## 4 Discussion
### Rq.1.--What is the trend and actual situation of LSS applied to manufacturing chemicals? To examine the current trend and state of LSS applied to the manufacturing of chemicals, it was essential to first analyze LSS adoption in all environments and then assess its role within this specific context. The results indicate that the application of LSS has gained significant interest and recognition within the research community since its origin in the early 2000s. Particularly, the implementation of LSS in the manufacturing sector is steadily growing, with approximately 50% of the total publications on this topic published within the last five years (see Figure 5). However, its implementation in the manufacturing of chemicals does not follow this positive tendency. In fact, the publication trend on this topic is negative, with four publications in the last five years and only one in the last year. Additionally, the contribution is quite low in comparison to the adoption of LSS in other manufacturing sectors (see Figure 6). This comparatively low volume of publications, along with the negative publication trend, emphasizes the need for further research to explore new opportunities and revitalize interest and engagement in LSS within the chemical manufacturing domain. This was the motivation for conducting the present research. Rq.2.--What are the motivations or factors driving the adoption of LSS in the chemical manufacturing sector? Several factors drive the adoption of LSS in the chemical manufacturing sector. These drivers have been identified from the analysis of 22 studies on this topic (Table 10). Some of the key drivers highlighted in these papers include the following:  
* Cost reduction: LSS implementation led to significant cost savings [51, 52, 59, 61, 66, 69]. * Quality improvement: LSS enhanced product and service quality and customer satisfaction [55, 57, 70]. * Cycle time reduction: LSS helped streamline processes, eliminate non-value-added activities, and optimize workflows [61, 69]. * Increased production capacity: LSS techniques optimized resource utilization, eliminated bottlenecks, and enhanced workforce productivity [51, 58, 59, 69, 70]. * Regulatory compliance and risk mitigation: These companies operate in a heavily regulated environment, subject to stringent safety and environmental standards. LSS has provided structured approaches and tools to streamline processes and ensure compliance with regulatory requirements. Additionally, LSS methodologies have helped identify and address potential risks and vulnerabilities within manufacturing processes [36, 38, 42, 44, 46, 47, 48, 49]. * Sustainability and environmental management: The chemical industry is increasingly focusing on sustainable practices and minimizing its environmental footprint. LSS offers techniques for waste reduction, energy efficiency, and sustainable process design, aligning with the industry's sustainability goals [52, 53, 54, 63]. * Continuous learning and innovation: LSS encourages a culture of continuous learning, problem-solving, and innovation. Chemical manufacturers adopting LSS embrace a mindset of ongoing improvement and foster a culture of employee involvement and engagement in driving innovation and process enhancement [32; 56; 57; 70]. Other factors have also been observed in the implementation of LSS in the chemical manufacturing sector (see Table 10 above). Waste identification and employee morale are some examples. R.Q. 3.--What factors contribute to the limited adoption of LSS by chemical manufacturing companies? Firstly, the lack of technical knowledge or insufficient understanding of LSS is probably the main barrier to its implementation. It requires a certain level of expertise and familiarity with the methodologies, tools, and techniques associated with LSS. This is even more vital in the manufacturing of chemical products, where complex processes and strict regulatory requirements are involved.