# Airport pavement Maintenance Decision-Making System with Condition Cases Optimization
## 2 Airport Pavement Management System Architecture
### Decision Making Process for Airport Pavement Management System  
#### 2.4.1 Determination of Cost and Effect for M&R Methods  
For the stable and efficient operation of a pavement management system (PMS), it is crucial to quantify the costs and benefits of alternative maintenance methods and establish selection criteria [26]. The determination of pavement methods and costs was informed by domestic and international cases, including reports from agencies like the Minnesota Department of Transportation [27] and the Airport Cooperative Research Program (ACRP) [28], and academic papers such as [PERSON] [29], [PERSON] [30], and [PERSON] [31]. Additionally, references were made to maintenance manuals from the Korea Expressway Corporation [32] and the Korea Airports Corporation [33].  
Pavement maintenance methods are generally categorized into preventive maintenance, major rehabilitation, and reconstruction [11]. Among the major rehabilitation methods applied to Korean airport flexible pavements, 62% were 7.5 cm milling and overlay, 10% were 5 cm thin milling and overlay, and 14% were 10 cm to 25 cm milling and overlay [34]. To evaluate the effectiveness of various methods used for highway, this study selected resurfacing, partial repair, mill and overlay by thickness, patching, slurry sealing, fog sealing, and crack maintenance, as alternatives.  
While primarily referring to the Korea Airports Corporation's data, for methods with limited case studies, practical costs were determined by assigning higher weights to data from the Korea Expressway Corporation and the ACRP. The costs of other methods were distributed based on the least expensive method, crack maintenance (USD 2.35/m2), and the most expensive method, reconstruction (USD 105.75/m2), as references. Preventive maintenance aims to extend the expected service life of the pavement, so the immediate recovery of the pavement condition is minimal. Through consultations with researchers from the Korea Expressway Corporation, the study assigned lifespan extension effects of 3.5 years, 4 years, 3 years, and 2 years, for patching, slurry sealing, fog sealing, and crack maintenance, respectively. For major rehabilitation methods like milling and overlay, it was assumed that the pavement condition increased to 95, and the expected service life extended up to 10 years. Thickness criteria of 5 cm, 7.5 cm, and 15 cm were selected for milling and overlay based on Korean pavement evaluation data. Resurfacing was assumed to fully restore the pavement's structural capacity, resulting in an SL recovery level of 100 and an extended service life of 30 years. During reconstruction implementation, it was considered that the affected section would be closed for 3 years, but the pavement condition would be maintained to prevent negativity for benefit calculation. Furthermore, it was assumed that as the number of applications accumulated, the expected lifespan extension effect diminished in a 5:3:2 ratio [35]. Cost and effect of the M&R methods by each alternative are presented in Table 1 below.