## 4 Results
### Results of CII and FMEA  
The CII results were obtained by multiplying the CSI and standardized weights (a\({}_{\text{i}}\)), which contained the satisfaction and importance results and indicated the priority of improvement. The results of the CII in Table 6 show that the first five attributes that should be considered as priority improvements were safety in boarding and disembarking from the bus (1), bus attendants' attitudes and helpfulness (4), cleanliness of vehicles (5), security against crimes on buses and at stops (7), and punctuality of buses according to the schedule (11). These five attributes have relatively higher values for the CII, which indicated that these attributes contributed significantly to the satisfaction level and are currently rated low but are important to passengers. These attributes originated from the interaction with passengers, tangible service equipment, and operating management support dimensions. They were highly important and could satisfy customers, so this showed those attributes with a higher priority that should be enhanced. This study applied an FMEA to evaluate Bangkok bus service risk. The service quality risk analysis of the Bangkok bus service is shown in Table 6. According to the results, safety in boarding and disembarking from the bus (1), bus attendants' attitudes and helpfulness (4), cleanliness of vehicles (5), security against crimes on buses and at stops (7), and punctuality of buses according to the schedule (11) were the top five attributes that had a high value for Cr, which meant that these attributes had a high service quality risk. Among these five attributes, safety in boarding and disembarking from the bus (1) had the highest value for Cr. Additionally, the CII value for this attribute was relatively high, indicating that it had a significant impact on customer satisfaction, and service failures related to this attribute occurred frequently. This result was consistent with the Kano's model classification of this attribute as a one-dimensional quality (O) attribute, meaning that the greater the level of fulfillment of this attribute, the greater the level of customer satisfaction. Buses in Bangkok frequently stop in the middle of the road for passengers to board and alight, posing a potential danger when the road is congested and there are no designated bus stops or waiting areas for passengers. In addition, some bus drivers may not follow safety procedures or regulations such as not coming to a complete stop before opening the doors or not waiting for passengers to safely board or alight from the  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Attributes** & **CSI** & **Standardized Weight (a\({}_{\text{i}}\))** & **CII** & **Oc** & **Cr** & **Cr Ranking** \\ \hline Item 1 & 0.73 & 1.000 & 0.73 & 0.46 & 0.97 & 1 \\ Item 2 & 0.65 & 0.250 & 0.16 & 0.26 & 0.76 & 10 \\ Item 3 & 0.59 & 0.333 & 0.20 & 0.34 & 0.84 & 9 \\ Item 4 & 0.66 & 0.750  
bus. Therefore, the bus company should consider this attribute as a priority improvement because it can increase commuters' satisfaction after service quality improvement. Apart from the safety in boarding and disembarking from the bus (1) on which the bus company should be focusing, cleanliness of vehicles (5) and punctuality of buses according to the schedule (11) were also important attributes that had a large contribution toward commuters' satisfaction, especially punctuality. Cleanliness is often seen as a basic requirement for a transportation service. This result indicated that the respondents were dissatisfied with the level of cleanliness of buses in Bangkok and that the vehicles are frequently found to be insufficiently clean. Moreover, as people value public transport reliability (e.g., frequency, punctuality, and transfer) over convenience, punctuality is an important quality indicator for commuters in choosing a particular mode of transport [67; 68]. There are several researchers who found that punctuality is one of the major concerns among the respondents in public transport [68; 69; 70].