## 5 Data Analysis
### Pavement Maintenance Performance Expert System  
The expert system developed using eight regression performance models is easy to operate and self-explanatory. The steps to run the program are listed below:  
1. From the MS-DOS prompt, type \"PMPEXP\" and press the <Enter> key. This will start the program, which will show a description screen.
2. To produce a printable text file, press the <Y> key followed by the <Enter> key and then input the file name.
3. Section description: this is an optional field, which may include the road/section name for reference.
4. The following inputs are mandatory to run the program: * Present PCI for the section: This represents the PCI at the start of the analysis. It could be any value between 0 and 100. * Critical PCI value: This represents the minimum allowable PCI value, below which the pavement condition is not allowed to fall. It is used as the main criterion in evaluating the maintenance strategies. It could be any value between 0 and 100. * Analysis Period: this is the period (in years) along which the maintenance strategies are evaluated, and the cost is calculated for each strategy.
5. After the above inputs are entered, the user will be shown the maintenance activities available along with their preset costs. The user will be prompted to change an item's cost if necessary. Next, the user will be introduced to the M&R strategies, which can be suggested by the user. * Maintenance strategy: A maintenance strategy is a combination of the letters: X, A, B, C, P, O, and R, separated by the \"+\" sign. Each strategy represents the sequence of maintenance activities that the user proposes. For example, if the user inputs the following combination: \"C+O+A\", this means that he intends to first carry out the basic routine maintenance (high level) until the pavement condition index falls to or just above the terminal PCI value, and then a structural overlay will be applied; after that, the pavement will be lifted until it reaches the terminal PCI value, and at that time, the basic routine maintenance (low level) will be applied. * The user should enter at least one M&R strategy to continue running the program, and a maximum of five. * The maintenance strategies should be entered using letters separated by the \"+\" sign without any spaces or quotation marks. A maximum of five combinations (letters) is allowed.  
Figure 12: Effect of reconstruction on the deterioration of PCI for high traffic.  
\(\bullet\) Periodic maintenance is not available.  
After entering the M&R strategies, the program will produce the actual strategies that can be implemented throughout the analysis period along with their costs and details.  
The program file to be run is named: \"PMPEXP.EXE\". It reads a configuration file called: \"PMPEXP.CFG\", which must exist in the same directory as the program. The expert system is written in a manner such that the applied maintenance models and initial costs can be changed without any programming effort. The coefficients of the performance curves and initial costs are stored in the configuration file (up to three coefficients, i.e., cubic equation). It must be noted that the format of the configuration file should not be changed to correctly run the program.