## 6 Experiment Result  
A building's plumbing system is so complicated that it is often difficult for a non-professional to maintain and operate. The goal of this experiment was to assist users with different knowledge backgrounds to perform basic equipment operation and maintenance in urgent problem-solving situation using BARMS. Students of various educational backgrounds were randomly selected to participate in this experiment as testers and fill out questionnaires. In total, six doctoral students and nine master's students participated in this study, with the educational backgrounds in architecture, information engineering, and design.  
The test results demonstrated that the testers who used BARMS could find the correct power switch and cooling tower that connected to the leaking pipe, and shut down the valve correctly (Figure 6). Unanimously, the testers stated that maintenance efficiency could be improved in low illumination environments by utilizing BARMS.  
Screen shots of BARMS utilization are shown in Figure 7. Upon running the app, all of the regional pipes were displayed, including in-wall and downward-extending ones. The pipes were marked by 3D numbers, such as A9, A10, or A11. The tester could tap on a certain pipe number to hide unrelated pipe information. Meanwhile, the location of the power switch connected to the cooling tower and pump was indicated by a moving 3D arrow to attract the tester's attention. After turning off the power switch, the tester could walk to the corresponding cooling tower and valve by following the safe maintenance route displayed on the screen. Moreover, tapping the \"Maintenance Animation\" button would bring up an animated arrow around the valve showing the correct rotation direction to shut down the pump. A video sample of the test can be seen in Appendix A.  
Figure 6: BARMS tested by a student in darkness.  
Figure 7: Smartphone screenshots of BARMS utilization.  
The questionnaire was revised on the basis of the Post-Study System Usability Questionnaire (PSSUQ) (Appendix B). The PSSUQ has four dimensions with a total of 16 assessment items, including 1-16 items for the \"overall average\", 1-6 items for \"system usefulness\", 7-12 items for \"information quality\", and 13-15 items for \"interface quality\" (Table 1). The questionnaire items were scored on a Likert-type seven-point scale, where 1, 2, 3, 4, 5, 6, and 7 were represented by \"strongly agree\", \"agree\", \"somewhat agree\", \"neutral\", \"somewhat disagree\", \"disagree\", and \"strongly disagree\", respectively. Essentially, the lower the rating the higher the system's reported usability. Table 1 shows the feedback from the PSSUQ. The overall average, system usefulness, information quality, and interface quality scores were 1.74, 1.42, 1.90, and 2.00, respectively, showing high system usability [28]. Figure 8 shows more detailed scoring. Questions 7 and 8 scored relatively high because BARMS did not provide a way to correct system errors. Although there were no obvious errors in the system during the test, it was a function that the testers thought could be provided in the future. Other suggestions included adding more text to instruct the user's actions and more screen buttons for system options.