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Full-Text Articles in Engineering

Relating Initial Budget To Program Growth With Rayleigh And Weibull Models, Eric J. Unger Mar 2001

Relating Initial Budget To Program Growth With Rayleigh And Weibull Models, Eric J. Unger

Theses and Dissertations

Previous research on completed defense R&D shows that contract expenditures can be fit well with a Rayleigh model. With fixed outlay rates, as prescribed by the OSD comptroller, the budget profile must have most of the funds in the early years to produce Rayleigh-distributed expenditures. R&D programs with more delayed funding profiles may also produce expenditures that a Rayleigh model fits through schedule slips and cost overruns. This research tests how well the initial funding profile produces Rayleigh-distributed expenditures that can be related to the program's final cost overrun and schedule slips. Based only on the initial budget profile, we …


The Effect Of Improving The Logistics Pipeline On Supply Support Of Aerospace Expeditionary Forces, Steven L. Martinez Mar 2001

The Effect Of Improving The Logistics Pipeline On Supply Support Of Aerospace Expeditionary Forces, Steven L. Martinez

Theses and Dissertations

One of the biggest considerations for an Aerospace Expeditionary Force (AEF), in terms of cost and airlift requirement, is the use of aircraft spares kits to support combat operations. To date, these kits are built on the assumption that there would be no resupply for the first 30 days of a contingency. However, with more efficient transportation and information resources available today, it seems logical that resupply would occur much more quickly. If so, the Air Force should be able to trim its wartime stocks of aircraft spares. This thesis investigated the effect of improving the logistics pipeline on the …


Estimating C-17 Operating And Support Costs: Development Of A System Dynamics Model, Christopher D. Purvis Mar 2001

Estimating C-17 Operating And Support Costs: Development Of A System Dynamics Model, Christopher D. Purvis

Theses and Dissertations

This research provides justification for experimenting with system dynamics (SD) for performing Operation and Support Cost estimates. For the C-17 Globemaster III cargo aircraft, these costs could exceed $64 billion dollars. Also, many of our weapon systems are beginning to reach the end of their effective life span, and discussions about the impact of aging, on aircraft, has become a hot topic in the literature. System Dynamics is a modeling methodology developed in 1958, but never used extensively for cost estimating. SD offers unique capabilities to the cost estimator, including the ability to model causal relationships. This capability offers the …


The Distributer's Three-Dimensional Pallet-Packing Problem: A Human Intelligence-Based Heuristic Approach, Erhan Baltacioglu Mar 2001

The Distributer's Three-Dimensional Pallet-Packing Problem: A Human Intelligence-Based Heuristic Approach, Erhan Baltacioglu

Theses and Dissertations

The Distributor's Pallet Packing Problem is to load a set of distinct boxes with given dimensions on pallets or in containers to maximize volume utilization. This problem is still in its early stages of research, but there is a high level of interest in developing effective models to solve this NP-hard problem to reduce the time, energy and other resources spent in packing pallets. In its search to improve operations, the Air Force is also making an effort to solve this problem. Building an analytical model and developing a genetic algorithm approach have been tried, but the problem needs more …


Requirements-Based Methodology For Determining Age Inventory Levels, James A. Mackenna Mar 2001

Requirements-Based Methodology For Determining Age Inventory Levels, James A. Mackenna

Theses and Dissertations

The purpose of this research was to illuminate crucial areas in analyzing AGE needs on an operational flightllne and assist in determination of AGE inventory levels. Further refinements could result in more objective and accurate assessments of actual flightline AGE needs and associated risks involved with reduction of AGE inventory levels. The research in this thesis consists of a discrete event simulation to determine desired AGE inventory level through an analysis of aircraft launches and wait time for AGE support by varying AGE (mean time between failure) MTBF and AGE inventory. Stochastic inputs for aircraft failures, AGE delivery times, and …


A Force Structuring Model For A Moderately-Sized Nato Country, Hakan Bal Mar 2001

A Force Structuring Model For A Moderately-Sized Nato Country, Hakan Bal

Theses and Dissertations

The purpose of this research is to develop a mathematical model which will aid the decision-makers of a moderately-sized NATO country to develop their future force structure composition. As the number of alternatives grows, and as the consequences become more important and more uncertain, the force structuring decision becomes increasingly difficult. The valuable lessons of past experience cannot be ignored. However, when one considers the high rotation rates of most countries' air forces, the rapid change in technology and the vast array of options available, even the most experienced leaders need some assistance. Hence, decision support tools are needed to …


Aircraft Maintenance Performance: The Effects Of The Functional Decentralization Of On-Equipment Maintenance, Mark A. Commenator Mar 2001

Aircraft Maintenance Performance: The Effects Of The Functional Decentralization Of On-Equipment Maintenance, Mark A. Commenator

Theses and Dissertations

The Air Force has implemented various aircraft maintenance organizational structures. The implementation of the Objective Wing in the early 1990s was the latest occurrence of reorganization. This research looks at the effect of the type of aircraft maintenance organizational structure on aircraft maintenance performance. The type of organizational structure was defined by the functional centralization of the on-equipment maintenance. Aircraft maintenance performance was measured using TNMCM rates, fix rates, repeat/recur rates, man-hours per flying hour, and scheduling effectiveness rates. Three F-15 wings and three F-16 wings were selected to compare the changes in aircraft maintenance performance and to determine if …


Forecasting Readiness: Using Regression To Predict The Mission Capability Of Air Force F-16 Fighter Aircraft, Steven A. Oliver Mar 2001

Forecasting Readiness: Using Regression To Predict The Mission Capability Of Air Force F-16 Fighter Aircraft, Steven A. Oliver

Theses and Dissertations

According to many, the readiness of America's forces deteriorated in the 1990s. In the Air Force, the combat readiness of its fighter aircraft has declined. One of its indicators of combat readiness, the mission capable rate, is used to identify the percentage of aircraft unable to perform their missions. From FY94-FY98, the aggregate total not mission capable rate for maintenance steadily increased from 14% to 18.2% while total not mission capable rate for supply increased from 5.5% to 17.5% between FY86 and FY00. The USAF uses the funding/Availability Multi-Method Allocator for Spares model to forecast these rates for its aircraft. …