## 3 Materials and Methods  
### Literature Search Strategy  
To identify key parameters influencing TCO, we explored techniques (e.g., statistical and AI) employed in TCO forecasting and systematically examined the advantageous role of AI in forecasting the TCO for CWPs. It provided insights for future research directions to enhance the sustainability and efficiency of CWPs.  
This systematic review adhered to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines [109] to ensure a systematic and reliable approach. The process involved a meticulous literature search, encompassing Scopus and Web of Science (WoS) databases. These databases were selected considering their importance as primary repositories for general scientific literature and citation indexes. In Figure 3, the PRISMA model is shown as a visual guide, outlining the systematic progression of information. It details the stages of identifying, screening, excluding, and including studies, offering specific reasons for each decision.  
Table 1 outlines the search strategies employed to identify suitable studies for inclusion in the review. Search Strategy 1 aimed to identify information on the life cycle and/or ownership costs of chiller plants. In contrast, Search Strategies 2, 3, and 4 adopted a broader approach to ensure a comprehensive review of the literature covering topics such as life cycle cost, ownership cost, operating cost, capital cost, maintenance cost, energy cost, and demand prediction or forecasting or optimization using ML, DL, neural networks, and AI. Combining all four strategies yielded 337 findings across Scopus and WoS. After removing duplicates and non-English articles, the combined unique results yielded 133 articles.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \begin{tabular}{c} **Search** \\ **Strategy No.** \\ \end{tabular} & \begin{tabular}{c} **Boolean** \\ **Operator** \\ \end{tabular} & \begin{tabular}{c} **Term** \\ \end{tabular} & \begin{tabular}{c} **Field** \\ **Scopus** \\ \end{tabular} & \
\begin{tabular}{c} **Web of Science** \\ \end{tabular} \\ \hline \multirow{3}{*}{1} & \multirow{3}{*}{AND} & \multicolumn{2}{c}{chill* AND plant} & \multirow{3}{*}{
\begin{tabular}{c} TITLE-ABSTRACT- \\ KEYWORDS \\ \end{tabular} } \\ \cline{3-3} \cline{5-5}  & & & own OR cost & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Search strategies to identify suitable studies for inclusion in the review.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Search** & **Boolean** & \multirow{2}{*}{**Term**} & \multicolumn{2}{c}{**Field**} \\ \cline{3-4}
**Strategy No.** & **Operator** & & **Scopus** & **Web of Science** \\ \hline \multirow{4}{*}{2} & \multirow{4}{*}{AND} & chill* AND plant & \\ \cline{3-4}  & & \multicolumn{2}{c}{“life cycle cost”} & \multirow{2}{*}{TITLE-ABSTRACT-KEYWORDS} & \\ \cline{3-4}  & & own OR cost & & \\ \cline{3-4}  & & (machine OR deep) AND learning & & \\ \hline \multirow{4}{*}{3} & \multirow{4}{*}{AND} & chill* & \\ \cline{3-4}  & & \multicolumn{2}{c}{“life cycle cost” OR cost} & \\ \cline{3-4}  & & \multicolumn{2}{c}{“life cycle cost” OR timeframe”} & \multirow{2}{*}{TITLE-ABSTRACT-KEYWORDS} & \\ \cline{3-4}  & & learning” OR “