Operational Research Commons^™

A Web-Based Interface For Storing And Executing Simulation Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development of information and communication technology has made Web-based distributed solutions increasingly attractive. Apart from providing other services, the World Wide Web is being looked upon as an environment for hosting modeling and simulation applications. SIMAN is a simulation language that allows users to simulate discrete and continuous systems. In this research, a web-based interface or toolkit has been developed for storing and executing SIMAN simulation models over the Internet. This toolkit consists of a World Wide Web interface to SIMAN and a web-accessible database for storing user models. It provides users an …

Product-Mix Optimiser For An Integrated Steel Plant, Goutam Dutta, Gopal P Singh, P N Roy

IIMB Management Review

Optimal utilisation of constrained resources is one of the most important problems in the area of operations management. The determination of optimal productmix is an extremely difficult task for an organisation producing multiple products in multiple stages, sharing a set of common plant resources and experiencing a fluctuating market over time. In the absence of a quick method to determine optimality under changing conditions, plant managers have to make decisions based on their experience and intuition. 

Application Of Or To Management Practice: An Introduction, H K Lakshman Rao

IIMB Management Review

Customer dissatisfaction with products and services, long queues at hospitals and railway stations, stock out/excess stock situations, overflowing solid waste bins at street corners, delayed deliveries and time lag in new product development, steeply increasing project costs, high rates of wastage in the manufacturing process these are among the numerous instances indicating the lack of systems approach and inadequate appreciation of Operations Research (OR) methods in the Indian management and administrative network scenario.

A Web-Based Interface For Storing And Executing Simulation Model, Ashu Guru, Paul Savory, Robert Williams

Department of Industrial and Management Systems Engineering: Faculty Publications

The dominance of the Internet in the development ofinformation and communication technology has madeWeb-based distributed solutions increasingly attractive.Apart from providing other services, the World Wide Webis being looked upon as an environment for hostingmodeling and simulation applications. SIMAN is asimulation language that allows users to simulate discreteand continuous systems. In this research, a web-basedinterface or toolkit has been developed for storing andexecuting SIMAN simulation models over the Internet.This toolkit consists of a World Wide Web interface toSIMAN and a web-accessible database for storing usermodels. It provides users an easy-to-use environment fordeveloping text-based simulation models using the SIMANsimulation language. It also …

The Pilgrim's Progress: Operations Research In Queuing, G Raghuram

IIMB Management Review

Good management practice is synonymous with applying operations research (OR). Both imply a systematic approach beginning with clarity in problem definition, understanding the objectives and constraints, characterising the alternatives (these three steps constitute  model building), evaluating (analysing) them and finally selecting an alternative for implementation. In addition to this basic methodology, there is also an implication of a quantitative basis to the extent possible. It is this quantitative basis which lends to the common perception that good management practice is much larger than OR

Applications Of Or In The Indian Context, R Sankar, Muthulingam Suresh

IIMB Management Review

Operations Research (OR) originated in England during World War II. The first applications aimed at improving the operational efficiency of the radar defence systems deployed by the Royal Air Force. Very soon thereafter, OR methods and techniques were applied successfully to the resolution of complex industrial and commercial problems in areas such as scheduling, inventory management, strategic planning, resource allocation and transportation.

Application Of Operations Research Techniques To Finance, Kamlesh Kosare

IIMB Management Review

There is a pressing need to find solutions to vari ous problems in finance with the help of operations research techniques, which can be conveniently used, for decision making.

Computer-Based Methods For Constructing Two-Level Fractional-Factorial Experimental Designs With A Requirement Set, Steven L. Forsythe

Theses and Dissertations

This dissertation developed four methodologies for computer-aided experimental design of two-level fractional factorial designs with requirement sets (DOE/RS). The requirement sets identify all the experimental factors and the appropriate interaction terms to be evaluated in the experiment. Taguchi graphs and similar manual methods provide techniques for solving the DOE/RS problem. Unfortunately, these methods are limited because they become difficult to use as the number of factors or interaction terms exceeds ten. This research showed that the DOE/RS problem belongs to a class of difficult-to-solve problems known as NP-Complete. It is the combinatorial nature of NP-Complete problems that causes them to …

Estimating Budget Relationships With A Leontief Input-Output Model, Guenever L. R. Shariff

Theses and Dissertations

Forty years ago, the Office of the Secretary of Defense proposed using the Leontief input-output model to assess tradeoffs in the Department of Defense's (DoD) budget. We demonstrate that the Leontief input-output model can assess tradeoffs in the Air Force's budget. To increase one part of the Air Force's budget, we need to know the interrelationships between that budget area and the other areas. In this research, we look at different methods of how the functional areas might interact. We demonstrate our methodology on two data sets - DoD and the Air Force aggregate budget data. By looking at how …

Routing Optimization Through Computer-Aided Simulation, Madhusudhan Akundi

Electrical & Computer Engineering Theses & Dissertations

Routing has always been a challenging field, and the various techniques of mathematics and operations research have been developed. For commercial organizations, routing has begun to receive extensive attention because of the savings gained in terms of time, money, personnel, and the transportation fleet by developing optimized routing networks. Until recently, it was difficult to develop optimized networks due to the computational difficulties of the problem. However, with the advancement in computer technology and processing speeds, it has become possible to simulate a large number of routing scenarios and determine optimal solutions for a given set of constraints. Not only …

Process Flow Optimization Studies Through Discrete Event Simulation, Milind Chokshi

Electrical & Computer Engineering Theses & Dissertations

Computer-aided simulation has begun to emerge as a powerful tool for numerical analysis of the behavior and anticipated performance of industrial systems and their optimization. Applications include materials handling, storage and controls systems, prediction of manufacturing efficiencies, and production optimization. Simulations are used to test baseline models and subsequently analyze new production concepts, operating strategies, and planned procedures prior to costly implementation.

The study of process flows in a manufacturing environment is difficult due to its inherent stochastic nature. Breakdown of the sub-systems and failures of machines is a random process and needs to be solved based on concepts of …

A Systems-Based Methodology For The Construction And Representation Of Organizational Knowledge Systems, Willie James Mcfadden

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop and apply a systems-based, analysis methodology which constructs and represents an organization's knowledge system. The research inquiry was guided by four questions: (1) “what is an organizational knowledge system?” (2) “how can it be made explicit?” (3) “does the representation accurately depict the organization's perspective of their unique knowledge system?” and (4) “what results from the deployment of the organizational knowledge system methodology?” The resultant answers to these research questions advanced and established the theoretical conception of an organization's knowledge system through the development of a methodology that fosters the construction and …

An Integrated Engineering-Computation Framework For Collaborative Engineering: An Application In Project Management, Hisham Mohamed El-Sayed Abdelsalam

Mechanical & Aerospace Engineering Theses & Dissertations

Today's engineering applications suffer from a severe integration problem. Engineering, the entire process, consists of a myriad of individual, often complex, tasks. Most computer tools support particular tasks in engineering, but the output of one tool is different from the others'. Thus, the users must re-enter the relevant information in the format required by another tool. Moreover, usually in the development process of a new product/process, several teams of engineers with different backgrounds/responsibilities are involved, for example mechanical engineers, cost estimators, manufacturing engineers, quality engineers, and project manager. Engineers need a tool(s) to share technical and managerial information and to …

A Tabu Search Metaheuristic For The Air Refueling Tanker Assignment Problem, Shay R. Capehart

Theses and Dissertations

In a joint effort between Air Mobility Command (AMC) and the Air Force Institute of Technology, we present a Tanker Assignment Problem (TAP) Tool capable of providing tanker mission plans for deployment scenarios. Due to the complex nature of extracting a mission plan from the Combined Mating and Ranging Planning System (CMARPS), AMC requires a tool to provide similar results in a simpler and less time consuming manner. The tool developed allows AMC to input several receiver groups consisting of various aircraft types and numbers. Each receiver group contains a point of origin and destination, with the option of providing …

An Incentive Model For International Telecommunications, Jeffrey R. Del Vecchio

Theses and Dissertations

This study developed a new defensive model for global voice communications. It uses a n-person, zero-sum, cooperative and non-cooperative game to optimize the coalitions revenue after the possibility of a network service provider being tampered by an adversary. This research optimized two measures of effectiveness (coalition revenue and network provider revenue) of international telecommunications coalitions by hardening network service providers and improving their respective revenue with incentives. A multi-criteria optimization problem was developed to establish the strategic competition between the coalition defender and attacker. Irrespective of the amount of incentives, a applicable hardening and tampering strategy can be obtained. All …

A Java Universal Vehicle Router In Support Of Routing Unmanned Aerial Vehicles, Robert W. Harder

Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) help the military gather information in times of peace and war. During a mission, typically 100 sites or more, a UAV will frequently be re-tasked to visit a pop-up threat, leaving the operator to determine the best way to finish the day's list of sites after the re-tasking. I develop a prototype application to serve the needs of a specific customer, the 11th Reconnaissance Squadron, by helping them preplan missions and dynamically re-task UAVs. This prototype application is built on a reusable airframe router called the core AFIT Router, which can later be added to more …

Using Simulation To Model An Army Recruiting Station With Seasonality Effects, David C. Longhorn

Theses and Dissertations

One of the toughest jobs in the Army is that of the recruiter. Recruiters are tasked with the awesome job of convincing young men and women to lay down their lives and freedoms for their country, and oftentimes for less money than can be earned in the safer environment of America's booming economy. Recruiters face enormous pressure from commanders to meet the mandated Army manning levels set each year by Congress. As the Army begins the 21st century, it is faced with having to support an increasing number of deployments with fewer soldiers. Soldiers face long and difficult days with …

Toward Validating Vertical Aggregation In Object Oriented Simulation, George W. Johnson Jr.

Theses and Dissertations

Recent interest in studying the nonlinear effects of intelligence, surveillance, and reconnaissance in combat models has prompted researchers to employ vertical aggregation in object-oriented simulations. Traditional horizontal aggregation falls short for its inability to provide accurate means for nonlinear functions. Averaging a group of objects that exhibit nonlinear behavior provides a linear approximation to the mean, which is not necessarily the expected value of the underlying nonlinear function. Vertical aggregation explicitly models individual objects, thus preserving their nonlinear behaviors. In this research, a validation procedure is derived to study the aptness of vertical aggregation methods. Validation is carried out by …

A Hybrid Jump Search And Tabu Search Metaheuristic For The Unmanned Aerial Vehicle (Uav) Routing Problem, Gary W. Kinney Jr.

Theses and Dissertations

In this research, we provide a new meta-heuristic, a jump search I tabu search hybrid, for addressing the vehicle routing problem with real-life constraints. A tour construction heuristic creates candidate solutions or jump points for the problem. A tabu search algorithm uses these jump points as starting points for a guided local search. We provide statistical analysis on the performance of our algorithm and compare it to other published algorithms. Our algorithm provides solutions within 10% of the best known solutions to benchmark problems and does so in a fraction of the time required by competing algorithms. The timeliness of …

A Validation Assessment Of The Storm Air-To-Air Prototype Algorithm, David M. Pugh

Theses and Dissertations

A validation assessment of the new STORM air-to-air prototype algorithm is accomplished using structural and output validation techniques. In the structural validation phase, the algorithms, code, and assumptions are evaluated to determine if the implementation of the model will match the intent of the designers. The components of the algorithm are compared to its predecessor, THUNDER, to evaluate if the prototype nnproves upon the weaknesses of THUNDER. In the output validation phase, the results of the model are evaluated to determine the extent to which the implementation of the model matches expected outcomes. Sensitivity analysis is presented to provide insight …

Leontief Metamodeling For Military Strategic Effects, Anthony W. Snodgrass

Theses and Dissertations

In this research, we propose and demonstrate an approach to incorporate currently un-modeled interactions into an existing or a new combat model or simulation. We apply the Leontief Input-Output model, which is a macro-economic model that measures the interactions between major industrial sectors of an economy, as a metamodel that periodically assesses the status of various combat units and support functions. If needed resources are insufficient, appropriate degrades are input into the combat model. As a result, dependencies that are not in the combat model are incorporated. Hence, we can assess the strategic or cascading effects of destroying a set …

Simulation Evaluation Of The Combat Value Of A Standoff Precision Airdrop Capability, Michael W. Varner

Theses and Dissertations

This project is a simulation evaluation of the developmental standoff precision airdrop (SOPAD) capability. SOPAD is a new technology under consideration to deliver supplies to forward-deployed units using either a semi-rigid wing or a guided parafoil. These delivery systems allow airdrop of supplies from altitudes of 25,000 feet and distances 25 miles from the delivery point. Using global positioning system guidance, on board navigational computers, and automatic steering mechanisms, the delivery system flies to the target following a designated flight plan. The concept includes delivering supplies to remote and potentially hostile areas without endangering the supply aircraft. In addition, supplies …

A Greedy Multiple-Knapsack Heuristic For Solving Air Mobility Command’S Intratheater Airlift Problem, Nicholas J. Zeisler

Theses and Dissertations

This research develops a methodology using a greedy heuristic to solve Air Mobility Command's intratheater airlift scenario as a multiple knapsack problem. The objective is to maximize throughput in a theater given a vehicle mixture and assignment scheme. The model allows for a heterogeneous, user defined vehicle mix in a theater consisting of up to five bed down locations and up to seven forward operating locations. First, we preprocess routes, eliminating the large number of unattractive route choices in the problem. Then using a greedy heuristic, we select routes and assign them to aircraft located at any or all of …

Using Rsm, Doe, And Linear Regression To Develop A Metamodel To Predict Cargo Delivery Of A Time Phase Force Deployment Document, Kenneth S. Browne

Theses and Dissertations

Air Mobility Command (AMC) uses the Airlift Flow Model as their primary tool to estimate the amount of cargo delivered in a Time Phase Force Deployment Document (TPFDD). The primary objective of this research was an exploratory investigation in the development of a metamodel to predict the amount of cargo delivered from a TPFDD by AMC into a theater. In creating a valid metamodel the analyst would be able to quickly provide the decision-maker with accurate insights should input parameters change. This would save valuable time and replace the need to physically change the input parameters and re-run the simulation. …

Approximation Model Building For Reliability & Maintainability Characteristics Of Reusable Launch Vehicles, Resit Unal, W. Douglas Morris, Nancy H. White, Roger A. Lepsch, Richard W. Brown

Engineering Management & Systems Engineering Faculty Publications

This paper describes the development of parametric models for estimating operational reliability and maintainability characteristics for reusable launch vehicle concepts, based on vehicle size and technology support level. A reliability and maintainability analysis tool (RMAT) and response surface methods are utilized to build parametric approximation models for rapidly estimating operational reliability and maintainability characteristics such as mission completion reliability. These models that approximate RMAT, can then be utilized for fast analysis of operational requirements, for lifecycle cost estimating and for multidisciplinary design optimization.

Developing A Parametric Cost Model For Operating Costs Of Army Ground Combat Weapon Systems, James O. Winbush Jr.

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop a parametric cost model for predicting operating costs of Army ground combat weapon systems. The model is intended to be used during the first two phases of the Army's acquisition process. The research necessary to develop the model was guided by two questions: what weapon system characteristics (such as weight, horsepower, fuel consumption, primary mission, NBC protection, fire control and night fighting capability) impact directly on operating ground combat systems; and what is the form of the parametric model for operating costs for ground combat systems? The study extends the bounds of …