Engineering Commons^™

Investigating The Relationship Of Preventive And Corrective Maintenance In Chiller Assets Using Linear Regression Analysis, Jacob A. Franke

Theses and Dissertations

Asset managers must balance maintenance plans between preventive (PM) and corrective maintenance (CM). While PM plans have been a staple for decades, the benefits achieved have not been thoroughly examined at the asset specific level. This study focuses on the U.S. Air Force chiller portfolio to better understand the relationship between PM and CM, utilizing multiple stages of linear regression modeling and data from 14 US Air Force installations. PM and CM were found to be positively correlated, with PM accounting for relatively small portions of the variance experienced in CM. This study reveals the value of standardized data collection …

Data- Driven Asset Degradation Modeling: An Enterprise-Wide Roof System Case Study, Kurt R. Lamm

Theses and Dissertations

Organizations with large facility and infrastructure portfolios have used asset management databases for over ten years to collect and standardize asset condition data. Decision makers use this data to predict asset degradation and expected service life, enabling prioritized maintenance, repair, and renovation actions that reduce asset life-cycle costs and achieve organizational objectives. However, these asset condition forecasts are calculated using standardized, self-correcting distribution models that rely on continuous functions. This research presents four step wise asset condition forecast models that utilize historical asset inspection data to improve prediction accuracy: (1) Slope, (2) Weighted Slope, (3) Condition-intelligent Weighted Slope, and (4) …

Optimization Of Airfield Parking And Fuel Asset Dispersal To Maximize Survivability And Mission Capability Level, Ryley R. H. Paquette

Theses and Dissertations

While the US focus for the majority of the past two decades has been on combatting insurgency and promoting stability in Southwest Asia, strategic focus is beginning to shift toward concerns of conflict with a near-peer state. Such conflict brings with it the risk of ballistic missile attack on air bases. With 26 conflicts worldwide in the past 100 years including attacks on air bases, new doctrine and modeling capacity are needed to enable the Department of Defense to continue use of vulnerable bases during conflict involving ballistic missiles. Several models have been developed to date for Air Force strategic …

Validation And Improvement Of Reliability Methods For Air Force Building Systems, Patrick A. Deering

Theses and Dissertations

The United States Air Force manages its civil infrastructure resource allocation via a two-dimensional risk model consisting of the consequence of failure and reliability. Air Force civil engineers currently use the BUILDER® Sustainment Management System to estimate and predict reliability at multiple levels within its civil infrastructure systems. Alley (2015) developed and validated a probabilistic model to calculate reliability at the system level. The probabilistic model was found to be a significant improvement over the currently employed BUILDER® model for four major building systems (electrical, HVAC, fire protection, and electrical). This research assessed the performance and accuracy of both the …

Evaluating Storm Sewer Pipe Condition Using Autonomous Drone Technology, Maria T. Meeks

Theses and Dissertations

The United States Air Force (USAF) owns a total of 30.9 million linear feet (LF) of storm sewer pipes valued at approximately $2.3B in its vast portfolio of built infrastructure. Current inventory records reveal that 78% of the inventory (24.1 million LF) is over 50 years old and will soon exceed its estimated service life. Additionally, the USAF depends on contract support while its business processes undervalue in-service evaluations from long-term funding plans. Ultimately, this disconnect negatively impacts infrastructure performance and overall strategic success, and the USAF risks making uninformed decisions in a fiscally constrained environment.

This research presents a …

Mission Dependency Index Of Air Force Built Infrastructure: Knowledge Discovery With Machine Learning, Clark W. Smith

Theses and Dissertations

Mission Dependency Index (MDI) is a metric developed to capture the relative criticality of infrastructure assets with respect to organizational missions. The USAF adapted the MDI metric from the United States Navy’s MDI methodology. Unlike the Navy’s MDI data collection process, the USAF adaptation of the MDI metric employs generic facility category codes (CATCODEs) to assign MDI values. This practice introduces uncertainty into the MDI assignment process with respect to specific missions and specific infrastructure assets. The uncertainty associated with USAF MDI values necessitated the MDI adjudication process. The MDI adjudication process provides a mechanism for installation civil engineer personnel …

A Change Management Approach To Enhance Facility Maintenance Programs, Stanton P. Brown

Theses and Dissertations

A recent study assigned a grade of D+ on the nation's public infrastructure. Because of this poor asset condition, many organizations tend to respond to maintenance in a reactive mode; however, relying on corrective maintenance leads to increased maintenance costs due to unplanned downtime, increased labor costs, and inefficient use of personnel. To address this situation, asset management (AM) principles should be employed to transition organizations towards a proactive maintenance program. Unfortunately, it has been shown that two-thirds of the organizations failed to implement general change efforts. Therefore, an organizational change management framework should be followed to implement a change …