Operations Research, Systems Engineering and Industrial Engineering Commons^™

An Exploratory Study Of Mixed-Width Aisle Layouts For Order Picking In Distribution Centers, Corinne H. Mowrey

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Order picking is arguably the most expensive operational activity for a distribution center (DC), constituting upwards of 50% of total operating costs. Designing an optimum order picking system (OPS) for a DC depends on several system parameters, such as aisle layout, storage system configuration, storage policy, picking method, and picking strategy. From an aisle layout standpoint, traditional DCs utilize either entirely wide or entirely narrow aisles in their picking systems. Wide aisles allow pickers to pass each other, reducing blocking and requiring fewer pickers. However, the space required for wide-aisle systems is high. Narrow aisles utilize less space than wide …

Drop-Shipping At A Promotional Products Distributor, Ramanan Veeraragavan

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During the current economic times, companies are trying to reduce costs by incorporating new strategies into their business plan. Supply chain, in particular the distribution network is one area where an improvement can bring in a healthy return on investment to a company. Drop-shipping is a distribution strategy whereby customer orders are fulfilled by directly delivering products from manufacturer's facility, instead of storing these products at the warehouse. Drop-shipping helps in reducing inventory and material handling costs at the warehouse, but may increase transportation costs due to frequent shipments. This research was motivated by the current operations at a promotional …

Scheduling Surgical Cases In A Constrained Environment, Bharathwaj Vijayakumar

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This research examines a complex surgical case scheduling problem for a publicly-funded hospital in the Midwest United States. Publicly-funded hospitals are typically under tight budget constraints and these hospitals strive to maximize the utilization of their resources such as beds, staff, equipment, operating rooms, etc. These resources are relatively fixed for a publically funded hospital. A manual scheduling approach followed by this hospital does not guarantee optimal solutions and consequently has led to large variation in the utilization of resources. This real-world problem is described in this research as a multi-day, multi-resource, and patient-priority-based surgical case scheduling problem with the …

Determining The Optimal Aisle-Width For Order Picking In Distribution Centers, Sheena R. Wallace-Finney

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Many companies use distribution centers (DC) as hubs for storing and distributing products to customers (e.g., wholesalers, retailers, or consumers). Order picking, a critical activity in every DC, refers to retrieving products from the storage locations to fulfill customer orders. It accounts for over 50% of the DC operating cost. Order picking system design involves several decisions, such as layout of the picking area, storage policy, picking method, material handling equipment, and information technology, to name a few. Aisle configuration (number, length, width, and orientation) is a critical layout decision as it directly affects picker productivity and required space. Previous …

Developing A Time And Motion Study For A Lean Healthcare Environment, Michael Winston Patton Jr.

University of Kentucky Master's Theses

This thesis outlines the development of a standard methodology for performing a time and motion study in a lean healthcare environment. Time and motion studies have been used in healthcare environments in the past, however they have nearly all been exclusive to a particular healthcare enterprise. To develop the time and motion study methodology, a study was designed to examine how resident doctors spend their time. This study was performed in response to coming changes in the work hours for all residents. Once the methodology was developed, trial observations were conducted. The data from these observations was analyzed to determine …

Improving Throughput And Predictability Of High-Volume Business Processes Through Embedded Modeling, Joseph S. Dekeyrel

Electronic Theses and Dissertations

Being faster is good. Being predictable is better. A faithful model of a system, loaded to reflect the system's current state, can then be used to look into the future and predict performance. Building faithful models of processes with high degrees of uncertainty can be very challenging, especially where this uncertainty exists in terms of processing times, queuing behavior and re-work rates. Within the context of an electronic, multi-tiered workflow management system (WFMS) the author builds such a model to endogenously quote due dates. A WFMS that manages business objects can be recast as a flexible flow shop in which …

Models For Evaluation Of Supply Chain Risk With Application To Healthcare Management, Ford Guangfu Zeng

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Over the past two decades, supply chain management has come to be a key component of organization competitiveness and effectiveness. In the same period, most organizations have put a great deal of effort into improving their own and their supplier's supply chain performance. To a large extent, much of this effort has been aimed at improving the efficiency of supply chain operations. However, organizations have ignored or played down the risks from supply chain disruptions when developing supply strategies, which focus on cost reduction. It is proposed, therefore, that one such standard measure should measure the risk involved with organizations …

Mathematical Optimization Techniques For Managing Selective Catalytic Reduction For Coal-Fired Power Plants, Passakorn Phananiramai

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Coal is one of the most important energy sources in the U.S. However, it is also one of the biggest air polluters where the major emissions generated from coal combustion are oxides of nitrogen (NOx). NOx leads to ozone formation and make people more susceptible to respiratory illness. The US Environmental Protection Agency (EPA) has steadily tightened the regulation for NOx emissions that can be discharged into the atmosphere. Many techniques and technologies can all assist with NOx removal. However, to meet upcoming EPA mandates, more aggressive technique such as Selective Catalytic Reduction (SCR) is highly recommended. SCR is an …

Life Cycle Inventory Of Hdpe Bottle-Based Liquid Milk Packaging Systems, Jay Singh, Aric Krasowski, S. Paul Singh

Industrial Technology and Packaging

This study aims at providing a relatively straightforward methodology to serve as a decision-making tool when more than one packaging solution could be available to a user. It involves a life cycle inventory (LCI) analysis and comparison of three currently available 3.79 l (1 gallon) packaging systems for liquid milk. Two of the primary container types studied use reusable plastic crates (RPCs) for stacking and shipping,
while the third type is a heavier duty container that does not require secondary shipping containers. The three primary containers studied are identified as original, cube and stackable throughout this paper. The study shows …

A Multiple Performance Analysis Of Market-Capacity Integration Policies, Ahmed M. Deif, Hoda A. Elmaraghy

Industrial Technology and Packaging

A model that uses simulation augmented with Design of Experiments (DOE) is presented to analyse the performance of a Make-to-Order (MTO) reconfigurable manufacturing system with scalable capacity. Unlike the classical capacity scaling policies, the proposed hybrid capacity scaling policy is determined using multiple performance measures that reflect cost, internal stability and responsiveness. The impact of both tactical capacity and marketing policies and their interaction on the overall performance was analysed using DOE techniques and real case data. In addition to the different insights about the trade-offs involved in capacity planning decisions, the presented results challenged the conventional capacity planning wisdoms …

A Study To Determine The Influence Of Workload On Nursing Personnel, Supreeta G. Amin

Dissertations

The alarming number of adverse medical events and associated costs have placed immense importance toward the safety and health of both patients and medical personnel. A shrinking nurse workforce, an aging patient and nursing population coupled with a mismatch between hospital demands and the available nursing staff have created a situation detrimental to both patient and nursing personnel. Long working hours, working more than one job, low staffing ratios, high patient acuity, minimal social support, low experience level, complicated equipment, complex procedures and varying workload are some factors that may have a negative impact on the quality of care provided …

Benefits Of Cpfr And Vmi Collaboration Strategies In A Variable Demand Environment, Dattaraj Kamalapurkar

Dissertations

In recent years, practitioners and academic researchers have emphasized that organizations need to collaborate with suppliers and customers to improve their competitive advantage. The availability of cost efficient information technologies like EDI, XML, etc. have made it possible to develop and implement many forms of collaboration strategies. Among them, Vendor Managed Inventory (VMI) and Collaborative Planning, Forecasting and Replenishment (CPFR) are most popular, which are considered for this study. While many studies have identified the benefits of demand information sharing in supply chains; however the benefits gained by implementing collaboration strategies like VMI and CPFR in a variable demand environment …

Virtual Design Verification And Process Improvement Of Composite Sheet Material Products Using Intelligent Finite Element Analysis (Ifea), Sathyanarayanan Narasimhan

Dissertations

Engineering design decisions influence more than 70% of product costs. Various computational analysis tools such as Finite Element Analysis (FEA) are typically utilized, to achieve an effective design cycle. Literature review in design process indicates a striking reality that about 75% of design errors can be eliminated through analysis and about 20% of analyses are misrepresented, leading to inadequate or faulty design. Also, analyses in general, generate more information about the problem than is often looked into, leading to a vast potential to study the knowledge creation.

This research bridges these gaps in design process through efficient use of computer-based …

Assessing System Architectures: The Canonical Decomposition Fuzzy Comparative Methodology, Jason Paul Dauby

Doctoral Dissertations

"The impacts of decisions made during the selection of the system architecture propagate throughout the entire system lifecycle. The challenge for system architects is to perform a realistic assessment of an inherently ambiguous system concept. Subject matter expert interpretations, intuition, and heuristics are performed quickly and guide system development in the right overall direction, but these methods are subjective and unrepeatable. Traditional analytical assessments dismiss complexity in a system by assuming severability between system components and are intolerant of ambiguity. To be defensible, a suitable methodology must be repeatable, analytically rigorous, and yet tolerant of ambiguity. The hypothesis for this …

Exploratory Study Of Barriers To Use Of Feigenbaum's Quality Cost Strategy Within Design Engineering Firms, David Patrick Loduca

Doctoral Dissertations

"It has been more than a half century since Armand Feigenbaum first conceived of the strategy for the manufacturing sector, yet quality costing strategies have not found a foothold among engineering firms. This study was aimed at constructing a set of theories that explains possible barriers to acceptance of the Feigenbaum strategy by analyzing attitudes and opinions of players in an actual engineering firm and the culture in which they work.

Modeled after the Feigenbaum approach and tailored to the business model of engineering and architectural firms, a system was developed to classify and record costs of quality. A local …

The Impact Of Supply Chain And Network Structure On The Environmental Performance Of Sustainability-Focused Companies, Ozan Ozcan

USF Tampa Graduate Theses and Dissertations

The goal of this dissertation was to contribute to our understanding of the relationship between supply chain structure and the pursuit of a sustainability-driven corporate strategy. The literature indicates that in order to pursue a sustainability-focused strategy, an increased level of integration across the supply chain is required. However, there are also industry-level dynamics that impact observed levels of vertical integration. That is, some industries are naturally more integrated than others based on the maturity level of the industry. Thus, some firms may experience opposing forces regarding their sourcing strategies once they choose to pursue a sustainability-focused strategy.

To explore …

Apparent Total Evaporative Resistance Values From Human Trials Over A Range Of Metabolic And Heat Stress Levels, Matthew David Dooris

USF Tampa Graduate Theses and Dissertations

Failure to maintain thermal equilibrium can cause uncontrollable increases in body core temperature beyond critical upper limits. In selecting clothing, consideration must be given to the heat transfer properties of clothing that may restrict the cooling capacity of the human body under heat stress conditions, most importantly, apparent total evaporative resistance (R_e,T,_a). This study calculated and compared R_e,T,_a for five clothing ensembles under varying heat stress conditions, including three relative humidity (RH) levels and three stages of heat stress to determine if R_e,T,_a values varied or remained the same with …

Decision Aid Models For Resource Sharing Strategies During Global Influenza Pandemics, Alfredo Santana Reynoso

USF Tampa Graduate Theses and Dissertations

Pandemic influenza outbreaks have historically entailed significant societal and economic disruptions. Today, our quality of life is threatened by our inadequate preparedness for the imminent pandemic. The key challenges we are facing stem from a significant uncertainty in virus epidemiology, limited response resources, inadequate international collaboration, and the lack of appropriate science-based decision support tools. The existing literature falls short of comprehensive models for global pandemic spread and mitigation which incorporate the heterogeneity of the world regions and realistic travel networks. In addition, there exist virtually no studies which quantify the impact of resource sharing strategies among multiple countries. This …

Identification Of Patient Recovery Patterns After Cardiovascular Surgery Based On Laboratory Tests Results, Alcides Ricardo Santander Mercado

USF Tampa Graduate Theses and Dissertations

In this dissertation is proposed a methodology to identify patient's recovery patterns after cardiovascular surgery based on laboratory tests results. The main purpose is to enhance the understanding of the manifestations of postsurgical complications in patients who underwent cardiovascular surgery. The analysis of patients' recovery process is based on the relationship between plasma calcium, ionized calcium and platelet count over time.

Laboratory results from the James A. Haley Veterans' Hospital databases, related to patients admitted to the Surgical Intensive Care Unit (SICU) after cardiac surgery (coronary artery bypass, aortic value replacement and mitral valve replacement), are used. These databases contain …

Decision Support Models For Design Of Fortified Distribution Networks, Qingwei Li

USF Tampa Graduate Theses and Dissertations

Lean distribution networks have been facing an increased exposure to the risk of unpredicted disruptions causing significant economic forfeitures. At the same time, the existing literature contains very few studies that examine the impact of fortification of facilities for improving network reliability. This dissertation presents three related classes of models that support the design of reliable distribution networks. The models extend the uncapacitated P-median and fixed-charge location models by considering heterogeneous facility failure probabilities, supplier backups, and facility fortification within a finite budget. The first class of models considers binary fortification via linear fortification functions. The second class of models …

The Impact Of Pharmacy Work Design On Pharmacist Productivity, Nicholas Allen Coblio

USF Tampa Graduate Theses and Dissertations

Healthcare costs in the United States continue to grow at an alarming rate. Concerning the cost of medications, there are a number of factors that drive these costs. While personnel costs are not the largest of these, they do contribute a significant portion. The cost of the cognitive component of order processing by pharmacists can range from three dollars to over six dollars per prescription depending on the production throughput of the pharmacist.

Studies at the organization which was the focus of the research, as well as reports in the literature, indicated that work disruption and other environmental factors could …

Analytical Methods To Support Risk Identification And Analysis In Healthcare Systems, Laila Nadime Cure Vellojin

USF Tampa Graduate Theses and Dissertations

Healthcare systems require continuous monitoring of risk to prevent adverse events. Risk analysis is a time consuming activity that depends on the background of analysts and available data. Patient safety data is often incomplete and biased. This research proposes systematic approaches to monitor risk in healthcare using available patient safety data. The methodologies combine traditional healthcare risk analysis methods with safety theory concepts, in an innovative manner, to allocate available evidence to potential risk sources throughout the system. We propose the use of data mining to analyze near-miss reports and guide the identification of risk sources. In addition, we propose …

Instance-Based Parameter Tuning Via Search Trajectory Similarity Clustering, Linda Lindawati, Hoong Chuin Lau, David Lo

Research Collection School Of Computing and Information Systems

This paper is concerned with automated tuning of parameters in local-search based meta-heuristics. Several generic approaches have been introduced in the literature that returns a ”one-size-fits-all” parameter configuration for all instances. This is unsatisfactory since different instances may require the algorithm to use very different parameter configurations in order to find good solutions. There have been approaches that perform instance-based automated tuning, but they are usually problem-specific. In this paper, we propose CluPaTra, a generic (problem-independent) approach to perform parameter tuning, based on CLUstering instances with similar PAtterns according to their search TRAjectories. We propose representing a search trajectory as …

Improving Service Through Just-In-Time Concept In A Dynamic Operational Environment, Kar Way Tan, Hoong Chuin Lau, Na Fu

Research Collection School Of Computing and Information Systems

This paper is concerned with the problem of Just-In-Time (JIT) job scheduling in a dynamic environment under uncertainty to attain timely service. We provide an approach, based on robust scheduling concepts, to analytically evaluate the expected cost of earliness and tardiness for each job and also the project. In addition, we search for a schedule execution policy with the minimum robust cost such that for a given risk level (epsilon), the actual realized schedule has (1 - epsilon) probability of completing with less than or equal to this robust cost. Our method is quite generic, and can be applied to …

Fine-Tuning Algorithm Parameters Using The Design Of Experiments Approach, Aldy Gunawan, Hoong Chuin Lau, Linda Lindawati

Research Collection School Of Computing and Information Systems

Optimizing parameter settings is an important task in algorithm design. Several automated parameter tuning procedures/configurators have been proposed in the literature, most of which work effectively when given a good initial range for the parameter values. In the Design of Experiments (DOE), a good initial range is known to lead to an optimum parameter setting. In this paper, we present a framework based on DOE to find a good initial range of parameter values for automated tuning. We use a factorial experiment design to first screen and rank all the parameters thereby allowing us to then focus on the parameter …