Operational Research Commons^™

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 …

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 …

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 …

A Quantitative Model For Truck Parking Utilization With Hours Of Service Regulations, Alexis Christine Gaddy

Industrial Engineering Undergraduate Honors Theses

Continual growth in traffic volume on U.S. Highways and insufficient parking for commercial trucking vehicles has led to significant safety concerns for truck drivers. Hours of Service (HOS) regulations dictate driving and rest periods of truck drivers. When a truck driver must stop as designated by the HOS regulations and the nearest parking location is at capacity, the trucker must either continue driving past the HOS limit or park in an undesignated and possibly illegal or unsafe spot such as an off-ramp. The combination of these two variables play an important role in the safety of truck drivers on a …

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 …

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 …

Using Value-Focused Thinking For Engineered Resilient Systems, Colin A. Small

Industrial Engineering Undergraduate Honors Theses

The DoD needs their systems to be resilient in the face of an ever changing world. To increase resilience in future systems the DoD has created a program called Engineered Resilient Systems. Resilience can be broken down into two parts, mission and platform resilience. Mission resilience is the ability of a system to repel, resist, absorb, and recover from environments and threats that occur on planned missions. Platform resilience is the ability of a system platform to adapt to new missions and new threats.

The University of Arkansas department of Industrial Engineering is working for the ERS program researching resilience. …

Modeling Supply Chain Resiliency, Jeff A. Hazel

Industrial Engineering Undergraduate Honors Theses

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of complex engineered systems throughout their life cycle. There is a growing literature with qualitative definitions of resilience and quantitative models for systems with one performance measure. This paper uses a quantitative resilience framework (the Framework for ERS) that includes system design options, reliability, threats, vulnerabilities, responses, and consequences assessed in multiple system performance measures. The framework assists in establishing a model for any system to evaluate resiliency. This paper applies this framework using Multiple Objective Decision Analysis (MODA) to …

Engineered Resilient Systems Model Applied To Network Design, Zephan W. Wade

Industrial Engineering Undergraduate Honors Theses

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of resilient complex engineered systems throughout their lifecycle. There is growing literature with qualitative definitions of resilience and quantitative models for systems, but these focus typically on systems with one performance measure. In application, many systems have multiple functions and multiple performance measures. This research uses a quantitative resilience framework for ERS that includes system design options, reliability, external threats, vulnerabilities, responses, and consequences assessed on multiple system performance measures. This paper applies the ERS framework to designing resilient networks.

Baseball Portfolio Optimization, Keegan Henderson

Industrial Engineering Undergraduate Honors Theses

Portfolio optimization techniques are methods used to determine the best set of stocks in which to invest. Mean-variance optimization, one method of portfolio optimization, attempts to find the set of portfolios that have the maximum expected return at each level of risk (Jorion, 1992). Another technique, Monte Carlo simulation, uses random number generation to create a probability distribution of potential returns (Kwak & Ingall, 2007). This can be used to determine the risk of potential investments not returning a certain desired amount (Thompson & McLeod, 2009). Though traditionally used in the world of finance, these tools can also be utilized …

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 …

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 …

Modeling Information Reliability And Maintenance: A Systematic Literature Review, Daysi A. Guerra Garcia

Industrial Engineering Undergraduate Honors Theses

Operating a business efficiently depends on effective everyday decision-making. In turn, those decisions are influenced by the quality of data used in the decision-making process, and maintaining good data quality becomes more challenging as a business expands. Protecting the quality of the data and the information it generates is a challenge faced by many companies across all industrial sectors. As companies begin to use data from these large data bases they will need to begin to develop strategies for maintaining and assessing the reliability of the information they generate using this data. A considerable amount of literature exists on data …

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 …

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, …

Analysis Of Portable Charging Systems For Mobile Devices Utilizing Today's Technology, Dylan Ashley

Electrical Engineering Undergraduate Honors Theses

With the progression of technological advances, electronic devices are becoming increasingly smaller while simultaneously becoming increasing powerful. Consumer demand for a cheaper, longer lasting battery life challenges today’s engineers to continually develop a battery and its circuitry with increasing efficiency without compromising performance. Developing an affordable, efficient external battery pack has been the marketable solution, but the question is whether or not the existing external battery packs available are meeting the wants and desires of the end consumer. The answer is partially in that my research confirms that the current solution is not ideal; however, efficiency has been increased as …

Maritime Transportation Research Bank, Valeria A. Remon Perez

Industrial Engineering Undergraduate Honors Theses

The maritime transportation system is an important component of the United States’ (U.S.) economy, from commerce activities to freight movement to disaster’ relief. The annual impact of the maritime transportation system on the U.S. national economy is reported as approximately $649 billion of the total U.S. gross domestic product (U.S. Department of Transportation Maritime Administration, n.d.). This impact is attributed to activities related to the movement of goods and people. Indeed, the maritime transportation system plays an important role in international trade by transporting goods such as coal and farm products, which are common commodities for foreign and domestic commerce …

Inventory Management And Control "For A Cause", John Michael Miller

Graduate Theses and Dissertations

Companies today are changing the culture of business and beginning to involve more than just labor and money in overall decisions. Just as sustainability issues and humanitarian logistics are gaining popularity, so is the idea of using business to make a difference on society in addition to making a profit. As companies position themselves across the globe to make an impact, they employ people in third-world environments that create uncertainties on both the supply and demand sides. Also, the idea of strategically planning work with the goal of minimizing costs has been replaced by companies wanting to give more work …

Using The Triple Bottom Line To Select Sustainable Suppliers For A Major Oil And Gas Company, Pandarinath Adarsh Sunkari

Graduate Theses and Dissertations

Companies have primarily been focusing on the financial bottom line i.e., on increasing profits by increasing revenues and reducing costs. With high energy usage and environmental change posing threats to the environment and business operations, companies are now considering sustainability. Since some global suppliers have low cost labor, Social well-being and human development has also emerged as major goals of a company performing global operations. Focusing on these three goals is termed the "Triple Bottom Line" (TBL). We study and explore the TBL benefits that could be realized by an oil and gas company by focusing on sustainable suppliers. A …

Modeling Expected Travel Distances For A Common Warehouse Design With Multiple Docks, Mahmut Tutam

Graduate Theses and Dissertations

This thesis develops expected travel distance expressions for both single- and dual-command operations in a unit-load warehouse design with multiple docks. Storage racks are aligned perpendicular to the wall containing docks. Results are presented for continuous and discrete formulations. Because of the importance of how docks are located on a wall, different dock locations are investigated, including uniformly distributed docks along one wall, specified distances between adjacent docks located symmetrically about the mid-point of a warehouse wall, and any distribution of locations along one wall. Among the results obtained, we find that the width-to-depth ratio of the storage area (commonly …

Truckload Shipment Planning And Procurement, Neo Nguyen

Graduate Theses and Dissertations

This dissertation presents three issues encountered by a shipper in the context of truckload transportation. In all of the studies, we utilize optimization techniques to model and solve the problems. Each study is inspired from the real world and much of the data used in the experiments is real data or representative of real data.

The first topic is about the freight consolidation in truckload transportation. We integrate it with a purchase incentive program to increase truckload utilization and maximize profit. The second topic is about supporting decision making collaboration among departments of a manufacturer. It is a bi-objective optimization …

Strategic Planning Tool Development Using Portfolio Decision Analysis, Luis B. Vargas Rojas

Graduate Theses and Dissertations

A portfolio decision analysis strategic planning tool was developed for the Facilities Management Office at the University of Arkansas. The tool provides information to support budget allocation decisions based on their Strategic Planning Project List, project attributes (e.g, seat utilization, scheduling preferences, and sustainability rank), and budget constraints. The projects are evaluated using multiobjective decision analysis. We introduce dynamic value functions, which vary the range of the value measures based on the planning horizon, to evaluate the projects). We determine facilities portfolios based on the project values and constraints using Linear Programming. In addition, insightful reports are generated, which provide …

Large-Scale Solution Approaches For Healthcare And Supply Chain Scheduling, Ridvan Gedik

Graduate Theses and Dissertations

This research proposes novel solution techniques for two real world problems. We first consider a patient scheduling problem in a proton therapy facility with deterministic patient arrivals. In order to assess the impacts of several operational constraints, we propose single and multi-criteria linear programming models. In addition, we ensure that the strategic patient mix restrictions predetermined by the decision makers are also enforced within the planning horizon. We study the mathematical structures of the single criteria model with strict patient mix restrictions and derive analytical equations for the optimal solutions under several operational restrictions. These efforts lead to a set …

Robust Network Interdiction With Invisible Interdiction Assets, Nail Orkun Baycik

Graduate Theses and Dissertations

We study a version of the shortest path network interdiction problem in which the follower seeks to find the shortest path on a given network and the leader seeks to maximize the follower's shortest path length by interdicting arcs. We consider placement of interdictions that are not visible to the follower; however, we seek to locate interdictions in a manner that is robust against the possibility that some interdiction locations become known to the follower. We formulate the problem as a bi-level program, and use the simulated annealing heuristic to identify high quality solutions. We apply our approach to investigate …

Detailed Inventory Record Inaccuracy Analysis, Hayrettin Kaan Okyay

Graduate Theses and Dissertations

This dissertation performs a methodical analysis to understand the behavior of inventory record inaccuracy (IRI) when it is influenced by demand, supply and lead time uncertainty in both online and offline retail environment separately. Additionally, this study identifies the susceptibility of the inventory systems towards IRI due to conventional perfect data visibility assumptions. Two different alternatives for such methods are presented and analyzed; the IRI resistance and the error control methods. The discussed methods effectively countered various aspects of IRI; the IRI resistance method performs better on stock-out and lost sales, whereas error control method keeps lower inventory. Furthermore, this …

Cost Distribution Analysis Of Remote Monitoring System Use In The Treatment Of Chronic Diseases, Adeola Yusuf

Industrial Engineering Undergraduate Honors Theses

The cost of the treatment of chronic diseases is very high and this has a huge impact on the health-care system. Several factors contribute to this high cost. Some of these include the direct costs of treatment and the costs of several potential complications that arise as a result of the presence of other diseases. The goal of this study is to evaluate a cost-effective way of managing some of the common chronic diseases by analyzing the potential cost savings of utilizing remote monitoring systems (RMS) as opposed to the use of the traditional bundle (which includes regular visits to …

Surveillance Planning Against Smart Insurgents In Complex Terrain, Nabil Lehlou

Graduate Theses and Dissertations

This study is concerned with finding a way to solve a surveillance system allocation problem based on the need to consider intelligent insurgency that takes place in a complex geographical environment. Although this effort can be generalized to other situations, it is particularly geared towards protecting military outposts in foreign lands. The technological assets that are assumed available include stare-devices, such as tower-cameras and aerostats, as well as manned and unmanned aerial systems. Since acquiring these assets depends on the ability to control and monitor them on the target terrain, their operations on the geo-location of interest ought to be …

Decision Support Tool For Operations Management Course And Instructor Scheduling, Morgan Ulesich

Industrial Engineering Undergraduate Honors Theses

The goal of this project is develop a decision support tool that will assist the Operations Management Department at the University of Arkansas with scheduling courses and instructors for the upcoming academic year. The staff of the department dreads this time each year because it takes countless hours to complete the daunting task. Creating an abstract mathematical model will assist the department in scheduling the courses. The model will have the ability to optimize the schedule of the courses and instructors from a large number of variables and constraints that the department requires. An optimization software package can solve the …

Reliability Analysis Of Social Networks, Kellie R. Schneider

Graduate Theses and Dissertations

The primary focus of this dissertation is on the quantification of actor interaction and the dissemination of information through Social networks. Social networks have long been used to model the interactions between people in various Social and professional contexts. These networks allow for the explicit modeling of the complex interrelations between relevant individuals within an organization and the role they play in the decision making process. This dissertation considers Social networks represented as network flow models in which actors have the ability to provide some level of influence over other actors within the network. The models developed incorporate performance metrics …