Browsing by Author "Ozbek, Mehmet, committee member"

Now showing 1 - 6 of 6

Open Access
An enterprise system engineering analysis of KC-46A maintenance program decision-making
(Colorado State University. Libraries, 2023) Blond, Kyle E., author; Bradley, Thomas, advisor; Ender, Tommer, committee member; Conrad, Steven, committee member; Herber, Daniel, committee member; Ozbek, Mehmet, committee member
The KC-46A Pegasus is a United States Air Force (USAF) tanker, transport, and medical evacuation commercial derivative aircraft based on the Boeing 767. It is a top acquisition priority to modernize the USAF's refueling capabilities and is governed by a lifecycle sustainment strategy directed by USAF commercial variant policies aligned to Federal Aviation Administration (FAA) policy. While this strategy provides robust mechanisms to manage the KC-46A's performance during its operations and support phase, opportunity exists for the KC-46A sustainment enterprise to better achieve reliability, availability, maintainability, and cost (RAM C) objectives through enhancing KC-46A maintenance program decision making in the context of USAF and FAA policies. This research characterizes the KC-46A maintenance program as an industrial enterprise system governing the maintenance, repair, overhaul, and modification of KC-46A aircraft. Upon this basis, enterprise systems engineering (ESE) characterizes the KC-46A maintenance program and identifies decision making improvement opportunities in its management. Canonical ESE viewpoints are tailored to abstract the organizations, processes, and information composing KC-46A maintenance program decision making and model how decision support methods can better achieve KC-46A sustainment enterprise objectives. A decision making framework then evaluates the RAM C performance of KC-46A maintenance tasks as part of the KC-46A Continued Analysis and Surveillance System (CASS) program. The framework's heuristics classify the compliance, effectiveness, and optimality of a maintenance task to prescribe KC-46A CASS responses. A rule based expert system applies this framework and serves as the knowledge engine for the KC-46A CASS decision support system referred to as the "Pegasus Fleet Management Tool." A focus group of KC-46A sustainment experts evaluated the framework and produced consensus that it advances the state of the art in KC-46A maintenance program decision making. A business case analysis roadmaps the programmatic and technical activities required to implement the framework in PFMT and improve KC-46A sustainment.
Embargo
Commercial construction ethical decision making: authentic case studies
(Colorado State University. Libraries, 2023) Weber, John R., author; Makela, Carole, advisor; Anderson, Sharon, committee member; Folkestad, James, committee member; Ozbek, Mehmet, committee member
This study was developed from 30 years of experiences in commercial construction. In addition to 20 case studies on ethical decision making, perspectives of instructors who taught at American Council of Construction Educators (ACCE) accredited Construction Management (CM) programs were included. These perspectives were considered to improve effectiveness. Literature found on the topic was minimal with most from government press releases. A Qualtrics survey was sent to 996 CM instructors with a potential sample size of 961 where 78 responded (8.12%). Case study effectiveness, the role and techniques used, as well as themes in literature were analyzed. Quantitative and qualitative data contributed to the development and refinement of 20 authentic case studies. Over 95% of instructors perceived it their role to teach ethical decision making; strongly agreed (45.59%), agreed (50.00%), neutral (2.94%), disagreed (1.47%), and none strongly disagreed. Instructors perceived construction as having unique pressures varied; Yes (67.65%), No (26.47%), with 5.88% did not know. When asked if ethical transgressions were systemic; Yes (38.24%), No (45.59%), and 14.71% did not know. Did instructors perceive an "everybody does it" attitude; Yes (42.65%), No (47.06%), and 10.29% did not know. When asked if authentic case studies were readily available; strongly agreed (4.48%), agreed (23.88%), neutral (28.36%), disagreed (35.82%), and strongly disagreed (7.45%).
Open Access
Development of a human factors hazard model for use in system safety analysis
(Colorado State University. Libraries, 2021) Birch, Dustin Scott, author; Bradley, Thomas, advisor; Miller, Erika, committee member; Cale, James, committee member; Ozbek, Mehmet, committee member
Traditional methods for Human Reliability Analysis (HRA) have been developed with specific applications or industries in mind. Additionally, these methods are often complicated, time consuming, costly to apply, and are not suitable for direct comparison amongst themselves. The proposed Human Factors Hazard Model (HFHM) utilizes the established and time-tested probabilistic analysis tools of Fault Tree Analysis (FTA) and Event Tree Analysis (ETA), and integrates them with a newly developed Human Error Probability (HEP) predictive tool. This new approach is developed around Performance Shaping Factors (PSFs) relevant to human behavior, as well as specific characteristics unique to a system architecture and its corresponding operational behavior. This updated approach is intended to standardize, simplify, and automate the approach to modeling the likelihood of a mishap due to a human-system interaction during a hazard event. The HFHM is exemplified and automated within a commercial software tool such that trade and sensitivity studies can be conducted and validated easily. The analysis results generated by the HFHM can be used as a standardized guide to SE analysts as a well as design engineers with regards to risk assessment, safety requirements, design options, and needed safety controls within the system architecture. Verification and evaluation of the HFHM indicate that it is an effective tool for HRA and system safety with results that accurately predict HEP values that can guide design efforts with respect to human factors. In addition to the development and automation of the HFHM, application within commonly used system safety Hazard Analysis Techniques (HATs) is established. Specific utilization of the HFHM within system or subsystem level FTA and Failure Mode and Effects Analysis (FMEA) is established such that human related hazards can more accurately be accounted for in system design safety analysis and lifecycle management. Lastly, integration of the HFHM within Model-Based System Engineering (MBSE) emphasizing an implementation into the System Modeling Language (SysML) is established using a combination of existing hazard analysis libraries and custom designed libraries within the Unified Modeling Language (UML). The FTA / ETA components of the hazard model are developed within SysML partially utilizing the RAAML (Risk Analysis and Assessment Modeling Language) currently under development by the Object Management Group (OMG), as well as a unique recursive analysis library. The SysML model successfully replicates the probabilistic calculation results of the HFHM as generated by the native analytical model. The SysML profiles developed to implement HFHM have application in integration of conventional system safety analysis as well as requirements engineering within lifecycle management.
Open Access
Differences for employees who use BIM/VDC in the construction workplace
(Colorado State University. Libraries, 2014) Inguva, Girija, author; Clevenger, Caroline, advisor; Ozbek, Mehmet, committee member; Atadero, Rebecca, committee member
There is growing recognition across the US construction industry for the benefits of organizational adoption of Building Information Modeling, also referred to as Virtual Design and Construction (BIM/VDC). One of the key factors that enables successful organizational adoption of new technologies is the adoption of these technologies by key participants, in this case by BIM employees. Their positive experiences at their current organization determine their continuation on a BIM/VDC path, thus leading to consistent organizational adoption and negative experiences could mean that they migrate from a BIM career to a Non-BIM career or to another organization to seek better experiences. This research aims to study the perceptions of BIM employees as compared to the perceptions of Non-BIM employees in the construction industry in four key categories: work life balance, career advancement, workplace experience and skill levels. An online survey is used and responses are compared first using averages and then using Pearson's X2 or Fisher's probability test to test for statistical significance where applicable. Differences inform us of the advantages or challenges of a BIM/VDC career at an individual level. Additionally, differences between men and women are also studied, along with differences between BIM employees from organizations with a separate BIM/VDC department and BIM employees from organizations without a separate BIM/VDC department. The general trends observed in terms of averages indicate that BIM/VDC personnel are generally more satisfied with their jobs and consider common barriers to career advancement to be of lesser relevance than their Non-BIM counterparts. The fact that most differences are not statistically different also suggests that BIM employees may not be treated that differently from Non-BIM employees. Of all groups, the most positive perceptions are reported by male BIM respondents from organizations without separate BIM/VDC departments.
Open Access
Innovative hydrogen station operation strategies to increase availability and decrease cost
(Colorado State University. Libraries, 2019) Kurtz, Jennifer, author; Bradley, Thomas, advisor; Willson, Bryan, committee member; Suryanarayanan, Siddharth, committee member; Ozbek, Mehmet, committee member
Major industry, government, and academic teams have recently published visions and objectives for widespread use of hydrogen in order to enable international energy sector goals such as sustainability, affordability, reliability, and security. Many of these visions emphasize the important and highly-scalable use of hydrogen in fuel cell electric cars, trucks, and buses, supported by public hydrogen stations. The hydrogen station is a complicated system composed of various storage, compression, and dispensing sub-systems, with the hydrogen either being delivered via truck or produced on-site. As the number of fuel cell electric vehicles (FCEVs) on roads in the U.S. have increased quickly, the number of hydrogen stations, the amount of hydrogen dispensed, and the importance of their reliability and availability to FCEV drivers has also increased. For example, in California, U.S., the number of public, retail hydrogen stations increased from zero to more than 30 in less than 2 years, and the annual hydrogen dispensed increased from 27,400 kg in 2015 to nearly 105,000 kg in 2016, and more than 913,000 kg in 2018, an increase of nearly 9 times in 2 years for retail stations. So, although government, industry, and academia have studied many aspects of hydrogen infrastructure, much of the published literature does not address hydrogen station operational and system innovations even though FCEV and hydrogen stations have some documented problems with reliability, costs, and maintenance in this early commercialization phase. In general, hydrogen station research and development has lagged behind the intensive development effort that has been allocated to hydrogen FCEVs. Based on this understanding of the field, this research aims to identify whether integrating reliability engineering analysis methods with extensive hydrogen station operation and maintenance datasets can address the key challenge of station reliability and availability. The research includes the investigation and modeling of real-world hydrogen station operation and maintenance. This research first documents and analyzes an extensive dataset of hydrogen station operations to discover the state-of-the-art of current hydrogen station capabilities, and to identify performance gaps with key criteria like cost, reliability, and safety. Secondly, this research presents a method for predicting future hydrogen demand in order to understand the impact of the proposed station operation strategies on data-driven decision-making for low-impact maintenance scheduling, and optimized control strategies. Finally, based on an analysis indicating the need for improved hydrogen station reliability, the research applies reliability engineering principles to the hydrogen station application through development and evaluation of a prognostic health management system.
Open Access
Using building information modeling to track and assess the structural condition of bridges
(Colorado State University. Libraries, 2014) McGuire, Brendan Michael, author; Atadero, Rebecca, advisor; Clevenger, Caroline, advisor; Ozbek, Mehmet, committee member; Elliott, Jonathan, committee member
National Bridge Inspection Standards do not require documenting damage location during an inspection but bridge evaluation provisions highlight the importance of it. When determining a safe load carrying capacity of a bridge, damage location information is significant because shear and moment limit states are more critical at different locations and member capacities can vary along the length of a span. Capturing damage location information using current methods can be impractical; however, building information modeling (BIM) provides new opportunities in tracking and utilizing this information. A method and prototype implementation to apply BIM software to the operation and maintenance stages of bridges' service lives is presented. The proposed Bridge information modeling for Inspection and Evaluation Method (BIEM) could allow transportation agencies to more efficiently manage bridge inventories using BIM capabilities while incorporating damage location information. The method, created by the author, uses BIM to document damage type, amount, severity, and location information during a bridge inspection. To leverage this information, inspection results are exported from the BIM model into a spreadsheet where a custom subroutine evaluates the structural performance and performs load ratings on selected bridge superstructure elements. In addition, based on the type, amount, and severity of damage, estimated repair quantities are given and maintenance recommendations are provided. The proposed method was field tested on a case study bridge in Larimer County, Colorado. Official inspection reports and load ratings were obtained and a visual inspection of the bridge utilizing supplemental location-based measurements was performed. The BIEM was implemented and numerical results were compared to the official load ratings. Results suggest that documenting the location of deterioration within a bridge element can affect the guidelines for determining a safe load carrying capacity for a bridge. In addition, the opportunity exists for BIM to play a significant role in bridge management in the future as demonstrated by its proven ability to facilitate the inspection and evaluation processes which could ultimately result in more automated practices. Overall, results from this research motivate future work in the study of deterioration modes and their effect on bridge element capacity and tailoring the principles BIM to the later stages of bridges' service lives.