## 2 The Process Plant Inspection and Maintenance System
### Literature Review Summary
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Improving Method** & **Methods** & **Description** & \begin{tabular}{c} **Research/Knowledge** \\ **Gaps** \\ \end{tabular} & **Journal Articles** \\ \hline Survey Questionnaire & Questionnaire-based approach & Questionnaire-based & \begin{tabular}{c} More research is \\ needed to determine \\ the most effective \\ survey design and to \\ questionnaire to \\ identify the underlying \\ causes of maintenance \\ issues and to collect \\ potential solutions \\ from stakeholders \\ \end{tabular} & \
\begin{tabular}{c} **Journal Articles** \\ \end{tabular} \\  & &
\begin{tabular}{c} Monte research is \\ needed to determine \\ the most effective \\ survey design and to \\ validate the results \\ against other data \\ sources. Additionally, \\ more research is \\ needed to investigate \\ the impact of cultural \\ values on ethics and \\ conflict management \\ during TAM. \\ More research is \\ needed to compare the \\ effectiveness of \\ different assessment \\ tools and to determine \\ the most appropriate \\ tool for different types \\ of maintenance \\ strategies. \\ Additionally, more \\ research is needed to \\ investigate the impact \\ of new workers and \\ transient teams on \\ communication gaps, \\ idling workers, and \\ spare part shortages \\ during TAM. \\ More research is \\ needed to evaluate the \\ usability and \\ effectiveness of the \\ software tools, and to \\ determine their impact \\ on maintenance \\ outcomes. \\ Additionally, more \\ research is needed to \\ investigate the use of \\ technology-based \\ solutions for \\ automating tasks and \\ increasing maintenance \\ efficiency. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Summary of plant maintenance studies by researchers. Figure 4 presents a visual representation of the distribution of research objectives among the studies reviewed in this literature review. The chart shows the percentage of studies that focused on various research objectives, including reducing the duration of the TAM, extending examination intervals, defining TAM strategies, determining optimal turnaround intervals, mitigating production loss, evaluating TA performance, and reducing TA costs. The chart reveals that the dominant themes among the studies were centered on reducing the TAM duration and extending examination intervals. Approximately 28% of the studies aimed to reduce the duration of TAM, emphasizing the importance of minimizing operational downtime and improving efficiency. For example, [PERSON] et al. [20] explored over 80 pieces of literature to unravel trends and optimize TAM strategies with the goal of curtailing duration, human resources, and costs. Similarly, [PERSON] et al. [40] probed the role of risk management in ensuring the success of plant turnarounds using a questionnaire-based approach, highlighting the direct link between effective shutdown risk management and avoidance of considerable cost and time overruns. Another 11% of the studies focused on extending examination intervals, which can help identify potential issues earlier and reduce the likelihood of unplanned downtime. For instance, [PERSON] [60] highlighted the benefits of RBI for assessing aboveground storage tanks and process piping in petrochemical plants, focusing on the risks, incident consequences, and probability. This approach optimizes inspection resources, maximizes efficiency, and ensures resource allocation by prioritizing high-risk components. The remaining research objectives represented in Figure 4 include defining TAM strategies, determining optimal turnaround intervals (9%), mitigating production loss, evaluating TA performance (7%), and reducing TA costs (3%). For example, [PERSON] et al. [1] expanded the scope of improvement for contractors and plant owners during TAM by using a decision matrix. Their study revealed that auxiliary activities, including preparation, transportation, and material handling, absorbed substantial on-site work hours.