Operations Research, Systems Engineering and Industrial Engineering Commons^™

Enhanced Load Balancing Based On Hybrid Artificial Bee Colony With Enhanced Β-Hill Climbing In Cloud, Maha Zeedan, Gamal Attiya, Nawal El-Fishawy

Mansoura Engineering Journal

This paper proposes enhanced load balancer based artificial bee colony and β-Hill climbing for improving the performance metrics such as response time, processing cost, and utilization to avoid overloaded or under loaded situations of virtual machines. In this study, the suggested load balancer is called enhanced load balancing based on hybrid artificial bee colony with enhanced β-Hill climbing (ELBABCEβHC) to improve the response time, processing cost and the resource utilization. Our proposed approach starts by ranking the task then the greedy randomized adaptive search procedure (GRASP) is used in initializing populations. Further, the binary artificial bee colony (BABC) enhanced with …

Essays On Perioperative Services Problems In Healthcare, Amogh S. Bhosekar

All Dissertations

One of the critical challenges in healthcare operations management is to efficiently utilize the expensive resources needed while maintaining the quality of care provided. Simulation and optimization methods can be effectively used to provide better healthcare services. This can be achieved by developing models to minimize patient waiting times, minimize healthcare supply chain and logistics costs, and maximize access. In this proposal, we study some of the important problems in healthcare operations management. More specifically, we focus on perioperative services and study scheduling of operating rooms (ORs) and management of necessary resources such as staff, equipment, and surgical instruments. We …

Optimal Scheduling Of Aircraft Test And Evaluation Fleets To Balance Availability For Testing And Training, Sarah E. Hoops

Theses and Dissertations

The 96th Test Wing at Eglin Air Force Base manually schedules a fleet of approximately 26 aircraft to conduct a range of missions over a one-to-two year planning period. This study automates the scheduling process, does so in a manner that optimizes multiple planning goals related to aircraft availability for training, and provides the 96th Test Wing with a software tool for the implementation that can be used by operational analysts within the command. We formulate the scheduling problem as a multiobjective, nonlinear, binary integer math program that seeks to maximize both the lowest percent of time any aircraft is …

A Study Of Scheduling Problems With Sequence Dependent Restrictions And Preferences, Nitin Srinath

All Dissertations

In some applications like fabric dying, semiconductor wafer processing, and flexible manufacturing, the machines being used to process jobs must be set up and serviced frequently. These setup processes and associated setup times between jobs often depend on the jobs and the sequence in which jobs are placed onto machines. That is, the scheduling of jobs on machines must account for the sequence-dependent setup times as well. These setup times can be a major factor in operational costs. In fabric dyeing processes, the sequence in which jobs are processed is also important for quality, i.e., there is a strong preference …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …

Pharmaceutical Scheduling Using Simulated Annealing And Steepest Descent Method, Bryant Jamison Spencer

Graduate Theses, Dissertations, and Problem Reports

In the pharmaceutical manufacturing world, a deadline could be the difference between losing a multimillion-dollar contract or extending it. This, among many other reasons, is why good scheduling methods are vital. This problem report addresses Flexible Flowshop (FF) scheduling using Simulated Annealing (SA) in conjunction with the Steepest Descent heuristic (SD).

FF is a generalized version of the flowshop problem, where each product goes through S number of stages, where each stage has M number of machines. As opposed to a normal flowshop problem, all ‘jobs’ do not have to flow in the same sequence from stage to stage. The …

Trade-Off Balancing For Stable And Sustainable Operating Room Scheduling, Amin Abedini

Theses and Dissertations--Mechanical Engineering

The implementation of the mandatory alternative payment model (APM) guarantees savings for Medicare regardless of participant hospitals ability for reducing spending that shifts the cost minimization burden from insurers onto the hospital administrators. Surgical interventions account for more than 30% and 40% of hospitals total cost and total revenue, respectively, with a cost structure consisting of nearly 56% direct cost, thus, large cost reduction is possible through efficient operation management. However, optimizing operating rooms (ORs) schedules is extraordinarily challenging due to the complexities involved in the process. We present new algorithms and managerial guidelines to address the problem of OR …

Methods To Support The Project Selection Problem With Non-Linear Portfolio Objectives, Time Sensitive Objectives, Time Sensitive Resource Constraints, And Modeling Inadequacies, Neil C. Ranly

Theses and Dissertations

The United States Air Force relies upon information production activities to gain insight regarding uncertainties affecting important system configuration and in-mission task execution decisions. Constrained resources that prevent the fulfillment of every information production request, multiple information requestors holding different temporal-sensitive objectives, non-constant marginal value preferences, and information-product aging factors that affect the value-of-information complicate the management of these activities. This dissertation reviews project selection research related to these issues and presents novel methods to address these complications. Quantitative experimentation results demonstrate these methods’ significance.

The Developmental Test Scheduling Problem, Joseph E. Schoenbeck

Theses and Dissertations

Developmental testing of aircraft systems in the United States Air Force requires a complex set of resources for each test. The optimal scheduling of those resources is the job of the 412th Test Wing at Edwards Air Force Base. With more than 20 different Combined Task Forces requesting resources for roughly 300 flying missions each week, manual scheduling is a difficult task. The current process takes a team of schedulers several days to get a workable result from which they can start tailoring the final schedule. While concepts and techniques can be taken from industry scheduling problems, the body of …

An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …

Scheduling Strategies For Construction Project Managers Toward On Time Delivery, Paul Shamp

Walden Dissertations and Doctoral Studies

Construction management projects involve complex, dynamic environments resulting in uncertainty and risk, compounded by demanding time constraints. Research indicated project managers have struggled to identify best practices for scheduling construction projects via critical path methodologies while searching for tools to increase timely job completions and budget profits. The purpose of this single case study was to explore the strategies that construction project managers used to manage scheduled construction project delivery on time. The constructivist philosophical worldview was used as the framework for this study. Data were collected from semistructured interviews from 7 project managers from 5 different construction companies selected …

Sortie Generation Simulation Of A Fighter Squadron, Abdurrahman Sevimli

Theses and Dissertations

The Turkish Air Force utilizes several fighter squadrons to enhance its military capabilities. One of the most critical challenges for these squadrons is generating sorties to meet the currency and demand during both peacetime and wartime. This sortie generation process directly affects the success of both training and operations. In this study, this process is assessed using a discrete event simulation. Air Force decision makers require a simulation tool to conduct “what-if” analysis on how potential changes in the environment affect an F-16 fighter squadron’s sortie generation process. Creating a usable simulation provides decision makers with a flexible tool to …

Operational Planning In Combined Heat And Power Systems, Hariharan Gopalakrishnan

Doctoral Dissertations

This dissertation presents methodologies for operational planning in Combined Heat and Power (CHP) systems. The subject of experimentation is the University of Massachusetts CHP system, which is a 22 MWe/640 MBh system for a district energy application. Systems like this have complex energy flow networks due to multiple interconnected thermodynamic components like gas and steam turbines, boilers and heat recovery steam generators and also interconnection with centralized electric grids. In district energy applications, heat and power requirements vary over 24 hour periods (planning horizon) due to changing weather conditions, time-of-day factors and consumer requirements. System thermal performance is highly dependent …

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 …

A Set Union Based Formulation For Course Scheduling And Timetabling, Jesse Paul Bukenberger

Master's Theses

The Course Timetabling Problem is a widely studied optimization problem where a number of sections are scheduled in concert with the assignment of students to sections in order to maximize the desirability of the resulting schedule for all stakeholders. This problem is commonly solved as a linear program with variables for each student or group of students with identical schedules. In this paper we explore an alternative formulation that aggregates binary student variables into integer variables denoting the number of students enrolled in a course. Our solution method assumes decomposition of the general schedule into time blocks, and applies a …

Scheduling And Resource Allocation In Wireless Sensor Networks, Yosef Alayev

Dissertations, Theses, and Capstone Projects

In computer science and telecommunications, wireless sensor networks are an active research area. Each sensor in a wireless sensor network has some pre-defined or on demand tasks such as collecting or disseminating data. Network resources, such as broadcast channels, number of sensors, power, battery life, etc., are limited. Hence, a schedule is required to optimally allocate network resources so as to maximize some profit or minimize some cost. This thesis focuses on scheduling problems in the wireless sensor networks environment. In particular, we study three scheduling problems in the wireless sensor networks: broadcast scheduling, sensor scheduling for area monitoring, and …

Algorithmic And Mathematical Programming Approaches To Scheduling Problems With Energy-Based Objectives, Kan Fang

Open Access Dissertations

This dissertation studies scheduling as a means to address the increasing concerns related to energy consumption and electricity cost in manufacturing enterprises. Two classes of problems are considered in this dissertation: (i) minimizing the makespan in a permutation flow shop with peak power consumption constraints (the PFSPP problem for short) and (ii) minimizing the total electricity cost on a single machine under time-of-use tariffs (the SMSEC problem for short). We incorporate the technology of dynamic speed scaling and the variable pricing of electricity into these scheduling problems to improve energy efficiency in manufacturing.The challenge in the PFSPP problem is to …

Vehicle Minimization For The Multimodal Pickup And Delivery Problem With Time Windows, Benjamin A . Clapp

Theses and Dissertations

The algorithm proposed here is used for heuristic solutions for the Multimodal Multiple Vehicle Routing Problem with Unloading Capacity, Pickup and Dropoff, and Time Windows, solved so as to minimize the number of vehicles used, subject to varying objective function values for each vehicle. The MVRP is simplified and split into a routing problem and a scheduling problem. The routing problem is addressed by Dijkstra's Algorithm. This generates a new network for the second stage of the algorithm. It is assumed that the shortest path is the correct path to use, and shipments each travel unimodally. The scheduling problem is …

Meta-Heuristics Analysis For Technologically Complex Programs: Understanding The Impact Of Total Constraints For Schedule, Quality And Cost, Henry Darrel Webb

Engineering Management & Systems Engineering Projects for D. Eng. Degree

Program management data associated with a technically complex radio frequency electronics base communication system has been collected and analyzed to identify heuristics which may be utilized in addition to existing processes and procedures to provide indicators that a program is trending to failure. Analysis of the collected data includes detailed schedule analysis, detailed earned value management analysis and defect analysis within the framework of a Firm Fixed Price (FFP) incentive fee contract.

This project develops heuristics and provides recommendations for analysis of complex project management efforts such as those discussed herein. The analysis of the effects of the constraints on …

Optimization Models And Approximate Algorithms For The Aerial Refueling Scheduling And Rescheduling Problems, Sezgin Kaplan

Engineering Management & Systems Engineering Theses & Dissertations

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for fighter aircrafts (jobs) on multiple tankers (machines) to minimize the total weighted tardiness. ARSP can be modeled as a parallel machine scheduling with release times and due date-to-deadline window. ARSP assumes that the jobs have different release times, due dates, and due date-to-deadline windows between the refueling due date and a deadline to return without refueling. The Aerial Refueling Rescheduling Problem (ARRP), on the other hand, can be defined as updating the existing AR schedule after being disrupted by job related events including the …

Exact And Heuristic Algorithms For The Job Shop Scheduling Problem With Earliness And Tardiness Over A Common Due Date, Leonardo Bedoya-Valencia

Engineering Management & Systems Engineering Theses & Dissertations

Scheduling has turned out to be a fundamental activity for both production and service organizations. As competitive markets emerge, Just-In-Time (JIT) production has obtained more importance as a way of rapidly responding to continuously changing market forces. Due to their realistic assumptions, job shop production environments have gained much research effort among scheduling researchers. This research develops exact and heuristic methods and algorithms to solve the job shop scheduling problem when the objective is to minimize both earliness and tardiness costs over a common due date. The objective function of minimizing earliness and tardiness costs captures the essence of the …

Optimization Model For Base-Level Delivery Routes And Crew Scheduling, Young-Ho Cha

Theses and Dissertations

In the U.S. Air Force, a Logistic Readiness Squadron (LRS) provides material management, distribution, and oversight of contingency operations. Dispatchers in the LRS must quickly prepare schedules that meet the needs of their customers while dealing with real-world constraints, such as time windows, delivery priorities, and intermittent recurring missions. Currently, LRS vehicle operation elements are faced with a shortage of manpower and lack an efficient scheduling algorithm and tool. The purpose of this research is to enhance the dispatchers' capability to handle flexible situations and produce "good" schedules within current manpower restrictions. In this research, a new scheduling model and …

A Combined Adaptive Tabu Search And Set Partitioning Approach For The Crew Scheduling Problem With An Air Tanker Crew Application, Todd E. Combs

Theses and Dissertations

This research develops the first metaheuristic approach to the complete air crew scheduling problem. It develops the first dynamic, integrated, set-partitioning based vocabulary scheme for metaheuristic search. Since no benchmark flight schedules exist for the tanker crew scheduling problem, this research defines and develops a Java™ based flight schedule generator. The robustness of the tabu search algorithms is judged by testing them using designed experiments. An integer program is developed to calculate lower bounds for the tanker crew scheduling problem objectives and to measure the overall quality of solutions produced by the developed algorithms.

A Value Focused Thinking Approach To Academic Course Scheduling, Shane A. Knighton

Theses and Dissertations

In 1997, the School of Engineering of the United States Air Force Institute of Technology began exploring ways of automating the academic course scheduling process. The administration desired an expedient approach for course scheduling which supports the institute's mission of "providing scientific and technological education" to officers from all branches of military service, as well as international military forces. The scheduling approach needed to be flexible, efficient, and represent the institute's values and principles. Decision Analysis (DA) and specifically, Value Focused Thinking (VFT), is used to decompose the complex problem of academic course scheduling and determine the factors that are …

Scheduling And Sequencing Arrivals To A Stochastic Service System, Peter M. Vanden Bosch

Theses and Dissertations

Optimization of scheduled arrival times to an appointment system is approached from the perspectives of both queueing and scheduling theory. The appointment system is modeled as a one-server, first-come-first-served, transient queue with independent, distinctly distributed service times and no-show rates. If a customer does show, it is assumed to be punctual. The cost of operating the appointment system is a convex combination of customers' waiting times and the server's overtime. While techniques for finding the optimal static and dynamic schedules of arrivals have been proposed by other researchers, they mainly have focused on identical customers and strictly punctual arrivals. This …

Procedures For Testing Deterministic Scheduling Models: A Dakota Case Study, Keith H. Mccready

Theses and Dissertations

The DAKOTA scheduling system has been proposed for use in the United States Air Forces Europe's (USAFE's) Operational Support Airlift (OSA) scheduling. This thesis examines the OSA scheduling topic and reviews the relevant literature on vehicle routing, concluding that exact methods are intractable for large problem sizes. Consequently, heuristic methods must be considered. This thesis takes a detailed look at the DAKOTA heuristic. It examines the concepts of Validation, Verification and Accreditation (VV&A), particularly as they apply to heuristics and algorithms. It then defines what measures of performance may prove useful in judging heuristics and algorithms in general, and details …

An Improved Heuristic For Intercontinental Ballistic Missile Crew Scheduling, Michael D. Shirley Jr.

Theses and Dissertations

Creating monthly schedules for missile crews is a complex and time-consuming problem. Thousands of events must be scheduled for several hundred missile officers. The rules and regulations governing the problem are numerous, and there are currently no established measures for missile crew schedules. The scheduling software currently available only schedules a fraction of the events. The objectives of this research were to create a rule-based heuristic which could quickly produce feasible or near-feasible schedules, to make the scheduling process paperless, and to develop possible measures of effectiveness for missile crew schedules. The research was successful in each of these areas. …