Quantifying the Impacts of Delayed Maintenance of Airport Assets: A Guide (2024)
Chapter: 8 Summary and Recommendations for Future Research
CHAPTER 8
Summary and Recommendations for Future Research
8.1 Key Points
All types of airports, irrespective of their size, have difficulty procuring enough funds to maintain all their assets due to various constraints. Some airports’ assets need to be regularly maintained due to 14 CFR Part 139 requirements, and maintenance of those assets is funded by the FAA. Airports need to create their own budget to maintain other assets. Therefore, one of the major responsibilities of the operation and maintenance division is to efficiently prepare the maintenance budget required for the following fiscal year. If the budget cannot fund maintenance of all airport assets, they need to calculate the impact of delaying maintenance on those assets. Airport asset managers can show the airport’s higher authority figures the effects of delayed maintenance on the life of assets and the long-term maintenance and replacement budget.
Airport maintenance can be divided into three types: preventive, reactive, and predictive. Preventive maintenance activities include tasks that mitigate the degradation of an infrastructure system or its components. Preventive maintenance, performed regularly or as needed, can extend the service life of facilities and components and can yield the optimum performance outputs of assets. This results in reduced costs and improved user satisfaction. Reactive maintenance means fixing the system or components after they break, without performing preventive maintenance. This type of activity incurs higher system costs compared to conducting regular preventive maintenance. Reactive maintenance can have adverse effects on customer service and can reduce revenue. Predictive maintenance involves testing and monitoring equipment and facilities and predicting potential failures. This method is used for equipment and vehicles. If predictive and preventive maintenance are simultaneously implemented, it will ensure a minimal impact on an airport’s operation and safety.
Airport officials and policymakers need to understand the value of preventive maintenance of their assets. Preventive maintenance of assets is critical in providing efficient service to air passengers and increasing the life of the assets. If airports cannot perform preventive maintenance of their critical assets every year as required, those assets need to be replaced before they reach the end of their economic lives. Replacing failed assets is more costly than performing regular maintenance. Some critical airfield assets include runway pavement, runway and taxiway lighting, airfield signs, airfield markings, and hangars. Landside assets include, but are not limited to, service vehicles, snow removal equipment, terminal buildings, heating and cooling systems, baggage handling systems, passenger boarding bridges, and APM systems.
The research team conducted several interviews with airport assets managers to identify the best practices for preparing maintenance budgets for airport assets and the procedure to quantify the consequence of delaying maintenance on their assets. The following are practices
for airports to consider while preparing their maintenance budget with and without delayed scenarios:
- Prepare the maintenance budget based on the condition of the assets.
- Prioritize maintenance of the assets based on their impact on the safety and operation of the planes and the comfort of air passengers.
- Prepare the maintenance budget 6-9 months before the fiscal year begins.
- Prepare the short-term and long-term maintenance budget so that the impact of delaying the maintenance of assets can be evaluated effectively.
- Understand the value of short-term and long-term maintenance budgeting.
- Involve all appropriate airport departments when preparing the long-term and short-term maintenance budgets.
- Create working relationships with various departments while preparing maintenance budgets.
- Implement the basic framework described in this report, and use spreadsheet tools developed to determine the consequences of delayed maintenance of some airside and landside airport assets.
- Keep a detailed inventory of all airport assets, and update the inventory annually.
- Perform a condition assessment of all the airport assets, and update the record in the database system.
- Use numeric or categorical variables to describe the condition of assets. For example, PCI can be used to show the condition of pavement. Similarly, the condition categories of Excellent, Good, Fair, Poor, and Needs Replacement can be used for other airport assets.
- Identify the preventive maintenance activities performed on assets.
- Keep a record of labor hours spent on maintaining each asset separately.
- Keep and update the materials used in maintaining each airport asset.
- Use a maintenance management system, such as CMMS, however, input and update data in the system regularly.
- Use the collected data while making decisions during maintenance budget preparations.
- Update the labor and materials data at the end of each year.
- Collect and record lessons learned during the preparation of the maintenance budget.
- Train airport maintenance division personnel to follow these practices.
- Obtain resources (funding, staffing software, tools) to maintain the database systems.
Understandably, some airports might have difficulty adopting the practices mentioned above on the first attempt. Due to levels of federal and state funding, aging airport infrastructure and other assets, and increasing air passenger volume and high-level customer satisfaction demands, airports are facing substantial pressure to be more efficient in maintaining and operating their assets. It is necessary for every airport, irrespective of its size, to be more innovative in maintaining its assets. Therefore, the airport industry must begin to apply these practices so that effective and accurate maintenance budgets can be prepared.
8.2 Spreadsheet Tools to Assist Airport Asset Managers
The research team collected data related to certain airport assets’ inventory, condition assessments, maintenance unit costs, and deterioration models to develop spreadsheet tools for determining the preventive maintenance budgets of nine airport assets and quantifying the impact of delayed maintenance on overall airport budgets. The research team developed spreadsheet tools for four airside and five landside assets. The spreadsheet tools were prepared for airside assets including runway pavement, runway lighting, airfield signs, and airfield markings. In addition, the spreadsheet tools were prepared for landside assets such as service vehicles, snow removal equipment, HVAC systems, baggage handling systems, and passenger boarding bridges.
These spreadsheet tools are meant to be a data management resource for airport asset managers to better estimate the regular maintenance budget and to quantify the impact of delayed maintenance on these assets. These spreadsheet tools can be used as guidelines when determining the impact of delayed maintenance. These tools already have the maintenance labor hours, materials cost, cost inflation factors, theoretical deterioration models with and without delayed maintenance, and present value cost conversion process. The tools were developed to be flexible and customizable for a variety of purposes and system sizes. These spreadsheet tools have many prepopulated input cells, but the user may also easily customize those options. Airport users can use their own asset inventory, labor hours, cost, inflation factors, and deterioration models to determine the delayed maintenance costs of these nine airport assets.
The intended use of the spreadsheet tools is to show the airports that the consequence of delaying asset maintenance can be quantified monetarily. However, the spreadsheet tools generate estimates based on the input values. There are certain assumptions used to generate these delayed maintenance budgets. Therefore, if the assumptions are not valid for their airports, the number generated will not make sense. It is suggested to use these spreadsheet tools carefully when quantifying the impact of delayed maintenance on airport assets. Also, the team provided the option of delaying maintenance up to 10 years, but this may not be feasible for several airport assets due to their importance in the safety and operation of planes. These spreadsheet tools have also not considered delayed maintenance impacts on the safety of the planes and the comfort of the passengers. The estimates generated by these spreadsheet tools are merely calculated based on the impact on maintenance and replacement costs of the assets. The research team prepared an easy-to-use guide for airports so that they can effectively use these spreadsheet tools for their budgeting purposes. The guide is supplemental to this report.
8.3 Areas of Future Research
The research team collected extensive data to develop the spreadsheet tools for nine airport assets. However, due to the scope of the research, the spreadsheet tools could not be developed for other critical assets. The research team described the process of collecting and using data to develop spreadsheet tools for terminal buildings, hangars, and APMs. Therefore, future research could involve preparing spreadsheet tools for the following critical assets by collecting comprehensive data from airport case study projects:
- Terminal building envelope,
- Hangars,
- Airfield visual and navigational aids (NAVAIDS),
- Maintenance and storage buildings,
- Fueling facilities,
- Deicing facilities,
- Parking garage,
- Drainage,
- Access roads,
- APM,
- Elevators,
- Moving walkways, and
- Overhead bridges.
The research team found that most airports are using traditional ways of preparing maintenance and replacement budgets for airport assets without considering the performance of the assets. Many airports do not collect their asset conditions, except those of airfield pavements. All airports have very well-developed pavement condition data in the form of a PCI. Airports collect these data regularly to determine the condition of their runway pavements. Airports need to develop
similar condition assessment procedures for other airport assets. Considering this deficiency, the research team recommends that airports conduct research to develop a comprehensive plan of asset inventory and condition data collection processes for critical airport assets. State DOTs are collecting these data and using these performance measures to prepare a short-term, as well as long-term, maintenance and replacement budget for their highway assets. This research could focus on investigating the inventory data required for various types of airport assets and how to assess their conditions and store them in their database to use for budgeting purposes.
The research team used theoretical processes to determine the deterioration models for most of the airport assets, except runway pavement, to predict their condition in the future with and without delayed scenarios. Therefore, other research could focus on developing the deterioration models of airport assets based on the condition data collected from the case study airport projects. If the condition data of airport assets can be collected for multiple years, then practical models can be developed to predict the condition of these assets in the future. For example, regarding runway pavement, FAA software PAVEAIR can develop regression models to predict the PCI values based on the age and types of the pavement. If similar types of asset deterioration models can be developed for other airport assets, the accuracy of maintenance and replacement budgeting processes can be improved.
For future research, the team suggests investigating the effects of delayed maintenance on air travelers’ user costs. Airports should also consider travel delay costs, airport closure costs, operating costs, and accident costs when calculating the impact of delayed maintenance of airport assets. The magnitude of the effects depends primarily on the size of the airports and the types of assets delayed. It is expected that delaying maintenance of critical airport assets will cause larger disruptions due to the cancellation of flights and increased traveler costs. This also poses the risk of asset failure and potentially increases safety issues as well as replacement costs. The spreadsheet tools should thus be used to quantify the consequence of delaying asset maintenance by considering these impacts, which the team did not include in the spreadsheet tools due to data unavailability.
Research is needed to develop guidelines for airports and address the use of performance-based management strategies in maintenance. Performance-based management approaches help owners collect the performance data of their assets and use them to develop long-term maintenance and replacement budgets. Airports prepare their maintenance and replacement budgets based on traditional methods without considering the performance of their assets. Further research could identify the process and strategies to successfully use the performance data of the assets in developing a long-term maintenance plan. It could also identify the benefits of this method and identify organization structures required to conduct performance-based budgeting.
