Background Companies which operate within heavy equipment are highly dependent on a continuous spare part stream to minimise their production downtime. The disruption of the pandemic known as Covid19 has brought the global supply chain to its knee, and countless companies have been affected by the global supply shortage. One of such industries is heavy equipment which comprises heavy-duty vehicles, large equipment, large-scale infrastructure, intricate or numerous processes with high operation cost and a unique set of challenges. Consequently, the demand for spare parts within heavy equipment can be extremely unpredictable and erratic, since the life cycle of machinery is connected to systems owned by the customers and its applications. Therefore, understanding the heavy equipment industry could allow for new innovative ways for managing spare part challenges. One of the methods for solving spare part challenges in other industries according to previous research has been the utilisation of additive manufacturing (AM).The AM technology is based on incremental layer-by-layer manufacturing compared to conventional manufacturing (CM) which mostly depend on subtractive manufacturing processes. Research questions RQ1: What are the challenges within the heavy equipment industry regarding spare part management? RQ2: How can the heavy equipment industry utilise additive manufacturing to overcome challenges surrounding spare parts management? Method The literature review comprised of the identification of spare part management challenges surrounding heavy equipment, the capabilities of AM surrounding spare parts as well as optimisation methods for existing parts with AM. Whereas the interviews consisted of two sets of interview groups (i.e., heavy equipment and AM based companies). Lastly, the experiment consisted of validating gathered data as well as identifying AMs capabilities based on a physical object (i.e., lifting bracket). Findings The findings show the existing spare part management challenges within heavy equipment are related to four dimensions namely: warehousing, cost, lead times and the environment.Whereas the findings surrounding AMs capabilities for mitigating spare part management challenges showed that, AM enable the production of low volume parts with low lead time replenishment. This could minimise overall waste within the heavy equipment industry, where central warehousing could be reduced as well as the total lead time for customers.

Denna studie är en kvantitativ studie som syftar till att undersöka sambandet mellan tillgängligheten av reservdelar och maskinprestanda. Litografi och plasma är Silexs två produktionsstationer som undersöks i denna studie. Det analyseras data över en tre månaders period för att undersöka sambandet mellan reservdelskostnader och maskinernas drifttid. Metoden innefattar en kvantitativ analys av reservdelslager, maskinprestanda och rapporterade maskintillstånd. Statistiska verktyg används för att identifiera korrelationer. Resultaten visade att det finns en koppling mellan tillgängligheten av reservdelar och deras förbrukning, eftersom de maskiner som hade flest reservdelar på lager också gjorde flest uttag av reservdelar under underhåll. I Litografi fanns det en komplex korrelation: vissa maskiner visade en negativ korrelation mellan kostnad och prestanda eftersom de inte hade tillräckligt med reservdelar på lagret, medan andra maskiner visade en positiv korrelation, vilket tyder på att tillgängliga reservdelar förkortade drifttiden. Plasma-arean visade en positiv korrelation mellan reservdelskostnader och drifttid. Trots detta uppstod begränsningar för kapitalbindning och lagerutrymme som ett resultat av en överrepresentation av långsamtgående reservdelar i lagret. Slutsatsen är att det finns ett samband mellan maskinprestanda och tillgången på reservdelar, och att en balanserad tillgång till kritiska reservdelar är avgörande för att optimera driften. Förbättringar som skulle kunna göras inkluderar att standardisera rapporteringstekniker, skapa ett säkerhetslager för varje maskin. För att analysera slow-mover-reservdelar och göra en ekonomisk jämförelse mellan SLA-täckta och lagerreservdelar krävs ytterligare forskning. / This study is a quantitative analysis that aims to explore the link between spare parts availability and machine performance. The two production lines examined in this study are lithography and plasma at Silex. Data spanning a three-month period is analyzed to examine the correlation between spare parts costs and machine uptime. The methodology involves a quantitative analysis of spare parts stocks, machine performance, and reported machine conditions. Statistical tools are used to identify correlations. The results showed a correlation between spare parts availability and consumption, as machines with the highest spare parts stocks also made the most withdrawals during maintenance. In lithography, a complex correlation was observed: some machines showed a negative correlation between spareparts cost and machine performance due to insufficient spare parts stock, while others showed a positive correlation, suggesting that available spare parts shortened downtime. The plasma area showed a positive correlation between spare parts costs and uptime. However, limitations arose in terms of capital tied up and storage space due to an over-representation of slow-moving spare parts in the stock. The conclusion indicates a correlation between machine performance and the availability of spare parts, emphasizing that a balanced supply of critical spare parts is essential for optimizing operations. Suggested improvements include standardizing reporting techniques and creating a safety stock for each machine. Further research is needed to analyze slow-moving spare parts and make an economic comparison between SLA-covered and stock spare parts.

The clinical efficacy of adoptive T cell therapies including CAR T therapy are limited by poor in vivo persistence and moderate anti-tumor efficacy. According to the literature, metabolism plays a critical role in the phenotypic state and fate of T cells during antigen-driven expansion. During different stages of a T cell life cycle, the predominant pathway used for metabolism changes. Naïve T rely on oxidative phosphorylation, but as the T cells becomes activated, their metabolic profile switches to become more reliant on glycolysis. Most T cells become terminally differentiated and become senescent once they have performed their cytotoxic function. A minority of the activated T cells gradually start to rely on oxidative phosphorylation once again and become memory T cells. Memory T cells can become either effector memory or central memory T cells. These memory T cells, specifically central memory T cells, are the key to T cells persistence during both ex vivo and in vivo expansion and following disappearance of the antigenic stimulus. Since the metabolic profile of the T cells plays a critical role in its differentiation state, we tested the hypothesis that inhibitors of intermediary metabolism could promote a metabolic profile that is more desirable for the optimal phenotype consistent with the memory phenotype that would favor persistence in spite of strong activation signals. The four inhibitors screened were: a PFKFB3 inhibitor, an inhibitor of a key step in glycolysis; ibrutinib, an inhibitor of Bruton’s tyrosine kinase; idelalisib, an inhibitor of PI3K subunit; and duvelisib, an inhibitor of PI3K and PI3K gamma subunits. To test this hypothesis, T cells were cultured with or without each compound and then the analysis included: phenotypic analysis by flow cytometry, quantitative analysis by counting cells with ethidium bromide acridine orange, and metabolic profiling by the Seahorse assay. This study was conducted using T cells from a human healthy volunteer that were collected by apheresis. T cells were cultured in a G-Rex plate for 15 days with complete media supplemented with recombinant human IL-2 (30 U/mL). Cells were activated on day 1 and day 8 by the addition of anti-CD3/CD28 beads and test metabolic inhibitor compounds were added every 4 days. T cells cultured with idelalisib, duvelisib, and ibrutinib had increased expansion (approximately50-fold: idelalisib/ duvelisib and 21-fold ibrutinib) when compared to control (cells with beads alone) with only 6-fold expansion. Phenotypic analysis performed using flow cytometry showed an increased percentage of CD27+ CD28+ in the CD8+ and CD4+ T cell cell populations in the idelalisib treated group and decreased number of senescent T cells that are double negative for CD27 and CD28. Consistent with our hypothesis, metabolic analysis showed that cells treated with idelalisib and duvelisib were more reliant on oxidative phosphorylation, rather than glycolysis as compared to the control cultures. Cells treated with duvelisib also showed an increased spare respiratory capacity (SRC), which is associated with more efficacious memory T cells. The results of these studies show that metabolism plays a critical role in the long-term survival of T cells. We demonstrate that inhibiting intermediary metabolism, specifically inhibiting PI3K, favorably alters the metabolic state of the T cells leading to increased cell numbers and T cells with a phenotype consistent with enhanced ex vivo and in vivo proliferation and persistence.

Em diversos setores, em especial no automotivo, uma boa gestão dos estoques de peças de reposição tem impacto significativo na satisfação dos clientes e em sua fidelidade aos fabricantes. Neste trabalho foram estudadas diferentes políticas de gestão dos estoques de peças de reposição, para comparar seu desempenho e elaborar recomendações para seu uso. Foram comparados 17 conjuntos de políticas que envolvem diferentes abordagens no registro das demandas (dados individuais de cada pedido versus dados agregados em janelas de tempo semanais e mensais), modelos de previsão (média móvel, Croston modificado SBA) e diferentes formas de modelar a distribuição da demanda durante o Lead-time de ressuprimento (Normal, Gama, Binomial Negativa, composta Poisson-Normal, composta Poisson-Gama). Cada um desses 17 conjuntos de políticas foi simulado sob duas dinâmicas de reparametrização (mensal e semestral) e para quatro objetivos diferentes do nível de serviço (TFR: Target Fill Rate), totalizando 136 simulações para cada item do estoque (SKU). Foram considerados 10.032 SKU\'s de uma montadora de automóveis instalada no Brasil, com um histórico de seis anos de movimentação. Diferentes recomendações foram elaboradas conforme categorização dos itens já existente na literatura. Os resultados apontaram recomendações distintas para cada TFR, incluindo combinações de todas as alternativas estudadas, descartando apenas o uso das distribuições Normal, composta Poisson-Normal e composta Poisson-Gama. Sugere-se que as recomendações sirvam como guia para o uso desses modelos pelos praticantes. / In many areas, including automotive, a good spare parts inventory management can substantially affect customer satisfaction and their loyalty to the brands. Different spare parts inventory control policies were evaluated in this study, aiming to compare their performance and write recommendations for their usage. Seventeen policy sets were compared, including different approaches in recording demand data (individual orders data against time bucket records weekly and monthly), different demand forecasting methods (simple moving average, Syntetos-Boylan-approximation SBA) and different models for demand distribution during lead-time (Normal, Gama, Negative Binomial, compound Poisson-Normal, compound Poisson-Gama). Each policy set was simulated under two revision frequencies (monthly and semi-annually) and four different Target-Fill-Rates (TFR), totalizing 136 simulation runs for each SKU. Database included movement of 10.032 SKU´s during last 6 years from an automaker installed in Brazil. Results pointed different recommendations for existing classification schemes and under each TFR. Recommendations included all studied alternatives, discarding only the usage of Normal, compound Poisson-Normal and compound Poisson-Gama for demand distribution during lead-time. Practitioners are stimulated to use these recommendations as a guideline.

Em diversos setores, em especial no automotivo, uma boa gestão dos estoques de peças de reposição tem impacto significativo na satisfação dos clientes e em sua fidelidade aos fabricantes. Neste trabalho foram estudadas diferentes políticas de gestão dos estoques de peças de reposição, para comparar seu desempenho e elaborar recomendações para seu uso. Foram comparados 17 conjuntos de políticas que envolvem diferentes abordagens no registro das demandas (dados individuais de cada pedido versus dados agregados em janelas de tempo semanais e mensais), modelos de previsão (média móvel, Croston modificado SBA) e diferentes formas de modelar a distribuição da demanda durante o Lead-time de ressuprimento (Normal, Gama, Binomial Negativa, composta Poisson-Normal, composta Poisson-Gama). Cada um desses 17 conjuntos de políticas foi simulado sob duas dinâmicas de reparametrização (mensal e semestral) e para quatro objetivos diferentes do nível de serviço (TFR: Target Fill Rate), totalizando 136 simulações para cada item do estoque (SKU). Foram considerados 10.032 SKU\'s de uma montadora de automóveis instalada no Brasil, com um histórico de seis anos de movimentação. Diferentes recomendações foram elaboradas conforme categorização dos itens já existente na literatura. Os resultados apontaram recomendações distintas para cada TFR, incluindo combinações de todas as alternativas estudadas, descartando apenas o uso das distribuições Normal, composta Poisson-Normal e composta Poisson-Gama. Sugere-se que as recomendações sirvam como guia para o uso desses modelos pelos praticantes. / In many areas, including automotive, a good spare parts inventory management can substantially affect customer satisfaction and their loyalty to the brands. Different spare parts inventory control policies were evaluated in this study, aiming to compare their performance and write recommendations for their usage. Seventeen policy sets were compared, including different approaches in recording demand data (individual orders data against time bucket records weekly and monthly), different demand forecasting methods (simple moving average, Syntetos-Boylan-approximation SBA) and different models for demand distribution during lead-time (Normal, Gama, Negative Binomial, compound Poisson-Normal, compound Poisson-Gama). Each policy set was simulated under two revision frequencies (monthly and semi-annually) and four different Target-Fill-Rates (TFR), totalizing 136 simulation runs for each SKU. Database included movement of 10.032 SKU´s during last 6 years from an automaker installed in Brazil. Results pointed different recommendations for existing classification schemes and under each TFR. Recommendations included all studied alternatives, discarding only the usage of Normal, compound Poisson-Normal and compound Poisson-Gama for demand distribution during lead-time. Practitioners are stimulated to use these recommendations as a guideline.

Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.

<p>This paper analyses the pricing on spare parts. Empirical studies have showed that manufacturers of durable goods make an unproportional large profit on its spare parts in relation to the revenue it generates. It is first showed that according to the standard economic model the price on spare part ought to be zero since the producer include an insurance in the price of the main good. Further it is showed that moral hazard alone do not explain the pricing found in the studies. Finally an analysis of whether consumers with present-biased preferences could be a possible explanation is made. The analysis finds that it is a possibility however somewhat unlikely.</p>

This paper analyses the pricing on spare parts. Empirical studies have showed that manufacturers of durable goods make an unproportional large profit on its spare parts in relation to the revenue it generates. It is first showed that according to the standard economic model the price on spare part ought to be zero since the producer include an insurance in the price of the main good. Further it is showed that moral hazard alone do not explain the pricing found in the studies. Finally an analysis of whether consumers with present-biased preferences could be a possible explanation is made. The analysis finds that it is a possibility however somewhat unlikely.

Didelę reikšmę paauglystėje turi laisvalaikis, nes tinkamai organizuotas užimtumas taip pat gali padėti išvengti daugelio problemų. Viena iš jų, paauglių šeimų materialinė padėtis dažnai lemia laisvalaikio pasirinkimo galimybę. Į sociokultūrinių institucijų teikiančių laisvalaikio paslaugas patenka ne visi norintys paaugliai. Svarbus vaidmuo plėtojant neformalųjį vaikų švietimą ir užimtumą tenka atsakingoms valstybės ir savivaldybės institucijoms. Jų kuriama ir vykdoma politika turėtų būti grindžiama glaudaus bendradarbiavimo tarp valstybės ir savivaldybės įstaigų, bendruomenių ir nevyriausybinių organizacijų principu. Būtina, kad šiame bendradarbiavime aktyviai dalyvautų ir savo pozicijas gintų jaunimo, tėvų ir kitų neformaliuoju švietimu besirūpinančių pilietinių organizacijų atstovai. Todėl, atsižvelgiant į šios problemos aktualumą ir norint ją ištirti, tyrimo objektu pasirinktas Vilniaus miesto Karoliniškių mikrorajono teikiamų laisvalaikio paslaugų sociokultūrinėse institucijose efektyvumas. Tyrimo tikslas – nustatyti Karoliniškių mikrorajono sociokultūrinių institucijų laisvalaikio teikiamų paslaugų paaugliams efektyvumą. Tyrimo uždaviniai: 1. apibūdinti Vilniaus miesto Karoliniškių mikrorajono sociokultūrinių institucijų ir mokyklų paauglių papildomojo ugdymo veiklos kokybę; 2. išsiaiškinti ar pakankamai Vilniaus miesto Karoliniškių mikrorajone sociokultūrinių institucijų teikiančių paaugliams organizuoto laisvalaikio paslaugas; 3. išanalizuoti kaip paauglius savo... [toliau žr. visą tekstą] / Leisure takes a significant part in adolescence since properly organized employment can also solve many problems. On of them are circumstances of teenager, s family, which determines the choice of leisure activities. Not all the willing teenagers are fortuned to get leisure services by sociocultural institutions. Responsible for that and municipality institutions take the main role in developing unofficial education for children and for their occupation too. Their established and implemented policy should be based on close cooperation between state and municipality institutions, communities and not governmental institutions. It, s essential for representatives of civil institutions caring about informal education and also for young people and parents to participate and advocate their attitudes while cooperating. Therefore, considering the significance of this problem and in order to tackle it the subject of research is efficiency of leisure services provided by sociocultural institutions of the district of Karoliniskes of city of Vilnius. Analysis objective – to rate the efficiency of leisure services for teenagers provided by sociocultural institutions of the district of Karoliniskes. Goals of analysis: 1. To characterize the quality of activity for additional training for teenagers of schools and sociocultural institutions of the district of Karoliniskes in Vilnius; 2. To ascertain if there are enough sociocultural institutions in the district of Karoliniskes that... [to full text]

Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.