Högre krav ställs på effektivitet och optimering av flödet hos distribuerande företag för att kunna möta det ökade antalet varor som hanteras. För att möta detta krav krävs ledtidsreducering i form av att minska icke värdeskapande tid samt att fokusera på arbetsmiljö för medarbetarna, i form av ergonomi. Ett stort fokus ligger även på att tillfredsställa kund i form av att leverera rätt kvalitet i rätt tid. Syftet med arbetet är att få en förståelse för effektiviseringsmöjligheter inom lagerhantering på ett distribuerande företag och utveckla ett arbetssätt som minskar ledtiden och förbättrar arbetsmiljön med fokus på ergonomi. Målet med studien är att ta fram ett effektivare arbetssätt i form av minskad ledtid och bättre arbetsmiljö, där fokus är ergonomi. Frågeställningar som tagits fram för att uppnå syftet berör hur ett distribuerande företag kan hantera lager på ett effektivare sätt i form av minskad ledtid samt hur lagerhanteringen kan förbättras med avseende på arbetsmiljön och dess ergonomiska aspekter. En värdeflödesanalys har tagits fram baserat på observationer och mätningar. I värdeflödesanalysen framgick det att processerna för inregistrering av paket och plock av paket hade förbättringsmöjligheter. Tester har utförts för att undersöka om olika förbättringsförslag medfört minskad ledtid och förbättrad arbetsmiljö i form av ergonomi. Resultatet visar att ett nytt arbetssätt tillsammans med en ny layout minskar ledtiden samtidigt som arbetsmiljön förbättras då personalen rör sig mindre. Slutsatsen är att ett effektivare och mer ergonomiskt arbetssätt gynnar företaget, medarbetare och kunder. / Higher demands are placed on efficiency and optimization of the flow of distribution centers due to the higher amount of products they are handling. To meet this requirement, lead time reduction is required to reduce non-value-adding time and focus on the work environment for a better ergonomics. Another important thing is to satisfy the customer in order to deliver the right quality on the right time. The purpose of the work is to gain an understanding of efficiency opportunities in warehouse management at a distributing company and to develop a working method that reduces lead time and improves the work environment with a focus on ergonomics. The aim of the study is to develop a more efficient way of working to reduce lead time and develop a better work environment, where the focus is on ergonomics. Issues that were developed to achieve the purpose of this case study concern how a distribution company can handle inventory in a more efficient way in the form of reduced lead time and how inventory management can be improved regarding work environment and ergonomic aspects. A value flow analysis was created based on observations and measurements. The value flow analysis showed that two different processes had opportunities for improvement. Tests have been performed to investigate if different improvements could reduce lead time and improve the work environment. The results showed that a new way of working together with a new layout reduced lead time. The conclusion shows that a more efficient and ergonomic way of working benefits the company, the employees, and the customer.

Magister Public Health - MPH / The introduction of National Health Insurance (NHI) and the Ideal Clinic Monitoring System have highlighted gaps and challenges with regard to medicine supply management (MSM) at primary health care (PHC) facilities. PHC facilities are the first point of contact communities have for their health needs, however, frequent stock-outs of medicines at PHC facilities in uMkhanyakude district, a rural district in KwaZulu-Natal, and have raised questions as to how medicine stock is managed at these facilities.

En la actualidad, en la industria de alimentos se ha diagnosticado un exponencial crecimiento en la demanda, en todos los rubros pertenecientes a este sector. Uno de estos es la industria de panificación, en la que el principal motivo de desarrollo, crecimiento y cambio son las exigencias de los clientes vinculados a criterios como precios reducidos, aumento de la calidad, variedad de productos entre otras variables que una empresa debe tener en cuenta para ser competitiva en el sector, y a su vez mantener un nivel de rentabilidad y margen de contribución. Para ello, es indispensable tener una correcta planificación de cada proceso considerando con igual importancia tanto al proceso de producción como a los adyacentes a este. Dichos procesos se vinculan a la compra de las materias primas en calidad, precio o tiempos de recepción, el cálculo preciso del pronóstico de la demanda y la correcta gestión de inventarios que son indispensables para asegurar un producto final de calidad al alcance del cliente. El presente artículo propone un nuevo modelo que se basa en el uso del enfoque lean y técnicas combinadas para lograr un competitivo manejo de los procesos mencionados anteriormente. Para ello, se plantea el uso conjunto de herramientas tales como la homologación de proveedores, MRP, lote económico de compra de materiales (EOQ) y estandarización de proceso de trabajo, para mejorar los problemas relacionados a una producción defectuosa por una mala gestión de materiales que asciende a un índice actual de 11.43%. Luego de la implementación de la propuesta se obtuvo una reducción de aproximadamente el 58% de ella como sustento de la efectividad del método y su corroboración a la mejora continua con una simulación llegando a verificar los resultados. / Currently, an exponential growth in demand has been diagnosed in the food industry, in all items belonging to this sector. One of these is the baking industry, in which the main reason for development, growth and change are the demands of customers linked to criteria such as reduced prices, increased quality, variety of products, among other variables that a company must have. in account to be competitive in the sector, and in turn maintain a level of profitability and contribution margin. For this, it is essential to have a correct planning of each process considering with equal importance both the production process and those adjacent to it. These processes are linked to the purchase of raw materials in quality, price or reception times, the precise calculation of the demand forecast and the correct inventory management that are essential to ensure a quality final product available to the customer. This article proposes a new model that is based on the use of the lean approach and combined techniques to achieve a competitive management of the processes mentioned above. For this, the joint use of tools such as supplier approval, MRP, economic materials purchase lot (EOQ) and standardization of the work process is proposed, to improve the problems related to defective production due to poor material management which amounts to a current rate of 11.43%. After the implementation of the proposal, a reduction of approximately 58% was obtained in support of the effectiveness of the method and its corroboration to continuous improvement with a simulation, verifying the results. / Trabajo de investigación

El presente trabajo de investigación se elabora a partir de la necesidad de reducir los niveles de inventario de producto terminado en la empresa Calzatura Moreyka, lo cual representa dinero inmovilizado, que posteriormente se convertirán en costos. Por ello, se trabajará en la disminución de estos inventarios como tema principal, buscando optimizar la gestión de inventarios que existe actualmente. Para lograr dicho objetivo, se propone la utilización de la metodología Collaborative Planning Forecasting and Replenishment (CPFR) junto con los pronósticos ARIMA, mejorando la gestión de inventarios e implementando la predicción del comportamiento de la demanda. Esta mejora se obtendrá a través de la mejora de los procesos como de los correctos pronósticos a realizarse. El proyecto está dividido en 4 capítulos. Durante el capítulo 1 se formulará el problema principal de acuerdo con los antecedentes presentes en el sector, los objetivos y la propuesta de solución que abarcan las posibles técnicas a utilizar para atacar las causas que originan el problema. Asimismo, se realizará el marco teórico y el estado del arte explicando casos de éxito sobre la utilización de las técnicas de solución planteadas. En el capítulo 2 se realizará el diagnóstico sobre la situación actual de la organización identificando los procesos de la empresa, el impacto y el análisis de las causas del problema. En el capítulo 3 se desarrollará todo lo correspondiente a la propuesta buscando que la hipótesis planteada pueda reducir el problema. Finalmente, el capítulo 4 consiste en la aplicación y validación evaluando el impacto que se obtuvo de la propuesta planteada. / This research work is developed from the need to reduce the inventory levels of finished product in the Calzatura Moreyka Company, which represents immobilized money, which will later be converted into costs. For this reason, work will be done on reducing these inventories as the main issue, seeking to optimize the inventory management that currently exists. To achieve this objective, the use of the Collaborative Planning Forecasting and Replenishment (CPFR) methodology is proposed together with the ARIMA forecasts, improving inventory management and implementing the prediction of demand behavior. This improvement will be obtained through the improvement of the processes and the correct forecasts to be made. The project is divided into 4 chapters. During Chapter 1, the main problem will be formulated according to the antecedents present in the sector, the objectives and the proposed solution that includes the possible techniques to be used to attack the causes that originate the problem. Likewise, the theoretical framework and the state of the art will be carried out, explaining success stories about the use of the proposed solution techniques. In chapter 2 the diagnosis of the current situation of the organization will be carried out, identifying the company's processes, the impact and the analysis of the causes of the problem. In chapter 3 everything corresponding to the proposal will be developed, seeking that the hypothesis proposed can reduce the problem. Finally, chapter 4 consists of the application and validation evaluating the impact obtained from the proposed proposal. / Trabajo de Suficiencia Profesional

En metod som används för lagerstyrning, och som fått ökat intresse inom forskningen de senaste åren, är klassificering med multipla kriterier (MCABC). Däremot har forskningen hittills tenderat att koncentrera sig på utveckling av klassificeringsmodeller snarare än på vägledning för tillämpning av modellerna. Studien påvisade med en litteraturstudie att forskningsområdet klassificering med multipla kriterier hade en begränsad mängd vägledning för tillämpning relativt mängden klassificeringsmodeller som utformats. Därför undersökte studien en modifierad lagerstyrningsstrategi. Syftet med studien var att finna produkter som lämpar sig för lagring av produktionskapacitet och att undersöka effekterna på färdigvarulagret om dessa produkter används för lageruppbyggnad inför säsongen. För att finna sådana produkter utformades en klassificeringsmodell med multipla kriterier, GTS-modellen (Good to Store). Modellen testades genom att ett antal scenarier simulerades på ett urval av produkter av det egentillverkade sortimentet i en fabrik. Detta gjordes i en fallstudie av ett företag inom processindustrin vars sortiment har säsongsvariationer. Resultatet av simuleringarna visade att lageruppbyggnad med GTS-modellen inför säsongen innebar att det genomsnittliga lagervärdet och antalet omställningar för det egentillverkade sortimentet minskade med ungefär 14 % vardera, jämfört med nuläget. Samtidigt kunde servicenivån bibehållas på i princip identisk nivå. Görs motsvarande jämförelse enbart på den simulerade delen av sortimentet blir minskningarna ungefär 35 % vardera. / Multi criteria classification (MCABC) is a method used for inventory management which has gained interest in research in recent years. However, research has tended to focus on the development of classification models rather than guidance on the application of the models. This study demonstrated, using a literature review, that the multi criteria classification field had a limited amount of guidance for application compared to the amount of classification models that were developed. Therefore, this study examined a modified inventory management strategy. The purpose of the study was to find products suitable for storing production capacity and to examine the effects on the finished goods inventory if these products are used for stock build-up prior to the season. A multi criteria classification model, the GTS (Good to Store) model, was developed to find such products. The model was tested by simulating several scenarios on a selection of products from the factory-made range. This was conducted in a case study regarding a company in the process industry whose range has seasonal variations. The simulations showed that stock build-up with the GTS model prior to the season resulted in an approximately 14 % decrease in average inventory value and number of setups for the factory-made range, compared to the current situation. At the same time, the service level was almost completely maintained. If the comparison is made exclusively on the simulated part of the assortment, the decrease will be approximately 35 %.

Tesis por compendio / [ES] La gestión sostenible de las cadenas de suministro se ha transformado en un tema de alto interés entre profesionales e investigadores en el ámbito de la ingeniería industrial. El impacto que generan las actividades económicas en el medioambiente y en las comunidades donde éstas se ubican ha generado un incremento en el desarrollo de herramientas que permitan incorporar dichos impactos en las decisiones tomadas en el nivel estratégico de las empresas e industrias. Es así como surgen nuevos paradigmas respecto al modelo de producción, como por ejemplo la economía circular, donde se busca transitar desde una economía de producción lineal, hacia una circular reduciendo al mínimo la generación de desperdicios, ya sea material y/o energético. En este contexto, esta tesis doctoral, sustentada en una revisión de la literatura y en un análisis de modelos de optimización matemática de referencia, propone un marco conceptual como herramienta de soporte para seguir desarrollando modelos cuantitativos para dar soporte a los problemas de localización, inventario y transporte (LIT) en cadenas de suministro sostenibles, así como, un modelo de optimización multiobjetivo no lineal entero mixto (MOMINLP) para diseñar una cadena de suministro sostenible de bucle cerrado considerando las decisiones LIT, donde los aspectos de sostenibilidad: económico, medioambiental y social son incorporados en cada una de las decisiones anteriores. El modelo propuesto, denominado 3S-LIT, considera cuatro funciones objetivo que pretenden: (1) minimizar el coste total de la cadena de suministro; (2) minimizar los costes asociados a la emisión de CO2 equivalente; (3) minimizar el coste social relacionado con los accidentes laborales; y (4) maximizar el impacto social, medido como el incremento en cuanto a la generación de empleos directos e indirectos y la reducción en la cantidad de personas afectas por los riesgos del transporte dentro de la cadena de suministro. El modelo 3S-LIT ha sido validado en una empresa del sector minero del cobre obteniendo un mejor desempeño en los valores de las funciones objetivo respecto a los obtenidos en la situación actual. Además, el modelo 3S-LIT se ha comparado con un enfoque existente en la literatura científica obteniéndose unos resultados satisfactorios tanto en términos de funcionalidades como de resultados. Finalmente, el modelo propuesto de optimización matemática, 3S-LIT, es replicado en un modelo de simulación con el cual se estudiaron posibles escenarios de disrupción de la cadena de suministro con el objetivo de analizar su capacidad resiliente. / [CA] La gestió sostenible de les cadenes de subministrament s'ha transformat en un tema d'alt interès entre professionals i investigadors en l'àmbit de l'enginyeria industrial. L'impacte que generen les activitats econòmiques en el medi ambient i en les comunitats on aquestes se situen ha generat un increment en el desenvolupament d'eines que permeten incorporar aquests impactes en les decisions preses en el nivell estratègic de les empreses i indústries. És així com sorgeixen nous paradigmes respecte al model de producció, com per exemple l'economia circular, on se cerca transitar des d'una economia de producció lineal, cap a una circular reduint al mínim la generació de desaprofitaments, ja siga material i/o energètic. En aquest context, aquesta tesi doctoral, sustentada en una revisió de la literatura i en una anàlisi de models d'optimització matemàtica de referència, proposa un marc conceptual com a eina de suport per a continuar desenvolupant models quantitatius per a donar suport als problemes de localització, inventari i transport (LIT) en cadenes de subministrament sostenibles, així com, un model d'optimització multi-objectiu no lineal enter mixt (MOMINLP) per a dissenyar una cadena de subministrament sostenible de bucle tancat considerant les decisions LIT, on els aspectes de sostenibilitat: econòmic, mediambiental i social són incorporats en cadascuna de les decisions anteriors. El model proposat, denominat 3S-LIT, considera quatre funcions objectiu que pretenen: (1) minimitzar el cost total de la cadena de subministrament; (2) minimitzar els costos associats a l'emissió de CO2 equivalent; (3) minimitzar el cost social relacionat amb els accidents laborals; i (4) maximitzar l'impacte social, mesurat com l'increment quant a la generació d'ocupacions directes i indirectes i la reducció en la quantitat de persones afectes pels riscos del transport dins de la cadena de subministrament. El model 3S-LIT ha sigut validat en una empresa del sector miner del coure obtenint un millor acompliment en els valors de les funcions objectiu respecte als obtinguts en la situació actual. A més, el model 3S-LIT s'ha comparat amb un enfocament existent en la literatura científica obtenint-se uns resultats satisfactoris tant en termes de funcionalitats com de resultats. Finalment, el model proposat d'optimització matemàtica, 3S-LIT, és replicat en un model de simulació amb el qual es van estudiar possibles escenaris de disrupció de la cadena de subministrament amb l'objectiu d'analitzar la seua capacitat resilient. / [EN] Sustainable supply chain management has become a topic of great interest among practitioners and researchers in the field of industrial engineering. The impact generated by economic activities on the environment and the communities where they are located has generated an increase in the development of tools that allow the incorporation of these impacts in the decisions taken at the strategic level of companies and industries. This is how new paradigms emerge regarding the production model, such as the Circular Economy, which seeks to move from a linear production economy to a circular one by minimising the generation of waste, both material and energetic. In this context, this PhD thesis, supported by a state-of-the-art study and the analysis of benchmark mathematical optimisation models, presents a conceptual framework to provide the key elements that act as a valuable tool to further develop quantitative models of location, inventory and transport (LIT) problems in sustainable supply chains, and a novel mixed integer non-linear multi-objective mixed integer multi-objective optimisation model (MOMINLP) for designing a closed-loop sustainable supply chain considering location, inventory and transportation decisions, where economic, environmental and social sustainability aspects are incorporated in each of the above mentioned decisions. The proposed model, called 3S-LIT, considers four objective functions that aim to: (1) minimise the total cost of the supply chain, (2) minimise the costs associated with CO2 equivalent emissions, (3) minimise the social cost related to occupational accidents, and (4) maximise the social impact, measured as a higher generation of direct and indirect jobs and a lower number of people affected by transport risks within the chain. The 3S-LIT model has been applied in a company in the copper mining sector, confirming a better performance in the values of the objective functions compared to those obtained in the current situation. In addition, the mathematical optimisation model is replicated in a simulation model with which possible supply chain disruption scenarios were studied to analyse the resilience of the supply chain. / This thesis has been developed within the Research Centre on Production Management and Engineering (CIGIP) of the Universitat Politècnica de València, within the framework of the projects: "Industrial Production and Logistics Optimization in Industry 4.0" (i4OPT) (Ref. PROMETEO/2021/065) granted by the Valencian Regional Government and received funding from Grant RTI2018-101344-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”; “Validation of transferable results of optimisation of zero-defect enabling production technologies for supply chain 4.0” (CADS4.0-II) from the grant PDC2022-133957-I00; and by European Union Next GenerationEU/PRTR, and from the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101070076 "Optimizing Production and Logistic Resources in the Time-critical Bio Production Industries in Europe" (CLARUS). It was also funded by the National Agency for Research and Development (ANID)/Scholarship Program/Doctorado Becas en el Extranjero/2020 – 72210174 and sponsored by the Universidad de Atacama as part of an academic improvement plan. / Becerra Muñoz, PA. (2023). Quantitative Models of Location, Inventory and Transportation Decisions for Sustainable Supply Chain Management [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196651 / Compendio

Магистерская диссертация посвящена разработке методического инструментария, направленного на совершенствование системы управления оборотными средствами на предприятии. В качестве научной новизны выявлена обратно-пропорциональная корреляция между рентабельностью оборотных активов и оборачиваемостью запасов предприятия, а также установлена обратно-пропорциональная зависимость между инфляцией и оборачиваемостью запасов. Автором предложен методический подход к определению потребности в запасах материалов на основе календарного плана-графика, разработаны методические основы для внедрения категорийного подхода к управлению закупками на предприятии. Полученные результаты и рекомендации могут использоваться специалистами предприятий при разработке тактических и стратегических мероприятий по управлению оборотными средствами. / The master's thesis is devoted to the development of methodological tools aimed at improving the working capital management system at the enterprise. As a scientific novelty, an inversely proportional correlation between the profitability of current assets and the turnover of stocks of the enterprise was revealed, and an inversely proportional relationship between the turnover of stocks and inflation was also established. The author has proposed a methodological approach to determining the need for stocks of materials based on a calendar schedule, developed methodological foundations for introduction of a categorical approach to procurement management at enterprise. The obtained results and recommendations can be used by specialists of enterprises in the development of tactical and strategic management measures for working capital.

This thesis work aims to improve the stock management system of Excillum AB, a Stockholm-based company that specializes in high-performance X-ray sources. The current stock management system has limitations, resulting in gaps when managing the inventory. To address this, the study focuses on developing a calculation model that takes into account various factors such as the global supply chain, customer expectations, service offerings, and financial concerns. The research questions revolve around understanding best practices in stock management from other companies, considerations for stock selection and ordering decisions, and additional parameters to ensure accurate safety stock calculations. The research involves carrying out a literature review, benchmarking practices from other organizations, analyzing Excillum's transaction data, and developing a reliable calculation model. However, some limitations exist, such as relying on Excel for calculations rather than changing values within the ERP system, which reduces demand projection accuracy due to high product customization. Human factors and unavoidable supply chain disruptions are not specifically addressed in the recommended approach. The proposed calculation model aims to improve stock management efficiency, ensure product availability, reduce stockouts, and ultimately contribute to Excillum's growth goals while meeting customer demands. Excillum can optimize stock levels and streamline inventory management by incorporating best practices and taking into account critical factors, establishing the way for long-term success and improved customer satisfaction. / Detta examensarbete syftar till att förbättra lagerhanteringssystemet för Excillum AB, ett Stockholmsbaserat företag som är specialiserat på högpresterande röntgenkällor. Det nuvarande lagerhanteringssystemet har begränsningar, vilket resulterar i luckor vid hanteringen av lagret. För att komma till rätta med detta fokuserar studien på att utveckla en beräkningsmodell som tar hänsyn till olika faktorer såsom den globala leveranskedjan, kundernas förväntningar, tjänsteerbjudanden och ekonomiska problem. Forskningsfrågorna kretsar kring att förstå bästa praxis inom lagerhantering från andra företag, överväganden för aktieval och beställningsbeslut och ytterligare parametrar för att säkerställa korrekta beräkningar av säkerhetslager. Forskningen innebär att man genomför en litteraturgenomgång, benchmarking praxis från andra organisationer, analyserar Excillumstransaktionsdata och utvecklar en tillförlitlig beräkningsmodell. Det finns dock vissa begränsningar, som att förlita sig på Excel för beräkningar snarare än att ändra värden inom ERP-systemet, vilket minskar noggrannheten i efterfrågeprojekteringen på grund av hög produktanpassning. Mänskliga faktorer och oundvikliga störningar i försörjningskedjan behandlas inte specifikt i den rekommenderade metoden. Den föreslagna beräkningsmodellen syftar till att förbättra lagerhanteringseffektiviteten, säkerställa produkttillgänglighet, minska lagerutbudet och i slutändan bidra till Excillumstillväxtmål samtidigt som kundernas krav tillgodoses. Excillum kan optimera lagernivåer och effektivisera lagerhantering genom att införliva bästa praxis och ta hänsyn till kritiska faktorer, etablera vägen för långsiktig framgång och förbättrad kundnöjdhet.

M. Tech. (Department of Process Control and Computer Systems, Faculty of Engineering and Technology), Vaal University of Technology. / Radio Frequency Identification Technology (RFID) technology is increasingly being used in multiple applications due to its low cost and ability to provide a high quality of identification. The cost benefit of RFID system is seen in the reduction in labor required to perform routine tasks such as inventory. With RFID, inventory-related tasks can be done in substantially less time compared to other commonly used auto-identification systems. Recent research has illustrated the application of RFID in multiple application scenarios. RFID can be used for real-time patient identification and monitoring in hospitals, but also for product expiration-date management in retail industries. Some enterprises in South Africa uses a combination of RFID technology and Internet of Things (IoT) to detect misplaced products and to detect low stock levels. Furthermore, RFID is also used for inventory management in libraries as discussed in this dissertation. In this dissertation, a combination of RFID and ZigBee technologies was used to reduce the time spent to perform inventory in libraries. An inventory management system was designed, simulated and built in order to count and locate books inside a library hence improving inventory process time in libraries. The overall results were satisfactory which lead to the achieving of the objectives set in this study.

The central thesis of this dissertation is that by combining classical scheduling methodologies with those of inventory management and queueing theory we can better model, understand and solve complex real-world scheduling problems. In part II of this dissertation, we provide models of a realistic supply chain scheduling problem that capture both its combinatorial nature and its dependence on inventory availability. We present an extensive empirical evaluation of how well implementations of these models in commercially available software solve the problem. We are therefore able to address, within a specific problem, the need for scheduling to take into account related decision-making processes. In order to simultaneously deal with combinatorial and dynamic properties of real scheduling problems, in part III we propose to integrate queueing theory and deterministic scheduling. Firstly, by reviewing the queueing theory literature that deals with dynamic resource allocation and sequencing and outlining numerous future work directions, we build a strong foundation for the investigation of the integration of queueing theory and scheduling. Subsequently, we demonstrate that integration can take place on three levels: conceptual, theoretical and algorithmic. At the conceptual level, we combine concepts, ideas and problem settings from the two areas, showing that such combinations provide insights into the trade-off between long-run and short-run objectives. Next, we show that theoretical integration of queueing and scheduling can lead to long-run performance guarantees for scheduling algorithms that have previously been proved only for queueing policies. In particular, we are the first to prove, in two flow shop environments, the stability of a scheduling method that is based on the traditional scheduling literature and utilizes processing time information to make sequencing decisions. Finally, to address the algorithmic level of integration, we present, in an extensive future work chapter, one general approach for creating hybrid queueing/scheduling algorithms. To our knowledge, this dissertation is the first work that builds a framework for integrating queueing theory and scheduling. Motivated by characteristics of real problems, this dissertation takes a step toward extending scheduling research beyond traditional assumptions and addressing more realistic scheduling problems.