Volvo GTO in Umeå is the largest production unit for cabs of Volvo’s heavy trucks. Currently, the company has three external storage facilities around the Umeå region used for storage of steel coils, pressing tools, and production material. A project regarding the construction of a new logistics center has been initiated, with the aim of combining the current storage facilities into one. This in order to make the logistics flows more efficient, while decreasing costs and emissions. The creation of a new logistics center served as a starting point for this thesis. Emphasis has been placed on determination of optimal inventory levels of steel coils, which is the main component in their production of cabs. The primary aim was to minimize costs while ensuring a sufficient stock available for all coils. To accomplish this, both an optimization model and a simulation model have been developed in order to ascertain optimal order quantities and appropriate safety stock levels based on required service levels. These quantities and safety stocks have later been used to determine the size of the storage area in the logistics center. A significant aspect of this project involved the generation of input data corresponding to demand. Leveraging the resampling technique multivariate moving block bootstrapping on historical demand data from last year has enabled the creation of realistic demand scenarios. The conclusions drawn from the study is that the optimal inventory levels are strongly dependent on anticipated future demand, as evidenced by the different scenarios. Important to state is that the calculations made are based solely on demand variability and not on other crucial factors, such as lead time variability. Future investigations of optimal inventory levels should incorporate additional parameters to obtain a more comprehensive understanding for the management of the inventory system. / Volvo GTO i Umeå är den största produktionsenheten för Volvos hyttproduktion till tunga lastbilar. I dagsläget har Volvo GTO tre externa lagerlokaler i Umeåområdet, som används till lagring av stålcoils, pressverktyg och produktionsmaterial. Ett projekt gällande ett nytt logistikcenter har initierats, som syftar till att slå samman nuvarande lagerlokaler till en. Detta för att skapa mer effektiva logistikflöden, samtidigt som kostnader och utsläpp minskar. Skapandet av ett nytt logistikcenter utgör utgångspunkten för detta projekt. Tyngdpunktenhar legat på att fastställa optimala lagernivåer för stålcoils, vilka utgör huvudkomponenten i Volvos hyttproduktion. Den primära målsättningen var att minimera kostnader och samtidigt säkerställa att tillräckligt med lager finns tillgängligt för samtliga stålcoils. För att uppnå detta skapades både en optimeringsmodell och en simuleringsmodell för att fastställa optimala orderkvantiteter och lämpliga säkerhetslagernivåer, baserat på nödvändiga servicenivåer. Dessa orderkvantiteter och säkerhetslagernivåer användes senare vid bestämning av storleken på lagerytan i logistikcentret. En betydande del av detta arbete utgjordes av generering av indata motsvarande efterfrågan. Nyttjande av återsamplingsmetoden multivariate moving block bootstrapping gjord på historisk data över efterfrågan år 2023 har möjliggjort skapandet av realistiska efterfrågescenarier. Slutsatser som dras från studien är att de optimala lagernivåerna är strikt beroende av den förväntade framtida efterfrågan, vilket visas i de olika scenarierna. Viktigt att poängtera är att beräkningarna gjorda enbart är baserade på variation i efterfrågan och inte på andra avgörande faktorer, såsom variationer i ledtider. Framtida utredningar av optimala lagernivåer bör inkludera ytterligare parametrar för att erhålla en mer övergripande och rättvis förståelse för hanteringen av lagersystemet.

Este trabajo de investigación propone la mejora de gestión de inventarios de la empresa Importaciones y Distribuciones Granados SRL, en donde se identificaron problemas acerca de la rotura de stock de un 33% ocasionando un ingreso no percibido de S/1 012 898,69, tiene un nivel de servicio del 84%, la empresa posee baja rotación de productos, esto simboliza un 33% del dinero paralizado, teniendo un total de ingresos no percibidos de S/1 301 092,45. Se tiene como principal objetivo, mejorar la gestión de inventarios de la empresa Importaciones y Distribuciones Granados SRL para disminuir los ingresos que no son percibidos. Se desarrollo la clasificación ABC a los repuestos y se procedió a calcular indicadores actuales; para la selección del modelo se calcularon los costos de los modelos Q y P, además se realizó una matriz de enfrentamiento para determinar el modelo a utilizar, consecutivamente se halló el modelo de revisión periódica (P), posteriormente se hallaron los indicadores de la mejora; se efectuaron mejoras en los procesos logísticos, se implementaron capacitaciones a los trabajadores, se implementó la metodología 5S y se propuso un sistema ERP, por último se logró calcular el costo-beneficio de todas las propuestas planteadas. Con el resultado obtenido se redujo la rotura de stock a 5%, esto ocasiono que se incremente el nivel de servicio a 95% y se disminuyó el dinero inmovilizado a 2%, por último, se consiguió un beneficio-costo de S/1,42, esto significa que cuando se invierte S/1,00, se logrará un beneficio de S/0,42. / This research work proposes the improvement of inventory management of the company Importaciones y Distribuciones Granados SRL, where problems were identified about the stock out of 33% causing an unperceived income of S / 1 012 898.69, has a service level of 84%, the company has low product turnover, this symbolizes 33% of the paralyzed money, having a total of non-perceived income of S/1,301,092.45. The main objective is to improve the inventory management of the company Importaciones y Distribuciones Granados SRL to reduce the income that is not received. The ABC classification was developed for the spare parts and current indicators were calculated; For the selection of the model, the costs of the Q and P models were calculated, in addition, a confrontation matrix was made to determine the model to be used, consecutively the periodic review model (P) was found, subsequently the indicators of improvement were found. ; Improvements were made in the logistics processes, worker training was implemented, the 5S methodology was implemented and an ERP system was proposed, finally it was possible to calculate the cost-benefit of all the proposals raised. With the result obtained, stock breakage was reduced to 5%, this caused the service level to increase to 95% and the immobilized money was reduced to 2%, finally, a benefit-cost of S / 1 was achieved, 42, this means that when S/1.00 is invested, a profit of S/0.42 will be achieved.

La investigación se desarrolló en la empresa Servicios Generales ADJ EIRL, en la cual se planteó como objetivo mejorar la gestión de inventarios para aumentar los ingresos. En primer lugar, se diagnosticó la gestión de inventario actual de dicha empresa para lo que se empleó la metodología de matriz ABC, se calcularon indicadores de rotura de stock, el nivel del servicio, el costo de mantenimiento y el costo de oportunidad. En segundo lugar, se determinaron las herramientas de ingeniería y metodología para la mejora en la gestión de inventarios, los cuales fueron la aplicación del modelo P, la implementación de un software EGA futura, la capacitación para los colaboradores y la implementación de la 5’S. Finalmente, se realizó un análisis económico de la propuesta donde se determinó que el beneficio de la empresa con la propuesta sería de S/.1,7. Así es como se llegó a la conclusión que, con la propuesta, los ingresos de la empresa aumentarán a S/. 164 289,65; su nivel de servicio se incrementará en un 95% y sus costos disminuirán considerablemente, dando como resultado final que la implementación de la propuesta es viable. / The research was developed at the company Servicios Generales ADJ EIRL, in which the objectives of improving the inventory management of the company to increase revenue were set, as the first objective was to diagnose the current inventory management of the company General services ADJ EIRL where the ABC matrix was made, indicators of stock breakage, service level, maintenance cost and opportunity cost were calculated; The second objective was to determine the engineering tools for the improvement of inventory management in the company Servicios Generales ADJ EIRL, which were the application of the P model, implementation of a future EGA software, training for employees and the implementation of the 5'S; Finally, the last objective was to carry out an economic analysis of the proposal where it was determined that the profit of the company with the proposal would be S / .1.7; thus it was concluded that with the proposal the company will increase its income to S /. 164 289.65; its service level will increase by 95% and its costs

No / This paper presents a stochastic automaton approach to stock ordering for retailers of time-limited goods, in the modern supply chain network. The rationale applied is that by ordering in small quantities frequently, overstocking will be reduced, capital liquidity improved and wastage limited. A consequence for the complete supply chain is that such an approach could substantially minimise the reactive bullwhip effect, leading to more efficient utilisation, production and agility throughout the chain. Such agility and flexibility can only be achieved by full integration of stock inventory monitoring technologies (such as RFID) with enterprise integration systems (such as ERP) connected to suppliers, mediated by the internet. We undertake a comparative simulation study of stock ordering using a stochastic automaton and a naive traditional approach. This shows that stochastic ordering, prompted by a stochastic automaton, exhibits characteristic properties that are a prerequisite for reducing the bullwhip effect, thus enabling agile inventory management.

Studien syftar till att undersöka eventuell optimering av reservdelslagret som Stort AB hanterar åt sin kund. Det har genomförts genom att klassificera artiklarna i reservdelslagret enligt en ABC-klassificering baserat på antal lagerrörelser per artikel. Vidare skapades en optimeringsmodell som prioriterar artikelplacering utifrån ABC-klassificeringen. Optimeringsmodellen löstes med hjälp av linjärprogrammering i programvaran LINGO 20.0 med den objektiva funktionen att minimera avståndet artiklarna rör sig i reservdelslagret. Resultatet av optimeringen presenteras i en zonindelad skiss av reservdelslagret baserat på ABC-klassificeringen. För att bekräfta att resultatet från optimeringen faktiskt optimerade reservdelslagret så jämfördes det optimerade avståndet med nuvarande avstånd som artiklarna rör sig. Modellen är indelad i två höjdnivåer där nivå ett går att plocka för hand och nivå två kräver truckkörning. Det försvårar beräkningen för hur mycket modellen optimerade reservdelslagret eftersom det var svårt att jämföra tiden (avståndet) det tar att plocka för hand med tiden (avståndet) det tar att plocka med truck. Problemet löstes genom att göra ett intervall som varierar tiden (avståndet) det tar att plocka en artikel med truck. Studien resulterade i att reservdelslagret optimerades genom att avståndet minimerades i jämförelse med den befintliga artikelplaceringen. / The purpose of this study is to evaluate eventual optimization of the spare part warehouse that Stort AB manages for its customer. This has been carried out by classifying the products in the spare parts warehouse according to an ABC-classification based on the warehouse movement frequency of each product. Thereafter an optimization model was created that prioritizes the product placement according to the classification. The optimization model was solved by using linear programming in the software LINGO 20.0 with the objective function to minimize distance that the products move in the spare part warehouse. The result of the optimization is presented in a zoned sketch of the spare parts warehouse based on the ABC-classification. In order to verify that the optimization actually optimized the spare parts warehouse, the total optimized travel distance of the products was compared to the current total travel distance of the products. The optimization model is divided into two different height levels where a forklift is required for the highest level. This poses trouble for calculating the degree of optimization that the model provides since it is hard to compare the time (distance) it takes to pick a product by hand and the time (distance) it takes to pick a product with a forklift. A workaround for that problem is to calculate the degree of optimization on an interval that varies the time (distance) it takes to pick a product with a forklift. This study resulted in an optimization by reducing the distance traveled in the warehouse compared to the current product placement.

Snabbmatsrestauranger har svårt att hålla en bra lagerstyrning på grund av föråldrade inventeringsmetoder. Där manuell inventering sker varje dag för att kontrollera vad som finns i lager. Detta är en tidskrävande process som kräver arbetskraft att utföra. Det uppstår ofta fel i lagersaldo på grund av manuell kontroll, då det handlar om många varor på en liten yta och med en hög lageromsättningshastighet. I andra lagermiljöer används vägning som inventeringsmetod för att underlätta lagerstyrningen. Syftet med denna studie är att undersöka om vägningen är en lämplig metod för att kontrollera lagersaldo i små manuella lager med hög omsättningshastighet hos snabbmatsrestauranger. En empirisk studie genomfördes i form av semistrukturerade intervjuer. Två snabbmatsrestauranger var inblandade, där fyra personer intervjuades, alla respondenterna jobbade inom forskningsområdets specifika lagermiljö och har hand om lagerstyrningen för dessa lager. Två forskningsfrågor besvarades utifrån intervjuerna, vilket bidrog till att uppfylla syftet med studien. En innehållsanalys utfördes på den empiriska datan som samlades in från intervjuerna, för att underlätta bearbetningen av datan och få ut information som kan besvara forskningsfrågorna och syftet med studien. Tidigare forskning visar att vägning är en användbar metod för att kontrollera lagersaldo. Den empiriska studien gav en bättre uppfattning om tekniken skulle kunna användas i små manuella lager med hög omsättningshastighet hos snabbmatsrestauranger. Där svarade respondenterna att denna lagermiljö inte är anpassad för att kunna införa ett fungerande vägningssystem som kan ge ett korrekt lagersaldo. Då det finns många hinder som kan uppstå med att implementera ett fungerande vägningssystem. Ett hinder är att det förvaras många olika artiklar i lagret på en liten yta, vilket leder till problem vid vägningen av varorna. Att det skulle vara svårt att kunna urskilja alla olika artiklar och få ett korrekt vägningsresultat. Ur intervjuerna kom det även fram att förvaring av artiklarna i lagren inte förvaras likadant, vissa produkter staplas på backvagnar, en del förvaras på hyllor medan vissa artiklar är staplade på varandra från marknivå. Vilket försvårar användningen av ett vägningssystem. Under höga försäljningsperioder kan det bli problematiskt med ett vägningssystem, då det kan krävas att artiklar lagras i andra utrymmen än i lagren. Vilket gör ett sådant system irrelevant om den inte kan väga alla artiklar och ge ett korrekt lagersaldo. / Today, fast food restaurants find it difficult to maintain good inventory management due to outdated inventory methods. Where manual inventory takes place every day to check what is in stock. This is a time-consuming process that requires manpower to perform. There are often errors in the stock balance due to manual control, as it involves many goods in a small area and with a high stock turnover rate. In other warehouse environments, weighing is used as an inventory method to facilitate inventory control. The purpose of this study is to investigate whether weighing is a suitable method for controlling inventory balance in small manual warehouses with high turnover rates in the fast foodindustry. An empirical study was conducted in the form of semi-structured interviews. Two fast food restaurants were involved, where four people were interviewed and all the respondents worked within the specific warehouse environment of the research area and are in charge of inventory control for these warehouses. Two research questions were answered based on the interviews, which contributed to fulfilling the purpose of the study. A content analysis was performed on the empirical data collected from the interviews. To facilitate the processing of the data and obtain information that can answer the research questions and the purpose of the study. Previous research shows that weighing is a useful method of controlling inventory balance. The empirical study gave a better idea of whether the technology could be used in small manual warehouses with a high turnover rate. There, the respondents answered that this warehouse environment is not necessarily adapted to be able to introduce a functioning weighing system that can provide an accurate inventory balance. As there are many obstacles that can arise in implementing a functioning weighing system. An obstacle is that many different articles are stored in the warehouse on a small surface, which leads to problems when weighing the goods. That it would be difficult to distinguish all the different articles and get a correct weighing result. The interviews also revealed that the storage of the articles in the warehouses is not the same, some products are stacked on back carts, some are stored on shelves while some articles are stacked on top of each other from ground level. Which complicates the use of a weighing system. During high sales periods, it can become problematic with a weighing system in the warehouse as it may sometimes be required that items be stored in areas other than the warehouses. Which makes such a system irrelevant if it cannot weigh all items and provide an accurate inventory balance.

La presente investigación tuvo como objetivo general proponer una mejora de gestión de inventarios para reducir los ingresos no percibidos en la Vidriería Michel en el año 2022. El tipo de investigación es aplicada, de nivel descriptiva, el propósito del diseño de esta investigación es cuantitativo y es no experimental. Se obtuvo como resultados un ingreso no percibido del 24,1%, por quiebres de stock, sobre stock de productos, productos dañados y la inexactitud de inventarios. Para lo cual se propuso el modelo P de inventario, siendo el de revisión periódica, procedimientos estandarizados de la gestión de inventarios, implementación de la metodología 5s, programa de capacitaciones a los trabajadores, la implementación de un ERP y la redistribución del layout. Al realizar un análisis costo beneficio de la propuesta de mejora de la gestión de inventarios obtuvo un VAN de 82 735,39 soles, un TIR de 52,64%, un Beneficio-Costo de 1,47 y una tasa de recuperación de 1 año, 6 meses y 24 días, determinando la viabilidad económica de la propuesta. / The general objective of this research was to propose an improvement in inventory management to reduce the income not received at Vidriería Michel in 2022. The type of research is applied, descriptive level, the purpose of the design of this research is quantitative and non-experimental. The results were a non-perceived income of 24,1%, due to stock shortages, overstock of products, damaged products, and inventory inaccuracy. For which the inventory model P was proposed, being that of periodic review, standardized inventory management procedures, implementation of the 5s methodology, a training program for workers, the implementation of an ERP and the redistribution of the design. When conducting a cost-benefit analysis of the proposal to improve inventory management, a NPV of 82 735,39 soles was obtained, an IRR of 52,64%, a Benefit-Cost of 1,47 and a recovery rate of 1 year, 6 months and 24 days, determining the economic viability of the proposal.

En el presente trabajo de investigación se ejecutó en la empresa de compra y venta de materiales de construcción, se identificó la problemática de disminución de las ventas. Asimismo, como objetivo principal se planteó el proponer la mejora de la gestión de inventarios para aumentar las ventas. Para ello, se diagnosticó que la problemática es a causa de la pérdida de oportunidad de ventas con un 12,61%, por la cantidad de unidades de materiales deterioradas del 2,62%, por otro lado, el bajo nivel de servicio de 85,36%, teniéndose una planificación empírica de requerimiento de materiales, presencia de rotura de stock y el deterioro de materiales, la falta de organización y orden en el almacén, y la falta de capacitación laboral. Por consiguiente, se elaboró la propuesta de mejora, en la que se aplicó el modelo de revisión periódica (P), políticas de inventarios, mejora de los procesos logísticos, manual de procedimientos en el almacén y plan de capacitación al personal sobre temas logísticos, disminuyendo los pedidos no atendidos por deterioro de materiales a 0,86%; además, redujo las pérdidas de oportunidad de ventas a un 8,90 % y aumentó el nivel de servicio al 95% y las ventas en S/ 16 083,36. Finalmente, se evaluó el costo – beneficio de la mejora propuesta obteniendo un beneficio de S/ 11 563,53, donde la relación beneficio/costo es de S/ 1,90; es decir, que / In the present research work was carried out in the company of purchase and sale of construction materials, the problem of decrease in sales was identified. Likewise, the main objective was to propose the improvement of inventory management to increase sales. To do this, it was diagnosed that the problem is due to the loss of sales opportunity with 12.61%, due to the number of units of deteriorated materials of 2.62%, on the other hand, the low level of service of 85.36%, having an empirical planning of material requirement, presence of stock breakage and deterioration of materials, the lack of organization and order in the warehouse, and the lack of job training. Therefore, the improvement proposal was elaborated, in which the periodic review model (P), inventory policies, improvement of logistics processes, manual of procedures in the warehouse and training plan for personnel on logistics issues were applied, reducing the orders not attended by deterioration of materials to 0.86%; in addition, it reduced sales opportunity losses to 8.90% and increased the service level to 95% and sales by S/ 16 083.36. Finally, the cost-benefit of the proposed improvement was evaluated, obtaining a benefit of S/ 11 563.53, where the benefit/cost ratio is S/ 1.90; that is, for every S/ 1.00 that the company invests in the project, there will be a profit of S/ 0.90.

Según los datos obtenidos por el INEI al año 2017, existen 3 millones 51 mil 612 personas que tienen algún tipo de discapacidad y dentro de ellas se encuentran las personas afectadas por accidentes cerebro vasculares. De acuerdo al último Censo Nacional, esta cifra representa el 10.4% del total de la población del país para ello el cuidado de una persona afectada por un accidente cerebrovascular causa un estrés debido a la carga física y psicológica; por lo tanto, para contribuir con la actividad de aseo personal de pacientes con grado de dependencia IV, se diseñó una máquina confortable mediante el método de marco de referencia lógico que abarca diferentes aspectos evaluados como: clasificación de objetivos, establecimiento de funciones, fijación de requerimientos, determinación de características, generación de alternativas y evaluación de alternativas de solución. En síntesis, se obtuvo el diseño de la máquina confortable mediante el análisis estructural en el software SolidWorks obteniendo valores del límite elástico, del esfuerzo de desplazamiento, la deformación unitaria y el factor de seguridad. / According to the data obtained by the INEI in 2017, there are 3 million 51 thousand 612 people who have some type of disability and among them are people affected by cerebrovascular accidents. According to the last National Census, this figure represents 10.4% of the total population of the country. For this, the care of a person affected by a cerebrovascular accident causes stress due to the physical and psychological load; therefore, to contribute to the personal hygiene activity of patients with degree of dependency IV, a comfortable machine was proposed using the logical reference framework method that covers different aspects evaluated such as: objective classification, establishment of functions, fixation of requirements, determination of characteristics, generation of alternatives and evaluation of solution alternatives. In summary, the design of the comfortable machine was obtained through the structural analysis in the SolidWorks software, obtaining the elastic limit, the displacement effort, the unitary deformation and the safety factor.

El trabajo de investigación se enfocó en rediseñar la gestión de inventarios en una Estación de Servicios. El análisis reveló que la empresa pierde un monto de 74 336,88 soles, los cuales son originados rincipalmente por la falta de capacitación al personal de la empresa, dispensadores en mal estado, falta de instrumentos de medición precisos para medir inventarios y la falta de un sistema de gestión de inventarios. Para abordar estos desafíos, se propuso la implementación de un modelo de gestión de inventarios basado en el cálculo de inventarios de seguridad, puntos de reorden, junto con mejoras en los procesos logísticos, capacitación del personal y la adquisición de un sistema de medición por telemetría. La evaluación económica respaldó la viabilidad de estas mejoras, al mostrar un Valor Actual Neto (VAN) a 5 años de 64 278,89 soles, una Tasa Interna de Retorno (TIR) del 111,3%, un Beneficio Costo de 1,65 soles y un período de recuperación de 255 días. En resumen, esta investigación identificó desafíos, ofreció soluciones efectivas y generó resultados positivos en la gestión de inventarios que tuvieron un impacto directo en la disminución de las ventas no percibidas. / The research work focused on redesigning inventory management in a Service Station. The analysis revealed that the company loses an amount of 74 336,88 soles, which are mainly caused by the lack of training for the company's personnel, dispensers in poor condition, lack of precise measuring instruments to measure inventories and the lack of an inventory management system. To address these challenges, the implementation of an inventory management model based on the calculation of safety inventories, reorder points, along with improvements in logistics processes, staff training and the acquisition of a telemetry measurement system was proposed. The economic evaluation supported the viability of these improvements, showing a 5-year Net Present Value (NPV) of 64 278,89 soles, an Internal Rate of Return (IRR) of 111,3%, a Cost Benefit of 1,65 soles and a recovery period of 255 days. In summary, this research identified challenges, offered effective solutions, and generated positive inventory management results that had a direct impact on decreasing lost sales.