## 2 Lean and Green Overview
### Industries Application of Lean and Green
#### 2.1.2 The Petroleum Industry  
Lean and green manufacturing has emerged as a good approach. The relationship between the two paradigms has been investigated in various literature, such as [33; 46]. These studies highlight the reduced waste achieved through the complementary roles of both paradigms. Studies have demonstrated that certain petroleum companies in developed countries have implemented lean and green practices in their operations, leading to an increase in operational efficiency and reduced environmental footprint.  
Table 1 demonstrates how the petroleum business has significantly increased sustainability by successfully integrating lean and green principles.  
The petroleum industry is gradually reducing its carbon footprint through technological advancement, integrating renewable energy, and enhancing the overall value chain energy efficiency as lean and green is implemented. Moreover, it is essential to highlight that the traditional approach to petroleum refining, among other petroleum production processes, has evolved with the improvements that new technologies have provided [59]. These evolved petroleum refining approaches include molecular, catalysis, and digitalization [60; 61; 62]. Besides these, new technologies can improve the refining efficiency, effectiveness, and quality of desired products [61; 62]. Moreover, the evolved petroleum refining approaches could present implementation challenges in SSA, such as significant investment costs, adapting to existing refineries, and required expertise. Despite the previously stated potential, the challenges highlighted present an obstacle to using SSA petroleum [59; 63]. Furthermore, utilizing the petroleum industry supply chain illustrated in Table 2 and Figure 1, the value chain with possible green initiatives in the petroleum production process is demonstrated. It can be observed that there were about five enumerated means of green initiatives within the processes in the supply chain in Figure 1.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Company Name** & **Practice** & **Results** \\ \hline \multirow{3}{*}{Shell (UK)} & Implemented a closed-loop water recycling system in their fracking operation and invested in carbon capture and storage [47]. & Minimized water usage and wastewater disposal and reduced greenhouse gas. \\ \hline \multirow{3}{*}{Chevron (USA)} & Implemented advanced analytics and automation methods to monitor operations [48; 49; 50]. & Reduced the operational waste and environmental impact of drilling operations. \\ \hline \multirow{3}{*}{Total (France)} & Installed energy-efficient equipment and renewable energy sources [48]. & Reduction in carbon footprint, energy consumption, and emissions. \\ \hline \multirow{3}{*}{Statoil (Norway)} & Invested in innovative technologies like gas compression for capturing and utilization [51; 52]. & Reduced greenhouse gas and maximized resource utilization. \\ \hline \multirow{3}{*}{BP (UK)} & Invested in renewable energy sources such as wind and solar power and infrastructure for electric charging vehicles [48; 53]. & Reduced emission and improved energy performance. \\ \hline \multirow{2}{*}{Aramco (Saudi Arabia)} & Invested in carbon capture and storage technologies [54; 55; 56]. & Reduction in greenhouse gas emissions. \\ \hline \multirow{2}{*}{Petrobras (Brazil)} & Improved drilling efficiency using real-time monitoring and data analytics [57; 58]. & Reduction in environmental waste. \\ \hline \hline \end{tabular}
\end{table}
Table 1: Lean and green case study.