriented business model beforeentering this unknown territory. To develop a thorough understanding of consumerperceptions of leasing a stroller instead of buying one, a survey among 200 parentsin Stockholm is conducted. The survey brings out quantitative results such as 39%of respondents are open to leasing and identifies key influencing factors such asconvenience and environmental image that play a key role for the remaining 61%of respondents to choose leasing. This research concludes that a large numberof consumers are open to leasing if a high level of service and environmentallysustainable strollers are offered at a competitive price.

The Design for Repeatedly Utilization (DFRU) is a proposed conceptto be used in the product realizationprocess to ensure optimum useable life (forinstance in terms of economy, resourceusage, environmental impact etc.) ofproducts or parts of products enablingmultiple lifecycle. In the DFRU approachproducts are restored as new like productsthrough remanufacturing processes. Theterm remanufacturing has been interpreteddifferently by different researchers and theindustries that are involved inremanufacturing business use differentapproaches to remanufacture theirproducts. In this paper the starter motorand alternator of automotives has beenused to demonstrate the novel concepts.The purpose of this paper is to expresswhat remanufacturing means in ourconcept, model their major lifecycleaspects and create a simulation modelfrom it. This is a preliminary work towardsdefining and specifying the processes,methods and design properties in DFRU.The work will be further extended to aholistic business model which can facilitateDFRU approach in an efficient way. Infuture the model will be developed andadopted to create new models for otherproducts appropriate for remanufacturingand eventually DFRU.

This thesis presents the approach of determining the machining  errors on a five axis CNC machine using sensors already fitted in the machine to extract valuable data up on process called CITE(CNC Integrity Tracing Equipment) system and measuring the machined workpiece geometry using CMM(Coordinate measurement machine). CITE measurement system is the data acquisition hardware and software system developed by University West for collecting position information from encoders of a machine tool. The collected information could then be used to assess the quality and adjustment of a machine tool, CNC programs and the CNC control parameters. The aim of this study is to examine the roundness and concentricity detection capacity of the CITE system by conducting different milling methods and a turning process. In an example cutting of a workpiece, the CITE measurement system was used for recording the machining process. After that, radial error, centre point deviation and circle roundness errors, analysed using MATLAB based on collected CNC tool movement data. CMM measurement used to verify the results obtained from the CITE measurement system. The investigation conducted on the small circles shows that the CITE measurement system have capability of identifying radial errors in different method of millings (slot, up and down). Centre point deviation and roundness errors measured by the CITE system doesn`t show significant differences between milling methods as seen on CMM measurement.

The use of a personal protective device (ppd) is a widely accepted method of safeguarding workers from occupational hazards in industrialized countries (IC) and an important method employed in developing countries (DC). Though protection is assured if the devices are worn constantly, it is unfortunate that due to discomfort and inconvenience, the majority of those exposed to hazards do not wear them. DCs which mainly import ppds from ICs are confronting many ergonomics problems, because the equipment designed for IC conditions is inappropriate for use in DCs, due to significant differences in user body sizes, environments and working methods. A questionnaire survey conducted among ppd manufacturers in 11 ICs revealed that 90% followed standards in manufacturing. Another survey conducted among health and safety authorities who responded on behalf of ppd users in 35 DCs revealed that the most common ergonomic causes of non-use are stresses from hotness, weight, improper fit and obstruction at work. While manufacturers place greater emphasis in the protection performance of the equipment, users in DCs refuse to wear it because the comfort needs are not fulfilled. Developing ergonomics standards for ppds seems to be a feasible way of persuading the manufacturers to provide ergonomic values in ppds. The need for maximum allowable comfort in the design, taking into consideration the user characteristics and protection factor is emphasized. To overcome the inherent discomforts that are extremely difficult to reduce without compromising the protection efficiency of a ppd, the principle of user adaptation seems to be a very important facet which has to be developed. A case study on safety helmets is reported. The use of a personal protective device (ppd) is a widely accepted method of safeguarding workers from occupational hazards in industrialized countries (IC) and an important method employed in developing countries (DC). Though protection is assured if the devices are worn constantly, it is unfortunate that due to discomfort and inconvenience, the majority of those exposed to hazards do not wear them. DCs which mainly import ppds from ICs are confronting many ergonomics problems, because the equipment designed for IC conditions is inappropriate for use in DCs, due to significant differences in user body sizes, environments and working methods. A questionnaire survey conducted among ppd manufacturers in 11 ICs revealed that 90% followed standards in manufacturing. Another survey conducted among health and safety authorities who responded on behalf of ppd users in 35 DCs revealed that the most common ergonomic causes of non-use are stresses from hotness, weight, improper fit and obstruction at work. While manufacturers place greater emphasis in the protection performance of the equipment, users in DCs refuse to wear it because the comfort needs are not fulfilled. Developing ergonomics standards for ppds seems to be a feasible way of persuading the manufacturers to provide ergonomic values in ppds. The need for maximum allowable comfort in the design, taking into consideration the user characteristics and protection factor is emphasized. To overcome the inherent discomforts that are extremely difficult to reduce without compromising the protection efficiency of a ppd, the principle of user adaptation seems to be a very important facet which has to be developed. A case study on safety helmets is reported.

The use of personal protective devices (ppd) is an important method to safeguard workers from occupational hazards both in industrialized and developing countries. Surveys have indicated that majority of those exposed to hazards are reluctant to use ppd because they are uncomfortable for such reasons as hotness, heaviness, ill fit, inconvenient, etc. Investigations have revealed that user-centered designs which satisfy the human factors needs of ppd, can reverse this trend and make ppd more acceptable. Because a questionnaire survey has shown that manufacturers are more inclined to adhere to standards, developing ergonomic standards seems to be a feasible method to persuade the manufacturers to provide the user needs in the design. Any unavoidable discomforts in ppd can be controlled by adaptation of users to ppd wearing.  

Då personlig skyddsutrustning (Personal Protective Devices, ppd) används i kallt klimat blir problemen med användarvänlighet mer påtagliga eftersom ppd måste bäras utanpå skyddskläder mot kyla. Forskningen inom området ergonomiska aspekter på ppd i kallt klimat har på senare tid varit bristfällig. Den ppd som idag används i kallt klimat uppfyller inte kraven på användarvänlighet vilket har resulterat i obekväma kläder, skador, oanvändbara kläder samt ett minskat användande av ppd bland utomhusarbetare, speciellt i extremt kalla områden såsom artiska länder. En preliminär studie gjordes angående användningen av ppd i kallt klimat och omfattade de litteraturkartläggning, en enkätundersökning gjord bland utomhusarbetare samt informationssökning genom besök hos relevanta forskningsinstitut, diskussioner med forskare och deltagande i konferenser. Litteratursökningen, som utfördes i sex databaser, gav mycket nyttig information om de speciella områden där det finns problem med användarbarheten hos ppd liksom användbar information om forskningsmetoder. Enkätundersökningen, som utfördes i Luleå regionen, bekräftade att arbetarna ställdes inför många problem vid användande av ppd i kallt klimat. Enligt vad som framkommit i denna studie är de tre viktigaste typerna av ppd skyddshandskar, skyddsskor och skyddshjälmar vilka diskuteras i denna rapport. Det finns ett stort behov av forskning inom området ergonomiska faktorer på ppd som används i kallt klimat där en förbättring av användarvänligheten hos skyddsutrustningen är ett mål.

An extraordinarily large share of research carried out in the near past on clothing comfort has been in the area of thermal comfort. Accordingly standards, norms and guidelines on thermal requirements of work-wear have been developed. Through behavioural adjustments people have learned to achieve thermal comfort even if the work clothes have slight deficiencies in thermal characteristics. It is beyond doubt that the thermal characteristics need careful consideration in the manufacture of work clothes. At the same time one must be aware that other human factors can also influence the overall wearability of clothing. This paper reviews the wearability and comfort of the clothing and work-wear to provide better understanding of the priorities in user needs in work clothes which can help plan future research and the need for new standards

The human factors or wearability needs of personal protective devices (ppd) and clothing (ppc) worn in the cold environment become more important as they must compromise with, and be adapted to, the clothing worn for cold protection. The occupational risks among outdoor workers in the cold can be aggravated if the wearability demands of ppd are not met. Failure to adequately meet user needs in currently used ppd in the cold environment has resulted in discomfort, injury, non-use and performance decrement among outdoor workers, particularly in the extreme cold regions. A preliminary study consisting of a literature survey in popular data bases and questionnaire survey among users of ppd, were carried out to ascertain what studies have already been conducted in this area and whether a wearability problem really exists among users, respectively. The literature revealed some specific areas where wearability problems exist and some research carried out on methods of testing of ergonomic characteristics of ppd. The questionnaire among ppd users in the cold climate confirmed that the workers do confront many inadequacies in the use of ppd. A case study carried out on ergonomic demands of safety shoes in the cold climate among users, manufacturers and experts revealed a similar trend of demands and priorities in ergonomics of shoes among all three groups. From the findings of the preliminary study it can be concluded that human factors research in ppd and particularly ppd worn on body extremities, viz. safety helmets, shoes and gloves, for use in the cold environment, seem urgent. Some research needs in the development of methods of testing for ppd evaluation are suggested.

Discomfort in the use of personal protective devices (PPD) has been one of the chief causes of their non-use. A field trial using industrial helmets was carried out to ascertain whether by training and repeated wearing subjects could experience a significant adaptation to discomfort. Ten subjects took part in the trial in a tropical environment by wearing helmets repeatedly (6 h a day) for one month. Subjective evaluations of discomfort were made at the end of the 1st, 3rd, 5th, 14th and 30th day. It was revealed that complaints of discomfort, viz. hotness, heaviness, bad fit, etc., decreased markedly throughout the 30 day period. Though positive responses of adaptation to discomfort seem to reach an optimum towards 30 days, it is difficult to draw any conclusions on the optimum period of adaptation for each discomfort factor. In relation to inherent discomforts that are extremely difficult to overcome without compromising the protection efficiency of a PPD, the principle of adaptation seems to be a very important facet which has to be developed for an effective PPD programme.