## 3 Analysis Process
### Data Analysis
#### 3.1.5 Search 5: Carbon Footprint and Energy Efficiency in Manufacturing  
Findings from the screening conducted using the keywords \"Carbon Footprint and Energy Efficiency in Manufacturing\":  
* **Key Findings:** Energy Efficiency: Optimizing energy consumption plays a critical role in reducing carbon emissions. * **Evolution of Research:** Studies on energy efficiency and carbon management have rapidly increased over the past decade. * **Major Challenges and Opportunities:**
* Challenges: Organizational and economic barriers in implementing energy efficiency practices. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Title** & **Description** & **Sources** \\ \hline Number of & The summaries indicate a significant research interest at the intersection of & \\ Published Articles & “Carbon Footprint”, “Industry 4.0”, and “sustainable manufacturing” over the past decade. A growth rate of 30.77\% was recorded in 1069 documents between 2020 and 2024. & [63] \\ Key Findings & Positive Impacts: Industry 4.0 technologies (Internet of Things, big data analytics, cyber-physical systems) provide resource optimization, waste reduction, and increased production efficiency, reducing the carbon footprint. Challenges: Barriers such as data security, privacy, interoperability, and workforce skills development exist. & [64; 67] \\ Evolution of Research & Research has evolved from conceptual frameworks to practical applications and case studies. Early studies focused on identifying technological trends, while recent research includes case studies validating these frameworks. & [64; 66; 68; 69; 70] \\ Common Methodologies & Systematic Reviews: Used to map existing research and identify gaps. & [68; 69] \\  & Case Studies: Practical applications are used to validate theoretical models. & [64; 66; 70] \\  & Bibliometrics: Used for analyzing publication trends, leading authors, & [63] \\ Major Challenges and Opportunities & Challenges: Issues such as data security, privacy, system integration, and workforce training persist. & [64; 67] \\  & Opportunities: Creating synergies between resource optimization, waste reduction, Industry 4.0, and sustainable development goals. & [64; 65; 66; 71; 72] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of Search 4. Figure 4: Exploring Carbon Footprint Reduction through Industry 4.0 and Sustainable Manufacturing: Trends and Technological Advancements. * Opportunities: Energy efficiency can be enhanced through technological innovations and policy incentives. Table 5 highlights that there is significant interest in improving energy efficiency and reducing carbon emissions, with numerous publications in these fields. Particularly, improving energy efficiency and adopting renewable energy sources stand out as key strategies for reducing the carbon footprint. Research shows that international standards (e.g., ISO 50001) and policy support have shaped the implementation of energy efficiency practices. Common methodologies include systematic literature reviews, data envelopment analysis, and multiple linear regression, which help to understand the relationships between energy efficiency and carbon emissions. Implementation barriers and data deficiencies are cited as the primary challenges to adopting energy efficiency strategies. However, advanced technologies and renewable energy sources present major opportunities in this area. Thus, it provides a comprehensive overview of the research landscape regarding carbon footprint and energy efficiency in manufacturing, highlighting key findings, methodologies, challenges, and opportunities. The key themes of academic studies on energy usage and efficiency and how they relate to research trends are summarized in Figure 5.  
The Systematic Literature Reviews section presents a comprehensive analysis of the existing literature on energy efficiency, while Bibliometric Analysis examines research trends in energy usage and the academic impact of these studies.