Lean Six Sigma (LSS) has been driving many organizations around the world, enhancing their business through quality and performance improvement. Several studies point out the results expected from the LSS approach depend on successful implementations. Although there are some frameworks that guide organizations through the implementation process, few studies consider the specifics of Engineer-to-Order (ETO) production systems. This master dissertation proposes to fill this gap by developing an implementation framework developed in Action Research. For this, a hybrid maturity model was used, whose main parameters are the Critical Success Factors (CSF). The model and parameters were identified and explored in the literature through Scoping Reviews. To reflect and evaluate the ETO context, these parameters were validated, structured and weighted by focus groups with experts using Item-Objective Congruence (IOC), Analytic Hierarchy Process (AHP) methods and Fleiss Kappa statistic. Next, a Research-Action was conducted within a media sector company, pursuing the check-action-plan-do (CAPDo) cycle. As a result, the organization directed its continuous improvement efforts, resulting in a rapid increase in maturity level. This exploratory research gave rise to a framework presented as an LSS implementation guide for ETO organizations. Some opportunities for improvement and limitations, such as the subjectivity of the assessment tool and the need for further practical applications, which require time, are inquired as improvement suggestions for future research.