*3.5. Data Driven Analysis for Quantitative Data: Statistical Comparison Analysis*

The statistical comparison analysis was performed on the developed database to explore the current trend in PPM and UPM shown Figures 7 and 8. As can be seen from Figures 7 and 8, the bar charts indicate the annual average numbers, i.e., the five-year trend of PPM and UPM with work order counts (WO) and labor hours (LH) per million square feet (MSF) at eight universities for the years 2015 to 2019.

**Figure 7.** Five-year trend of PPM: (**a**) Work Order Counts; (**b**) Labor Hours.

**Figure 8.** Five-year trend of UPM: (**a**) Work Order Counts; (**b**) Labor Hours.

Comparing the five-year trend of PPM and UPM revealed that, the PPM recorded an average of 3725 work orders, while there was an average of 2491 UPM work orders during the given period. Similarly, the average PPM labor hours were 13,935.5 and the average UPM labor hours were 8487.5. As deterioration of buildings is considered, although the budget for PPM has been increased, it is revealed that the budget for UPM has remained consistent. Therefore, such a finding will be able to utilize as a guideline for facility managers or decision makers to allocate the budget for the PPM and UPM. Figures 9 and 10 illustrate the number of work orders and labor hours at the system level for the entire area maintained. The annual average work order count and labor hours of ten systems were investigated for PPM and UPM.

**Figure 9.** System-level comparison of the PPM: (**a**) Work Order Counts; (**b**) Labor Hours.

**Figure 10.** System-level comparison of the UPM: (**a**) Work Order Counts; (**b**) Labor Hours.

As can be seen from Figures 9 and 10, HVAC was identified as the most significant system resulting in the highest number of work orders and labor hours every year, followed by electrical, fire protection, and plumbing systems in the PPM, while the HVAC system again was identified as the most critical system resulting in the highest number of work orders and labor hours, followed by plumbing, and electrical systems in the UPM. Although work order counts for the top two systems are similar, HVAC (4874) and plumbing (4870), HVAC consumed significantly higher number of labor hours in both PPM and UPM. Additionally, interior construction, interior finishes, and furnishings are also identified to be on the higher side compared to PPM whereas conveying systems and exterior enclosure generated lower UPM work orders.
