Operations Research, Systems Engineering and Industrial Engineering Commons^™

Optimal Allocation Of Resources In Reliability Growth, Mohammadhossein Heydari

Graduate Theses and Dissertations

Reliability growth testing seeks to identify and remove failure modes in order to improve system reliability. This dissertation centers around the resource allocation across the components of a multi-component system to maximize system reliability. We summarize this dissertation’s contributions to optimal resource allocation in reliability growth.

Chapter 2 seeks to deploy limited testing resources across the components of a series-parallel system in effort to maximize system reliability under the assumption that each component’s reliability exhibits growth according to an AMSAA model with known parameters. An optimization model for this problem is developed and then extended to consider the allocation of …

A Multi-Objective Affinity-Based Savings Algorithm For Improving Processes In Centralized Warehousing Operations, Mckenlee M. Coco

Graduate Theses and Dissertations

Traditional approaches to improving material management processes in warehousing operations tend to focus on one of three major areas: facility design, order picking and sorting, and order batching. In an effort to improve total system savings, a new affinity function is developed and applied to batching logic to create a multi-objective problem. The proposed multi-objective function incorporates user input to increase adaptability to changing demand and flexibility to changing requirements. Computational experience shows the new function leads to solutions that deviate no more than 25% from the most efficient distance based picking route by the same batching logic, while creating …

Essays On Applications Of Transportation Network Design And Optimization, Amirali Ghaharikermani

Graduate Theses and Dissertations

In this dissertation, we address different transportation problems. The three main outcomes are: designing a battery swap station network, studying gaps in Empty Container Management literature, designing a model with similar characteristics to the vehicle routing problem as well as implementation scenario for it to be applied for a real-world case.

For the designed battery swap station, a model is developed for customer demand satisfaction that permits construction of different types of BSS in the planning network. Our solution methodology is a Tabu Search algorithm combined with a dynamic programming initialization. Numerous tests showed that the proposed TS approach provides …

Demonstrating Set-Based Design Techniques- A Uav Case Study, Colin Small

Graduate Theses and Dissertations

The Department of Defense (DoD) and Engineered Resilient Systems (ERS) community seek to improve decision making in the Analysis of Alternatives (AoA) process by incorporating resilience and leveraging the capabilities of model-based engineering (MBE) early in the design process. Traditional tradespace exploration utilizing Point-Based Design (PBD) often converges quickly on a solution with subsequent engineering changes to modify the design. However, this process can lead to a suboptimal solution if an incorrect initial solution is chosen. Enabled by MBE, Set-Based Design (SBD) considers sets of all possible solutions and enables down-selecting possibilities to converge on a final solution. Using a …

Convergent Set-Based Design In Integrated Analysis Of Alternatives: Designing Engineered Resilient Systems, Zephan Wright Wade

Graduate Theses and Dissertations

This thesis presents a comprehensive package for understanding and expanding set-based design quantification through the definition and demonstration of Convergent set-based design (SBD). Convergent SBD is a technique developed for the Engineered Resilient Systems program sponsored by the Department of Defense. Convergent SBD contributes a repeatable methodology with the goal of mathematically eliminating inefficient sets. The study of Convergent SBD led to the development of dominance identification criteria equations using comparison of statistical means. The demonstration of Convergent SBD also illustrates the effect of mission resilience in the tradespace and the impact mission resilience has on preference. Finally, Convergent SBD …

Systematic Review For Water Network Failure Models And Cases, Yufei Gao

Graduate Theses and Dissertations

As estimated in the American Society of Civil Engineers 2017 report, in the United States, there are approximately 240,000 water main pipe breaks each year. To help estimate pipe breaks and maintenance frequency, a number of physically-based and statistically-based water main failure prediction models have been developed in the last 30 years. Precious review papers focused more on the evolution of failure models rather than modeling results. However, the modeling results of different models applied in case studies are worth reviewing as well.

In this review, we focus on research papers after Year 2008 and collect latest cases without repetition. …

Airport Security Investment Model, Joshua Daniel Bolton

Graduate Theses and Dissertations

In an increasingly mobile and diverse world, it is difficult to quantify the risk, or danger, associated with traveling. Airports have suffered greatly for being unable to define potential risks and protect against them. Intelligent adversary risk is a complicated high-level issue for many airports. Airports are targeted because of the large amount of people in a confined space and the social, economic, and psychological impact of terrorist attacks on the American people. In the months following September 11th, 2001, the airline industry in the United States lost $1.1 billion in revenue. The American people stayed grounded, for fear of …

Analyzing The Fundamental Aspects And Developing A Forecasting Model To Enhance The Student Admission And Enrollment System Of Msom Program, Sultanul Nahian Hasnat

Graduate Theses and Dissertations

A forecasting model, associated with predictive analysis, is an elementary requirement for academic leaders to plan course requirements. The M.S. in Operations Management (MSOM) program at the University of Arkansas desires to understand future student enrollment more accurately. The available literature shows that there is an absence of forecasting models based on quantitative, qualitative and predictive analysis. This study develops a combined forecasting model focusing on three admission stages. The research uses simple regression, Delphi analysis, Analysis of Variance (ANOVA), and classification tree system to develop the models. It predicts that 272, 173, and 136 new students will apply, matriculate …

Methodologies For Solving Integrated Transportation And Scheduling Problems, Fereydoun Adbesh

Graduate Theses and Dissertations

This research proposes novel solution techniques to optimize two real-world problems in the area of scheduling and transportation. We first consider a model for optimizing the operations of dredges. In this problem, scheduling and assignment decisions are integrated across a finite planning horizon. Additional constraints and problem elements explicitly considered include, but are not limited, to environmental work window restrictions, budget limitations, dredge operation rates and schedule-dependent dredge availability. Our approach makes use of Constraint Programming (CP) to obtain quality and robust solutions within an amount of time small enough to be useful to practitioners. The expanded feature set of …

Essays In Measuring, Controlling, And Coordinating Supply Chain Inventory And Transportation Operations, Payam Parsa

Graduate Theses and Dissertations

Supply chain collaboration programs, such as continuous replenishment program (CRP), is among the most popular supply chain management practices. CRP is an arrangement between two partners in a supply chain to share information on a regular basis for lowering logistics costs while maintaining or increasing service levels. CRP shifts the replenishment responsibility to the upstream partner to avoid the bullwhip effect across the supply chain. This dissertation aims to quantify, measure, and expand the benefits of CRP for the purpose of reducing logistics cost and improving customer service. The developed models in this dissertation are all applied in different case …

An Economic Analysis Of Residential Photovoltaic Systems With And Without Energy Storage, Rodney Moses Kizito

Graduate Theses and Dissertations

Residential photovoltaic (PV) systems serve as a source of electricity generation that is separate from the traditional utilities. Investor investment into residential PV systems provides several financial benefits such as federal tax credit incentives for installation, net metering credit from excess generated electricity added back to the grid, and savings in price per kilowatt-hour (kWh) from the PV system generation versus the increasing conventional utility price per kWh. As much benefit as stand-alone PV systems present, the incorporation of energy storage yields even greater benefits. Energy storage (ES) is capable of storing unused PV provided energy from daytime periods of …

Decision Support System For Container Port Selection Using Multiple-Objective Decision Analysis, Rivelino De Icaza

Graduate Theses and Dissertations

Ports are essential for maritime transportation and global supply chains since they are nodes that connect the sea- and land-based modes of transportation. With containerization and supply chains stimulating global trade, ports are challenged to adjust to changes in the market to create value to their customers. Therefore, this dissertation research focuses on the container port selection decision analysis to provide information to help shipping lines select the best port for their shipping networks. Since the problem is complex, dynamic, and involves multiple and conflicting criteria, the research proposes to use the multi-objective decision analysis with Value-Focused Thinking approach. The …

Models And Methodologies To Address Emerging Needs In Network And Supply Chain Optimization, Forough Enayaty Ahangar

Graduate Theses and Dissertations

In this dissertation, we model three different security scenarios and propose solution methodologies to address each problem.

Chapter 2 presents a large-scale optimization approach for solving a dynamic bi-level network interdiction problem (NIP) in which interdiction activities must be scheduled in order to minimize the cumulative maximum flow over a finite time horizon. A logic-based decomposition (LBD) approach is proposed that utilizes constraint programming to exploit the scheduling nature of this dynamic NIP. Chapter 3 considers a set of centers to which content (e.g., data or smuggled items), are assigned to ensure availability. An interdictor (e.g., border security officials) attempts …

Personalized Decision Modeling For Intervention And Prevention Of Cancers, Fan Wang

Graduate Theses and Dissertations

Personalized medicine has been utilized in all stages of cancer care in recent years, including the prevention, diagnosis, treatment and follow-up. Since prevention and early intervention are particularly crucial in reducing cancer mortalities, personalizing the corresponding strategies and decisions so as to provide the most appropriate or optimal medical services for different patients can greatly improve the current cancer control practices. This dissertation research performs an in-depth exploration of personalized decision modeling of cancer intervention and prevention problems. We investigate the patient-specific screening and vaccination strategies for breast cancer and the cancers related to human papillomavirus (HPV), representatively. Three popular …

Simulation Modeling Approach For Evaluating A Solution Designed To Alleviate The Congestion Of Passenger Flow At The Composure Area Of Security Checkpoints, Maria Luisa Janer Rubio

Graduate Theses and Dissertations

In a previous study, we found that replacing the exit roller of a security checkpoint lane for a continuously circulating conveyor could potentially increase the throughput of passengers by over 28% while maintaining the TSA security-waiting time limit (Janer and Rossetti 2016). This study intends to expand this previous effort by investigating the impact of this circulating conveyor on the secondary screening related processes. Leone and Liu (2011) found that imposing a limit on the x-ray screening time, and diverting any item exceeding this limit to secondary screening, could decrease the waiting time by 43%. Our objective is to verify …

Is It We Or They? The Effect Of Identity On Collaboration And Performance In Buyer-Supplier Relationships, Siqi Ma

Graduate Theses and Dissertations

In today’s scale-driven and technology-intensive global economy, collaboration becomes the supply chain’s core capability (Liker and Choi, 2004). A well-developed ability to create and sustain fruitful collaborations gives companies a significant competitive advantage (Kanter, 1994). Retailers are increasingly relying on their suppliers to reduce costs, improve quality, and develop new processes and products faster than their rivals’ vendors can. On the other hand, suppliers benefit from retailers that they are able to monitor store-level demand in real time in order to ensure the top-selling items are in-stock or the accuracy and timeliness of retailer’s demand forecast. Previous literature has shown …

Service Consistency In Vehicle Routing, Kunlei Lian

Graduate Theses and Dissertations

This thesis studies service consistency in the context of multi-period vehicle routing problems (VRP) in which customers require repeatable services over a planning horizon of multiple days. Two types of service consistency are considered, namely, driver consistency and time consistency. Driver consistency refers to using the fewest number of different drivers to perform all of the visits required by a customer over a planning horizon and time consistency refers to visiting a customer at roughly the same time on each day he/she needs service. First, the multi-objective consistent VRP is defined to explore the trade-offs between the objectives of travel …

The Effect Of Process Parameters And Surface Condition On Bond Strength Between Additively Manufactured Components And Polymer Substrates, Bharat Bhushan Chivukula

Graduate Theses and Dissertations

Additive patching is a process in which printers with multiple axes deposit molten material onto a pre-defined surface to form a bond. Studying the effect of surface roughness and process parameters selected for printing auxiliary part on the bond helps in improving the strength of the final component. Particularly, the influence of surface roughness, as established by adhesion theory, has not been evaluated in the framework of additive manufacturing (AM). A full factorial design of experiments with five replications was conducted on two levels and three factors, viz., layer thickness, surface roughness, and raster angle to examine the underlying effects …

Safety Performance Prediction Of Large-Truck Drivers In The Transportation Industry, Emily Moneka Francis Xavier

Graduate Theses and Dissertations

The trucking industry and truck drivers play a key role in the United States commercial transportation sector. Accidents involving large trucks is one such big event that can cause huge problems to the driver, company, customer and other road users causing property damage and loss of life. The objective of this research is to concentrate on an individual transportation company and use their historical data to build models based on statistical and machine learning methods to predict accidents. The focus is to build models that has high accuracy and correctly predicts an accident. Logistic regression and penalized logistic regression models …

Grouping Techniques To Manage Large-Scale Multi-Item Multi-Echelon Inventory Systems, Anvar Abaydulla

Graduate Theses and Dissertations

Large retail companies operate large-scale systems which may consist of thousands of stores. These retail stores and their suppliers, such as warehouses and manufacturers, form a large-scale multi-item multi-echelon inventory supply network. Operations of this kind of inventory system require a large number of human resources, computing capacity, etc.

In this research, three kinds of grouping techniques are investigated to make the large-scale inventory system “easier” to manage. The first grouping technique is a network based ABC classification method. A new classification criterion is developed so that the inventory network characteristics are included in the classification process, and this criterion …

Essays On Optimization And Modeling Methods For Reliability And Reliability Growth, Thomas Paul Talafuse

Graduate Theses and Dissertations

This research proposes novel solution techniques in the realm of reliability and reliability growth. We first consider a redundancy allocation problem to design a system that maximizes the reliability of a complex series-parallel system comprised of components with deterministic reliability. We propose a new meta-heuristic, inspired by the behavior of bats hunting prey, to find component allocation and redundancy levels that provide optimal or near-optimal system reliability levels. Each component alternative has an associated cost and weight and the system is constrained by cost and weight factors. We allow for component mixing within a subsystem, with a pre-defined maximum level …

Incorporating A New Class Of Uncertainty In Disaster Relief Logistics Planning, Emre Kirac

Graduate Theses and Dissertations

In recent years, there has been a growing interest among emergency managers in using Social data in disaster response planning. However, the trustworthiness and reliability of posted information are two of the most significant concerns, because much of the user-generated data is initially not verified. Therefore, a key tradeoff exists for emergency managers when considering whether to incorporate Social data in disaster planning efforts. By considering Social data, a larger number of needs can be identified in a shorter amount of time, potentially enabling a faster response and satisfying a class of demand that might not otherwise be discovered. However, …

Essays In Physicians Preference Items And Inventory Management Within The Healthcare Supply Chain, Mohammad A. Shbool

Graduate Theses and Dissertations

This work is composed of a number of topics in the healthcare area, which are approached separately with appropriate methodologies. The two topics deal with physician preference items via two different approaches. The first one investigates stock keeping unit (SKU) proliferation in healthcare organizations due to physician preference items (PPI). It captures perspectives of physicians and supply chain professionals about this problem through two surveys. The second topic builds a decision-making framework for the PPI selection process that can be used by healthcare organizations to make more objective decisions. A Multi-criteria decision making technique is implemented to illustrate the framework.

A Tabu Search, Augment-Merge Heuristic To Solve The Stochastic Location Arc Routing Problem, Tiffany L. Yang

Graduate Theses and Dissertations

The location arc routing problem (LARP) is a network optimization problem combining strategic facility location decisions and tactical or operational vehicle routing decisions for customer demand located on arcs of a network. The LARP seeks to locate facilities, or depots, and create vehicle delivery routes to minimize costs. The total cost is comprised of three components: fixed facility locations costs, fixed route creation (or vehicle acquisition) costs, and variable arc traversal costs. The applications of the LARP are varied and often include public services such as mail delivery, garbage collection, and street sweeping. In all of these applications, the magnitude …

Risk Estimation Toward A Natural History Model For Low Grade Glioma Patients, Anh Thi Hoang Pham

Graduate Theses and Dissertations

Glioma is a common type of primary brain tumor that represents 28% of all brain tumors and 80% of malignant tumors. According to a recent study by the Centers for Disease Control and Prevention (CDC), gliomas account for 53%, 35% and 29% of all brain tumors (68%, 74% and 81% of malignant brain tumors) among children (aged 0-14), teenagers (aged 15-19) and young adults, respectively. Gliomas are often diagnosed through radiological imaging and histopathology. There are two main groups of gliomas following World Health Organization’s classification: Low grade gliomas (LGG), or grade I and II gliomas; and high grade gliomas …

Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong

Graduate Theses and Dissertations

In designing accelerated testing plans, cost is a factor that is missing in much of the literature. This paper explicits considers cost by developing an optimization model with the objective to minimize costs for a simple step stress accelerated test plan. Two methodologies are employed. One is an optimization approach in which an attempt is made to quantify the behavior of a series-parallel hardware system over all stages of testing using a response surface, and then an optimization model is used to determine the settings for stresses and failure mode modifications for all stages of testing prior to the start …

Preventive Maintenance Decision Modeling In Health And Service Systems, Mahboubeh Madadi

Graduate Theses and Dissertations

This dissertation focuses on the preventive maintenance decision modeling in healthcare and service systems. In the first part of this dissertation, some issues in preventive health decisions for breast cancer are addressed, and in the second part, the required characteristics for preventive maintenance of an unreliable queuing system are derived.

Adherence to cancer screening is the first issue that is addressed in this dissertation. Women’s adherence or compliance with mammography screening remained low in the recent years. In this dissertation, we first develop a design-based logistic regression model to quantify the probability of adherence to screening schedules based on women’s …

Understanding Technology Diffusion And Spatial Accessibility In The Home Healthcare Industry, Mehmet Serdar Kilinç

Graduate Theses and Dissertations

Home healthcare is becoming an important alternative to institutionalized care. It not only reduces costs but also increases health outcomes and patient satisfaction. However, the availability and efficiency of home healthcare services need to be improved as the aging population increases in the US. Hence, understanding home healthcare utilization and access are the essential steps to develop strategies ensuring effective and sustainable services to patients.

This research aims to study two main issues in the US home healthcare system: diffusion and long-term impacts of home telehealth and potential spatial accessibility of home healthcare services. Home telehealth is a promising technology …

An Adaptive Large Neighborhood Search Heuristic For The Inventory Routing Problem With Time Windows, Mina Hadianniasar

Graduate Theses and Dissertations

This research addresses an integrated distribution and inventory control problem which is faced by a large retail chain in the United States. In their current distribution network, a direct shipping policy is used to keep stores stocked with products. The shipping policy specifies that a dedicated trailer should be sent from the warehouse to a store when the trailer is full or after five business days, whichever comes first. Stores can only receive deliveries during a window of time (6 am to 6 pm). The retail chain is seeking more efficient alternatives to this policy, as measured by total transportation, …

Creating Quality Metrics For The Capital Facilities Delivery Industry, Kelsey D. Lamb

Graduate Theses and Dissertations

A standard for industry-wide quality metrics, similar to safety metrics, for the capital facilities delivery industry is investigated and developed with the goal to motivate industry-wide adoption of this new quality metric program. A survey of the literature found key differences between capital facilities and other industries, mainly that other industries focus on the quality of the product while capital facilities focus on maintaining the cost and schedule of a project. Creating a framework that can be used across the industry can potentially lead to uniform improvement of quality for the entire industry. Quality is defined for the capital facilities …