This diploma thesis deals with a new concept of maintenance and operation of production technologies, where spare parts are manufactured using rapid prototyping methods. The options are compared with currently used methods. Furthermore, methodological recommendations are written on how to proceed with the application. The aim of the work is to evaluate the concept and confirm the theoretical assumptions on a case study.

This thesis studies the problem of modeling life-limited spare units in a steady-state scenario. This means that units that have a predefined lifespan are to be modeled in a scenario where all conditions are kept constant and all transients have faded out. OPUS10 is a spare parts optimization software developed by Systecon AB. There is no way to explicitly model the life-limited units in OPUS10, although there are different approximate models that are built on adjustments of the failure rate and repair fraction or the definition of preventive maintenance. The objective of this thesis is to analyze the usage of life-limited items in real life and to investigate what approximated models different OPUS10 users will utilize in their modeling of life-limited units. Furthermore, the objective is to analyze the consequences of the approximated models and to investigate the possibility of an improved model. The results show that the main interest when choosing which approximated model to use is the type of life limit. There are three different types of operating time life limits investigated. Either the unit is discarded immediately after the life limit is reached, or it is instead discarded at the next failure. There is also the possibility of resetting of the life limit timer at each maintenance. In all three cases, it is shown that if choosing the most fitting approximate model, the results are very accurate. If the life limit is instead measured in calendar time, even the best approximation will give an under-estimation of the expected number of backorders. It is also shown that most of the OPUS10 users model life-limited units as preventive maintenance with discard, which is not the best approximation in any of the types of life limits.

Purpose: The purpose of this study was to analyze possible strategies that can be used to improve the efficiency of the spare parts safety stock management in a multinational company which operates in the electronic industry. Research question: “Which safety stock dimensioning strategies are most suitable in an after-sales business environment, characterized by high level customer service and unpredictable demand?” Method: The theoretical framework illuminated the study’s phenomenon which was mainly based on peer-reviewed scientific articles but also academic books. Furthermore, the empirical data collection in this study was conducted through a mixed research approach, where the qualitative data was collected through three semi-structured interviews and several unstructured interviews, while the quantitative data consisted of calculations using numerical variables provided by the case company. Conclusion: The study concluded that the so called estimated safety stock method as well as the probabilistic demand based on history method are the most suitable safety stock dimensioning strategies to utilize in business environments where firms that offer products with unpredictable demand are facing challenges related to finding a balance between providing a high service level and keeping their costs as low as possible. / Syfte: Syftet med denna studie var att analysera möjliga strategier som kan användas för att förbättra säkerhetslagerhanteringen av reservdelar hos ett globalt företag inom elektronikindustrin. Frågeställning: “Vilka dimensioneringsstrategier för säkerhetslager är mest lämpliga i en eftermarknadsverksamhet, kännetecknad av hög servicenivå och oförutsägbar efterfrågan?” Metod: Det teoretiska ramverket belyste studiens fenomen som var baserad på främst expertgranskade vetenskapliga artiklar men även böcker. Vidare genomfördes den empiriska datainsamlingen i denna studie genom en mixad forskningsmetod, där den kvalitativa datan var i form av fyra semistrukturerade intervjuer samt flera ostrukturerade intervjuer, medan den kvantitativa datan bestod av beräkningar med hjälp av numeriska variabler tillhandahållna av fallföretaget. Slutsats: Studiens slutsatser visade att den så kallade manuellt bedömt säkerhetslager metoden samt probabilistisk efterfrågan baserad på historisk data metoden är de mest lämpliga dimensioneringsstrategier för säkerhetslager att använda i affärsmiljöer där företag som erbjuder produkter med oförutsägbar efterfrågan står inför utmaningar relaterade till att hitta en balans mellan att tillhandahålla en hög servicenivå och att ha så låga kostnader som möjligt.

Aim: The aim of this study is to investigate the need for a central warehouse for spare parts distribution in the after-sales market for manufacturing companies. Research question: What are the potential benefits and challenges of a central warehouse for spare parts distribution in the after-sales market for manufacturing companies? Method: This study has been inspired by the deductive approach with a qualitative research design, and with a case study. A literature survey has been carried out, where previous scientific research has been analysed. Empirical data was collected from the case company with interviews in both structured and semi-structured form. Based on an analysis of literature and theory, a conclusion has been drawn up. Conclusion: Both benefits and challenges have been identified, but the study shows that more benefits than challenges have been confirmed. Thus, it can be concluded that a central warehouse will show more value in terms of benefits for companies, but not without facing some challenges on the way.

Additive manufacturing is described in literature as a disruptive technology for spare parts supply chains and shows the potential to impact business models for spare parts production through various advantages over conventional manufacturing. Understanding changes in business models is important for companies to adopt any technology and explore business opportunities around it. This research aims to fill the gap in literature on how business models change when additive manufacturing is used for spare parts production in the automotive industry. To investigate those changes a qualitative research design with semi-guided interviews with experts in automotive companies was chosen. The findings showed that the adoption of additive manufacturing in the automotive industry is generally slow and only a few spare parts are specifically developed for additive manufacturing. Especially for niche low-volume and high-value applications AM is already used. At the same time identifying new business cases is needed for broader adoption. Contrasting opinions in literature that additive manufacturing is a disruptive technology, the adopters referred to it rather as a tool. Moreover, the findings showed that the potential of additive manufacturing described in literature is still there but cannot be utilized yet due to various identified barriers at the current stage. The main identified barriers are lack of knowledge, suitable manufacturing data, and resources to explore additive manufacturing.

Tillverkande företag inom den svenska industrin utnyttjar ofta sina maskiner maximalt för att möta den efterfrågan som råder på deras produkter. Detta leder till slitage på maskinerna och därmed även ett stort behov av att reservdelar och komponenter finns tillgängliga, något som krävs för en fungerande underhållsprocess. Samtidigt binder företagen mycket kapital i sina reservdelslager. För att uppnå skalfördelar och minskade kostnader kan företag överväga att centralisera sina lagerstrukturer. Med anledning av ovan nämnda aspekter, är det av vikt att undersöka möjligheterna till ökad samlagring av reservdelar inom den svenska pappersmassaindustrin.   Syftet med studien är att undersöka förutsättningar för centralisering av reservdelslager.   Baserat på frågeställningarnas karaktär är metodvalet en blandning mellan kvalitativ och kvantitativ metod, med tyngdpunkt i den kvalitativa delen. Arbetets angreppsätt är av induktiv typ, då problemområdet identifierades tidigt och någon teoretisk inhämtning inte skedde förrän senare i arbetsprocessen. En fallstudie genomfördes för att erhålla djupgående och detaljrik information rörande forskningsfrågorna. Dessutom möjliggjorde fallstudien att en blandning mellan den kvalitativa och kvantitativa metoden kunde tillämpas. Datainsamling skedde genom litteraturstudier, dokumentinsamling och intervjuer. Intervjuerna var av semistrukturerad typ och skedde både över telefon samt på plats hos fallföretaget.   Den finansiella aspekten är det mest betydelsefulla motivet för en centralisering och tillika den största fördelen som en sådan omstrukturering medför. Det eftersom det totala antalet reservdel kan reduceras, vilket också minskar en rad kostnader. Därtill visar studien att en centralisering leder till en minskad miljöpåverkan. Hinder för centralisering av förrådsverksamheten är behovet av transparens, standardisering och öppenhet mellan de inblandade parterna. Vidare behövs en rättvis kostnadsfördelning mellan aktörerna, där individuella resultatmål råder.   De reservdelar som lämpar sig för att lagerföras vid ett centrallager är sådana som delas av minst två produktionsanläggningar, som är skrymmande, har högt inköpsvärde och som åldras snabbt.   Med hjälp av en modifierad variant av tyngdpunktsmetoden, har ett centralt beläget lager för fallföretagets samtliga svenska bruk lokaliserats till Örebro med omnejd. Om centrallagret däremot endast avser fallföretagets fyra nordligaste bruk bör lagret enligt den modifierade tyngdpunktsmetoden förläggas till Ludvika. / Manufacturing companies in the Swedish industry often make maximum use of their machines in order to meet the demand of their products. This leads to wear on the machines and thus a great need for access to spare parts and components, which is required for a functioning maintenance process. At the same time, the companies bind a lot of capital in their spare parts inventories. To achieve economies of scale and reduced costs, companies may consider centralizing their inventory structures. In view of the above-mentioned aspects, it is essential to examine the possibilities for increased co-storage of spare parts in the Swedish pulp industry.   The purpose of this study is to examine the conditions required in order to centralise spare part storage.   Based on the nature of the research questions, the choice of method is a mixture between qualitative and quantitative method, with an emphasis on the qualitative part. The approach of the work is of an inductive type, since the problem area was identified early, and no theoretical acquisition took place until later into the research process. A case study was conducted in order to obtain in-depth and detailed information concerning the research questions. This also made it possible to employ a combination of the qualitative and quantitative method. Data collection was done through literature studies, document analysis and interviews. The interviews were of a semi-structured type and took place both over the telephone and on site at the case company.  The financial aspect is the most significant motive for centralization and the biggest advantage that such a change can bring. The reason behind this is that the total number of spare parts can be reduced, which also help to lower costs in other areas. In addition, the study shows that a centralization leads to a reduced environmental impact. Barriers to centralization of the storage operations are the need for transparency, standardization and openness between the parties involved. Furthermore, a fair distribution of costs between the participants is needed, where individual performance targets exists.   The spare parts suitable for being stocked at a central warehouse are those that are shared by at least two production facilities, are bulky, have a high purchasing value, and are aging quickly.   Using a modified version of the Center of Gravity Method, a centrally located warehouse for the case company’s all Swedish mills has been located to Örebro and the surrounding area. If, however, the central warehouse is only assigned to the case company’s four northernmost mills, the warehouse should according to the modified Center of Gravity Method be located to Ludvika.

Este trabalho é um estudo de caso múltiplo, realizado em concessionárias do setor automotivo, que visa ao levantamento do estado atual da gestão dos estoques de peças de reposição e sua correlação com os modelos existentes na literatura sobre o tema. O estudo englobou sete concessionárias de quatro marcas, apontadas por especialistas das respectivas associações como sendo exemplos de boa gestão neste segmento. Os resultados apontaram que, de fato, no nível gerencial pesquisado existem grandes lacunas entre as teorias acadêmicas e as práticas, em especial quanto ao uso de técnicas de previsão de demanda, à decisão de estocagem dos produtos e às políticas de estocagem adotadas. O principal motivo para explicar estas lacunas é o desconhecimento das técnicas pelos gestores. Este desconhecimento parece estar ligado às deficiências na formação escolar e nos cursos de aperfeiçoamento oferecidos, pelas montadoras e associações, aos gestores destes estoques. Novas pesquisas são sugeridas, ao nível dos proprietários/acionistas das concessionárias, para verificação de outras possíveis explicações sobre os motivos destas lacunas. A pesquisa é concluída com diversas recomendações, tanto aos praticantes como aos acadêmicos, buscando a redução destas lacunas. / This dissertation is a multiple case study, performed in automotive dealers. The objective is to evaluate current spare parts inventory management practices status and their correlations with existing models on academic references. The study included seven dealers (from four different brands) which were recognized as examples of good practices at spare parts management by the dealer association specialists. The results pointed out that, in fact, at the managerial level interviewed, there are large gaps between academic theories and management practice, especially on demand forecasting, stocking decision and stocking policies. The gaps are mainly explained by managers? lack of knowledge on inventory control. This lack of knowledge seems to be caused by school and specialization courses (provided by automakers and dealers associations) deficiencies. New researches are suggested, at the owners/stockholders level, to verify other possible gap reasons. Research is concluded with several recommendations to academics and managers in order to reduce the theory-practice gap.

<p>The wind power industry is maturing and the amount of electricity produced by wind turbines in the world is rapidly increasing every year. Service and maintenance of wind turbines has proven to be difficult and expensive, especially offshore. A well coordinated support organisation and optimized maintenance strategies are required to effectively reduce the costs associated with WT support, where cost-efficient supply and storage of spare parts are important. The aim of this thesis is to model spare part logistics for wind turbines to analyse different strategies and compare the profitability. Optimal stock levels and reorder sizes have been calculated with the software tool OPUS10. Wind turbine and spare part data have been provided by Vattenfall Vindkraft AB and field studies were made to the wind farms Lillgrund and Horns Rev to gather information.</p><p>Our analyses show that different spare part strategies only affect a minor part of the total support costs generated for a wind farm. Still there are many improvements possible and money to be saved if using an optimal spare part strategy instead of one based on personal experiences and intuition. For a large wind power system, including a number of wind farms with the same wind turbine types, we also show convincing results that pooling of spare parts are a much more cost-efficient spare part strategy compared to local storage and handling only. Using a central depot for spare part reordering and storage of critical spare parts, such as gearboxes, generators and blades, are more profitable</p>

The wind power industry is maturing and the amount of electricity produced by wind turbines in the world is rapidly increasing every year. Service and maintenance of wind turbines has proven to be difficult and expensive, especially offshore. A well coordinated support organisation and optimized maintenance strategies are required to effectively reduce the costs associated with WT support, where cost-efficient supply and storage of spare parts are important. The aim of this thesis is to model spare part logistics for wind turbines to analyse different strategies and compare the profitability. Optimal stock levels and reorder sizes have been calculated with the software tool OPUS10. Wind turbine and spare part data have been provided by Vattenfall Vindkraft AB and field studies were made to the wind farms Lillgrund and Horns Rev to gather information. Our analyses show that different spare part strategies only affect a minor part of the total support costs generated for a wind farm. Still there are many improvements possible and money to be saved if using an optimal spare part strategy instead of one based on personal experiences and intuition. For a large wind power system, including a number of wind farms with the same wind turbine types, we also show convincing results that pooling of spare parts are a much more cost-efficient spare part strategy compared to local storage and handling only. Using a central depot for spare part reordering and storage of critical spare parts, such as gearboxes, generators and blades, are more profitable

As a result of global competition, companies within the automotive industry are required to improve their production systems to achieve sustainable and competitive production. To attain operational excellence, companies have adopted concepts like lean and World Class Manufacturing (WCM). In order to deliver, companies need to increase the availability and reliability of production equipment. This demands focus on both operational and strategic maintenance, and efficient equipment acquisition and management. The main objective of this thesis is to identify processes and success factors that are necessary for improved maintenance performance. By conducting a case study and by performing a literature review, the following has been studied: 1) how companies within the automotive industry work with maintenance and maintenance strategies, 2) implementation of maintenance strategies, and 3) new acquisition and spare parts management for maintenance.  The results show that basic maintenance concepts and related terms are well defined in the literature. However, maintenance strategy is not unanimously defined. Results from the case study reveal that Professional Maintenance (PM) within WCM has been considered as a maintenance strategy. Furthermore, driving forces and obstacles for implementing maintenance strategies have been identified. The study also reveals that there is a strong link between maintenance performance, new acquisition and spare parts management. / Den globala konkurrensen inom fordonsindustrin, har medfört krav på företag att effektivisera sina produktionssystem för att åstadkomma en hållbar och konkurrenskraftig produktion. Detta har resulterat i arbete enligt koncept som lean och World Class Manufacturing (WCM).  För att kunna leverera behöver företag öka den tekniska tillgängligheten på utrustning. Detta i sin tur ställer ett ökat krav på både operativt och strategiskt arbete med underhåll, anskaffning och reservdelsstyrning. Målet med examensarbetet är att identifiera processer och faktorer som bidrar till ett förbättrat underhåll. Med hjälp av litteraturstudie och en fallstudie har följande studerats: 1) hur företag inom fordonsindustrin arbetar med underhåll och underhållsstrategier, 2) implementering av underhållsstrategier, och 3) nyanskaffning och reservdelsstyrning för underhåll. Resultat från litteraturstudier visar att det finns en enighet om att underhåll delas in i förebyggande och avhjälpande underhåll. Däremot, visar resultatet att det inte finns en enig definition av underhållsstrategi. Fallstudien visar att Professional Maintenance (PM) inom WCM betraktas som en underhållsstrategi. Som ett resultat har även ett antal drivkrafter och svårigheter som påverkar implementering av underhållsstrategier identifierats. Vidare visar resultatet att det finns ett starkt samband mellan underhåll, nyanskaffning och reservdelsstyrning.