The current context of the plastic manufacturing sector has suffered a significant alteration in recent years due to external factors such as the pandemic caused by Covid-19. On the other hand, at the national level it has been detected that 64% of companies use only between 61% and 70% of their installed capacity. In addition, the sector's profitability has fallen by 3% in the last 8 years. In this sense, this research work took as a case study an SME in the plastic sector to determine the leading causes directly related to efficiency and productivity problems. Such causes have resulted in the delayed of delivering orders, consequently lowering profitability; the reversal of loss has been the main incentive of this work. By understanding the roots of the problem, we propose the development of a double-focus optimization model that values both the operational improvement and the working conditions, such as team spirit that motivate the actions of the collaborators. This model utilizes tools corresponding to the Lean andSystematic LayoutPlanning (SLP)methodology. Moreover, the novelty of this proposal is the integration of a sustainability phase with a focus on continuous improvement over time by incorporating these tools as part of the company's routine. Finally, some of the main results obtained from this research were an increase of the order fulfillment index by 13.4%, a reduction of the effort of the operators by 62%, a decrease of the set-up time by 57%, and an increase of the Overall EquipmentEffectiveness (OEE) by7%.