Daily drayage operations involve moving loaded or empty equipment between customer locations and rail ramps. Drayage orders are generally pickup and delivery requests with time windows. The repositioning of empty equipment may also be required in order to facilitate loaded movements. The drayage orders are satisfied by a heterogeneous fleet of drivers. Driver routes must satisfy various operational constraints. In the first part of the dissertation, our goal is to minimize the cost of daily drayage operations in a region on a given day. We present an optimization methodology for finding cost-effective schedules for regional daily drayage operations. The core of the formulation is a set partitioning model whose columns represent routes. Routes are added to the formulation by column generation. We present numerical results for real-world data which demonstrate that our methodology produces low cost solutions in a reasonably short time. The second part of the dissertation addresses minimizing total empty mileage when driver capacity is not restrictive and new orders are added to the problem in an online fashion. We present a lower bound for the worst case guarantee of any deterministic online algorithm. We develop a solution methodology and provide results for the performance of different scheduling policies and parameters in a simulated environment. In the third part of the dissertation, we study a system with one rail ramp and one customer location which is served by a single driver. The problem has discrete time periods and at most one new order is released randomly each time period. The objective is to maximize the expected number of orders covered. With this simple problem, we seek to learn more about route planning for a single driver under uncertainty. We prove that carrying out an order ready to be picked up at the driver's current location is optimal for the case with one customer location. We show that the structure of the optimal policies is not simple and depends on various parameters. We devise a simple policy which yields provably near-optimal results and identify a case for which that policy is optimal.

Um dos problemas mais relevantes em organizações de grande porte é a escolha de locais para instalação de plantas industriais, centros de distribuição ou mesmo pontos comerciais. Esse problema logístico é uma decisão estratégica que pode causar um impacto significativo no custo total do produto comercializado. Existem na literatura diversos trabalhos que abordam esse problema. Assim, o objetivo desse trabalho é analisar o problema da localização de instalações proposto por diferentes autores e definir um modelo que seja o mais adequado possível ao mercado de distribuição de combustíveis no Brasil. Para isso, foi realizada uma análise do fluxo de refino e distribuição praticado neste segmento e da formação do respectivo custo de transporte. Foram consideradas restrições como capacidade de estoque, gama de produtos ofertados e níveis da hierarquia de distribuição. A partir dessa análise, foi definido um modelo matemático aplicado à redução dos custos de frete considerando-se a carga tributária. O modelo matemático foi implementado, em linguagem C, e permite simular o problema. Foram aplicadas técnicas de computação paralela visando reduzir o tempo de execução do algoritmo. Os resultados obtidos com o modelo Single Uncapacited Facility Location Problem (SUFLP) simulado nas duas versões do programa, sequencial e paralela, demonstram ganhos de até 5% em economia de custos e redução do tempo de execução em mais de 50%. / One of the most relevant problems at large organizations is the choice of locations for estabilishing facilities, distribution centers or retail stores. This logistics issue is an strategic decision which may cause signicant impact at the eective cost of the product. There are several papers tackling this issue. The objective of this dissertation is to analyze the Facility Location Problem previously developed by other authors and to dene the most applicable model to the fuel distribution industry in Brazil. It started from the analyzis of the upstream and downstream ow in practice at this segment and from the respective transportation cost formation. Some constraints were considered like stock capacity, multicommodity oer and distribution hierarchy levels so it could be possible to dene a mathematical model applied to freight economy considering the incident taxes. The dissertation also has the objective of creating a program using the C language which could simulate the problem. It were applied parallel computing techniques to reduce runtime of the algorithm. The results obtained from the Single Uncapacited Facility Location Problem (SUFLP) executed in both program versions, sequential and parallel, demonstrate up to 5% of eective costs gain and reduction of more than 50% in execution time.

Um dos problemas mais relevantes em organizações de grande porte é a escolha de locais para instalação de plantas industriais, centros de distribuição ou mesmo pontos comerciais. Esse problema logístico é uma decisão estratégica que pode causar um impacto significativo no custo total do produto comercializado. Existem na literatura diversos trabalhos que abordam esse problema. Assim, o objetivo desse trabalho é analisar o problema da localização de instalações proposto por diferentes autores e definir um modelo que seja o mais adequado possível ao mercado de distribuição de combustíveis no Brasil. Para isso, foi realizada uma análise do fluxo de refino e distribuição praticado neste segmento e da formação do respectivo custo de transporte. Foram consideradas restrições como capacidade de estoque, gama de produtos ofertados e níveis da hierarquia de distribuição. A partir dessa análise, foi definido um modelo matemático aplicado à redução dos custos de frete considerando-se a carga tributária. O modelo matemático foi implementado, em linguagem C, e permite simular o problema. Foram aplicadas técnicas de computação paralela visando reduzir o tempo de execução do algoritmo. Os resultados obtidos com o modelo Single Uncapacited Facility Location Problem (SUFLP) simulado nas duas versões do programa, sequencial e paralela, demonstram ganhos de até 5% em economia de custos e redução do tempo de execução em mais de 50%. / One of the most relevant problems at large organizations is the choice of locations for estabilishing facilities, distribution centers or retail stores. This logistics issue is an strategic decision which may cause signicant impact at the eective cost of the product. There are several papers tackling this issue. The objective of this dissertation is to analyze the Facility Location Problem previously developed by other authors and to dene the most applicable model to the fuel distribution industry in Brazil. It started from the analyzis of the upstream and downstream ow in practice at this segment and from the respective transportation cost formation. Some constraints were considered like stock capacity, multicommodity oer and distribution hierarchy levels so it could be possible to dene a mathematical model applied to freight economy considering the incident taxes. The dissertation also has the objective of creating a program using the C language which could simulate the problem. It were applied parallel computing techniques to reduce runtime of the algorithm. The results obtained from the Single Uncapacited Facility Location Problem (SUFLP) executed in both program versions, sequential and parallel, demonstrate up to 5% of eective costs gain and reduction of more than 50% in execution time.

Bakgrund – Essity, en framstående aktör inom hygien- och hälsobranschen, står inför utmaningar gällande logistikflödet för konsumentprodukter från produktionsanläggningen i Lilla Edet till kunder i Danmark. Den nuvarande logistikprocessen involverar intern transport med egna lastbilar till externa lager. I detta sammanhang är det av yttersta vikt att säkerställa snabba och kostnadseffektiva leveranser, samtidigt som kundtillfredsställelse upprätthålls. Syfte – Projektet syftar till att analysera och optimera Essitys nuvarande logistikflöde för konsumentprodukter. Fokus ligger på att identifiera potentiella förbättringar för att säkerställa smidiga och effektiva leveranser till den danska marknaden. En central del av studien innefattar även övervägandet av att integrera en tredjepartslogistikpartner (3PL) för att ytterligare förbättra logistikstrukturen. Metod – En omfattande metodik har använts, där både kvalitativa och kvantitativa aspekter har analyserats. Genom intervjuer och observationer har data samlats in för att skapa en holistisk förståelse för nuvarande logistikflöde och eventuella alternativa lösningar. Resultat och diskussion – Den omfattande analysen av Essitys nuvarande logistikflöde avslöjar viktiga insikter. Den befintliga metoden, med intern transport till externa lager, visar sig vara ekonomiskt gynnsam, särskilt när kontrakterade kostnader för externa lager och andra projektrelaterade utgifter för år 2023 beaktas. Det är värt att notera att de ekonomiska data för en alternativ lösning från en potentiell 3PL-leverantör gäller för år 2025. För att förstå möjliga förändringar i kostnader över tid har hänsyn tagits till den potentiella ökningen av kostnaderna för den befintliga metoden. Diskussionen inkluderar också miljöaspekter, där olika lösningar övervägs för att identifiera den mest hållbara och lönsamma strategin för Essitys logistik. Lösning 2, som involverar byggandet av ett nytt lager (green warehouse) och användning av elfordon och HVO-drivna lastbilar, presenterar sig som en hållbar inriktning som kan minska CO2-utsläppen och bidra till Essitys övergripande mål att minska miljöpåverkan. Rekommendationer för Essity – Baserat på resultaten av analysen rekommenderas Essity att genomföra en benchmarking för att undersöka erbjudanden från andra potentiella 3PL- leverantörer. Förhandlingar med det nuvarande externa lagret för att förbättra prisstrukturen bör övervägas, särskilt med tanke på de betydande totala kostnaderna för båda lösningarna. Slutligen bör Essity överväga att göra en strategisk investering i att bygga ett utökat manuellt lager nära det befintliga, vilket kan möjliggöra ökad flexibilitet och kostnadseffektivitet över tiden. / Background – Essity, a prominent player in the hygiene and health industry, faces challenges regarding the logistics flow for consumer products from its production facility in Lilla Edet to customers in Denmark. The current logistics process involves internal transportation with company-owned trucks to external warehouses. In this context, ensuring swift and cost- effective deliveries while maintaining customer satisfaction is of utmost importance. Purpose – The project aims to analyze and optimize Essity's current logistics flow for consumer products. The focus is on identifying potential improvements to ensure smooth and efficient deliveries to the Danish market. A central part of the investigation also involves considering the integration of a third-party logistics partner (3PL) to further enhance the logistics structure. Method – A comprehensive methodology has been employed, analyzing both qualitative and quantitative aspects. Through interviews and observations, data has been collected to gain a holistic understanding of the current logistics flow and potential alternative solutions. Results and Discussion – The extensive analysis of Essity's current logistics flow reveals crucial insights. The existing method, involving internal transport to external warehouses, proves to be economically advantageous, especially when considering contracted costs for external warehouses and other project-related expenses for the year 2023. It is worth noting that the economic data for an alternative solution from a potential 3PL provider applies to the year 2025. To understand possible changes in costs over time, considerations have been made for the potential increase in costs for the existing method. The discussion also includes environmental aspects, where different solutions are considered to identify the most sustainable and profitable strategy for Essity's logistics. Solution 2, involving the construction of a new warehouse (green warehouse) and the use of electric vehicles and HVO-driven trucks, presents itself as a sustainable approach that can reduce CO2 emissions and contribute to Essity's overall goal of reducing environmental impact. Recommendations for Essity – Based on the results of the analysis, Essity is recommended to conduct a more in-depth benchmarking to explore offerings from other potential 3PL providers. Negotiations with the current external warehouse to improve the price structure should be considered, especially considering the significant total costs for both solutions. Finally, Essity should contemplate making a strategic investment in building an expanded manual warehouse near the existing one, enabling increased flexibility and cost-effectiveness over time.

The Swedish heavy vehicle manufacturer Scania is currently phasing out their main engine assembly line in favor of a new assembly line. As a consequence, there is a need to adjust the logistics to the phase-out to maintain efficiency and free up space. Due to a lack of literature on this particular subject, it has been noticed that both Scania and the literature could benefit from a theoretical methodology that provides general guidance on how to approach reductions in production volume from a logistics perspective. To explore this problem the study answers the research question ”How can heavy vehicle manufacturing companies optimize inventory space at an assembly line when the production volume decreases?”. The study focused on a smaller internal logistics area within Scania’s Södertälje assembly plant, to develop a theoretical methodology that is also applicable to other areas and companies facing similar challenges. The phase-out will be executed in stages, starting with the most common engine types. The production volume will be reduced by changing the takt and removing engine carriers. Takt is a term used to describe the time that an engine spends at each assembly line station. The reduction in production volume leads to a proportional reduction in the amount of material picked at the logistics platforms. Consequently, the material stays in stock for a longer time, and the efficiency of the material handlers decreases. To maintain the stocking times and efficiency of the material handler, the study found that packaging sizes should be reduced in proportion to the production volume, as this would enable the storage to hold fewer items of each article while also holding a larger variety of articles previously stored elsewhere. As a result, additional activities can be given to the material handlers, while also freeing up inventory space that can be used to introduce the new assembly line. Approaching these challenges can be done following the theoretical methodology that has been developed in this study, consisting of three steps: Overview of Potential Changes, Quantifying Inventory Changes, and Calculating Inventory Space. Guided by this theoretical methodology, the study identified that the main potential changes revolved around packaging sizes. Changes in packages were then quantified for the 220 articles stored in the logistics area and synchronized with the phase-out to maintain the current stocking times. At the first step of the phase-out, when the takt is reduced to 3/4-takt, 107 packages could be changed, resulting in a 34% reduction in inventory space, indicating that one of the three logistics platforms in the logistics area can be closed. In the following stages of the phase-out, the further reduction in inventory space is marginal resulting in a final reduction of 46% at 1/3-takt, which might suggest that other approaches are more beneficial later on. As a result of this study, companies facing challenges adjusting the logistics to reduced production volumes can find guidance in the theoretical methodology presented in this thesis. The theoretical methodology highlights important aspects to consider based on both literature and empirical findings from the case study so that the efficiency of the logistics can be maintained during assembly line phase-out / Den svenska lastbilstillverkaren Scania håller för närvarande på att fasa ut en av deras primära monteringslinor för att ersätta denna med en ny. En konsekvens av detta är att den interna logistiken måste anpassas för att behålla dess effektivitet och frigöra lageryta. I dagsläget är litteraturen inom detta ämne begränsad, vilket innebär att både Scania och litteraturen som helhet gynnas av en teoretisk metodik som generellt beskriver hur intern logistik kan anpassas vid varierande produktionsvolymer. För att undersöka detta besvarar denna studie forskningsfrågan ”Hur kan tunga fordonstillverkare optimera lageryta vid monteringslinor vid minskad produktionsvolym?”. Studien fokuserar på ett mindre internt logistikområde vid Scanias motormonteringsanläggning i Södertälje. Målet är att inom detta område presentera en teoretisk metod som är applicerbar på samtliga logistikområden på Scania, såväl som hos andra företag med liknande utmaningar. Scania planerar att genomföra utfasningen stegvis, där det första steget innebär att de vanligaste motortyperna fasas ut och övergår till den nya monteringslinan. Produktionsvolymen kommer att minskas genom taktminskning, samt genom att plocka bort ”carriers” (stativen som motorerna monteras på). Takt är en term som beskriver den tid varje enskild motor befinner sig vid varje monteringsstation. Den minskade produktionsvolymen innebär en proportionell minskning i åtgång av komponenter och produktionsmaterial. Till följd av detta ökar lagertiden och effektiviteten för materialhanterarna minskar. För att bibehålla lagertiden och effektiviteten visade studien att förpackningsstorlekarna borde minskas, vilket innebär att färre artiklar lagerhålls, samt att fler varianter av artiklar kan lagras på mindre yta. Vidare kan materialhanterarna tilldelas fler arbetsuppgifter och den frigjorda yta utnyttjas av den nya monteringslinan. Dessa utmaningar kan hanteras enligt följande metodik med tre steg: 1. Överblick över möjliga ändringar, 2. Kvantifiera möjliga lagerbesparingar och 3. Beräkna lagerbesparingar. Baserat på denna metodik, fann studien att den största potentialen fanns genom ändrade förpackningsstorlekar. Förpackningsändringarna kvantifierades för de 220 artiklarna inom det behandlade området, med hänsyn till taktreduceringen och bibehållen lagertid. Vid första nedrampningssteget när takten reducerats till 3/4, visade studien att 107 förpackningsändringar kunde genomföras, vilket resulterade i en reducering av lageryta på 34%. I praktiken innefattade denna minskning i krävd lageryta att en av tre logistikplattformar inom logistikområdet kan stängas ned. Vid efterföljande nedrampningssteg var lagerbesparingarna marginella med en slutlig reduktion på 46% vid 1/3-takt, vilket implicerar att andra aspekter borde beaktas senare under nedrampningsprocessen.  Avslutningsvis poängterar studien att företag med liknande utmaningar gällande logistik och reducerade produktionsvolymer kan finna vägledning med hjälp av den teoretiska metod som presenterats i denna studie. Denna metod belyser viktiga aspekter som måste beaktas, baserat på litteratur så väl som empiriska resultat från fallstudien. Detta med fokus på att bibehålla effektiviteten och minimera lageryta vid nedrampning av monteringslinor.

<p><p>To be a market leader, low cost and responsiveness are the key success factors. Logistics activities create high cost reducing competitiveness of the company, especially for the remote production base. Thus, logistics activities which are delivery planning, freight forwarder and delivery mode selection must be optimized. The focusing area of this paper is inbound logistics due to its big proportion in the total cost and involvement with several stakeholders. The optimization theory and Microsoft Excel’s Solver is used to create the standard optimization tools since it is an efficient and user friendly program. The models are developed based on the supply chain management theory in order to achieve the lowest cost, responsiveness and shared objectives. 2 delivery planning optimization models, container loading for fixed slitting and loading pattern and container loading for pallet loaded material, are formulated. Also, delivery mode selection is constructed by using optimization concept to determine the best alternative. Furthermore, freight forwarder selection process is created by extending the use of the delivery mode selection model. The results express that safety stock, loading pattern, transport mode, and minimum order quantity (MOQ) significantly affect the total logistics cost. Including hidden costs, long transit time and delay penalties, leads freight forwarder selection process to become more realistic and reliable. Shorter processing time, ensured optimal solution, transparency increase and better communication are gained by using these optimization models. However, the proper boundaries must be defined carefully to gain the feasible solution.</p></p>

To be a market leader, low cost and responsiveness are the key success factors. Logistics activities create high cost reducing competitiveness of the company, especially for the remote production base. Thus, logistics activities which are delivery planning, freight forwarder and delivery mode selection must be optimized. The focusing area of this paper is inbound logistics due to its big proportion in the total cost and involvement with several stakeholders. The optimization theory and Microsoft Excel’s Solver is used to create the standard optimization tools since it is an efficient and user friendly program. The models are developed based on the supply chain management theory in order to achieve the lowest cost, responsiveness and shared objectives. 2 delivery planning optimization models, container loading for fixed slitting and loading pattern and container loading for pallet loaded material, are formulated. Also, delivery mode selection is constructed by using optimization concept to determine the best alternative. Furthermore, freight forwarder selection process is created by extending the use of the delivery mode selection model. The results express that safety stock, loading pattern, transport mode, and minimum order quantity (MOQ) significantly affect the total logistics cost. Including hidden costs, long transit time and delay penalties, leads freight forwarder selection process to become more realistic and reliable. Shorter processing time, ensured optimal solution, transparency increase and better communication are gained by using these optimization models. However, the proper boundaries must be defined carefully to gain the feasible solution.