## 7 Conclusions  
The United Nations created the Sustainable Development Goals in 2015. To achieve these goals, an increasing number of educational institutions and researchers are striving to introduce SS to the production and manufacturing industries. However, few studies have generated a deeper discussion on the balance relationship of the three dimensions of economy, the environment and society in practicing SS. This factor has caused deviation in the theoretical application of SS. To further promote understanding of the concept of the SS, this study proposed an ISS-AFLCSS according to a real-world case to analyse the mutual influence relationship in the three dimensions of the SS. The analysis and discussion results confirm that the concept of SS can be further understood by fully considering the interrelationship of the three dimensions to balance development.  
This study makes three contributions. First, this study thoroughly analyzed and discussed a balanced relationship in the three dimensions of the SS. Second, this study proposed a hybrid method using an improved GA to optimise multiple objectives of scenarios and adopting the TOPSIS method with AHP to optimise and select an optimal scenario according to the corresponding time windows. Third, the research results confirm that the established ISS-AFLCSS is able to provide a set of the best-ideal scheduling scenarios under the conditions of different electricity utilisation strategies for Chengsteel to achieve balanced economic, environmental and social development.  
Although this research strives to fill the gaps of previous studies, there are still some limitations. Because of space limitations, this study only discusses the three dimensions of economic, environmental and social indicators of SS and lacks index evaluation. In addition, we made a sensitivity analysis in terms of the number of vehicles, and the change in number would affect the weight in AHP. However, we didn't make other types of sensitivity analysis. In the next step of research in this field, this study will generate a further analysis of these issues. On the other hand, the iron and steel industry is characterised by high energy consumption and high pollution gas emissions. According to reports, 52% of energy consumption and 36% of pollution gas emissions in industrial processes are attributed to manufacturing activities [11; 41]. Therefore, the iron and steel industry has great potential to deducing energy consumption and pollution gas emissions, and this study hopes that all parts of society pay more attention to this field to strive to accelerate the goals of the 2030 Agenda.  
Methodology, B.Q.; Investigation, B.Q.; Data curation, S.L. and K.-J.W.; Writing--original draft, B.Q. and S.L.; Writing--review & editing, K.-J.W. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
Data Availability Statement: Based on request.  
Conflicts of Interest: The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Criteria Layer** & **Economic Benefit** & **Environment Benefit** & **Social Benefit** & \(\mathbf{w}\) \\ \hline Economic Benefit & 1 & 2 & 2 \\ Environmental Benefit & \(1/2\) & 1 & 2 \\ Social Benefit & \(1/2\) & 1/2 & 1 \\ Sum & 2.00 & 3.50 & 5.00 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Judge matrix of criteria without consideration of peak to valley.