# Overall Equipment Effectiveness: Systematic Literature Review and Overview of Different Approaches
## 3 Results
As presented above, the OEE was modified to solve gaps in various issues, such as sustainability, human factor, transport, manufacturing system, mining, cost, port and resources. RQ (3). Which are the principal contributions in OEE and what are the future trends? \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Author** & **Year** & **Model Name** & **Brief Description** \\ \hline
[184] & 2016 & Stochastic shovel effectiveness & Quantifies performance effectiveness of electric and hydraulic shovels. \\ \hline
[185] & 2017 & OEE of BELT equipment & Bucket-based excavating, loading and transport (BELT) including all equipment comprising a bucket, e.g., draglines, shovels, load-haul-dumps and trucks. \\ \hline
[186] & 2017 & Strategic equipment effectiveness & A global measure of the effectiveness of an integrated electrical system. \\  & & Operational equipment effectiveness & Identifies and ranks decision-making-units in terms of efficiency. \\ \hline
[187] & 2017 & Overall machinery effectiveness & Identifies and ranks decision-making-units in terms of efficiency. \\ \hline
[18] & 2017 & OEE of port terminal & Identifies the most efficient terminal, addressing either manageable or unmanageable factors. \\ \hline
[188] & 2017 & Modified OEE & Includes losses associated with human factors and usability (the frequency of setup and changeover process) \\ \hline
[189] & 2018 & Extended overall equipment effectiveness & Evaluates the entire process considering human resources and equipment Performance. It is applied in medicals activities of operating rooms. \\ \hline
[17] & 2018 & OEE to transport management & Improves efficiency in road transport by adapting OEE to transport management. \\ \hline
[11] & 2018 & Modified OEE & Optimizes the effectiveness of urban freight transportation. \\ \hline
[190] & 2018 & Overall material usage effectiveness & Measures material usage effectiveness and identifies material loss in the manufacturing process. \\ \hline
[191] & 2018 & Sustainable overall throughputability effectiveness & Includes sustainability criteria and can be used in the system lifecycle. \\ \hline
[7] & 2019 & Overall task effectiveness & Analyses and evaluates losses related to manual assembly tasks. \\ \hline
[192] & 2019 & Modified OEE & Improves the effectiveness of scheduling jobs with earliness/tardiness. \\ \hline
[193] & 2019 & OEE–TCQ & Improves the process approach in maintenance in terms of time, cost and quality. \\ \hline
[194] & 2019 & Overall effectiveness & Adapted for mining production to examine the effectiveness of the mining machine. \\ \hline
[195] & 2019 & Standalone OEE & Identifies system bottleneck and excludes effects from upstream and downstream. \\ \hline
[196] & 2019 & Modified OEE & Calculates the OEE in serial, parallel and combined machine systems in the production line. \\ \hline
[197] & 2019 & Modified OEE & Includes a term that considers material utilization. \\ \hline
[198] & 2019 & Overall substation effectiveness & Measures substation performances and indicates the overall maintenance performances. \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._Initially, OEE was used in production, in particular for TPM, which assists in identifying the overall equipment performance in a manufacturing process [199]. To accommodate industry needs, some researchers began to analyze the productivity of manufacturing line systems [6; 13] or factories [174]. Currently, OEE is used with continuous improvement methodologies, such as lean manufacturing to increase productivity by eliminating waste [200]. It is also used as a KPI and data collection tool to measure the effectivity and process capability of new six sigma implementations [61]. Following the methodology of continuous improvement, [PERSON] et al. (2019) [7] developed a new metric based on OEE, known as overall task effectiveness. This new indicator supports lean and six sigma methodologies to identify, analyze and evaluate losses that occur during manual assembly activities.