2025-05-192025-05-192025-04-21Ávila-Gutiérrez, M.J., Córdoba-Roldán, A., Morato Huerta, P. y Lama-Ruiz, J.R. (2025). Modernizing Small and Medium-Sized Enterprises: A Lean Audit Model for Digital Integration. Systems, 13 (4), 304. https://doi.org/10.3390/systems13040304.2079-8954https://hdl.handle.net/11441/172871This study proposes an audit model to modernize artisanal manufacturing companies and facilitate their transition to Industry 4.0. Based on Lean Manufacturing, Lean Thinking, and Lean Management principles, the model enhances operational efficiency and competitiveness while considering the resource constraints of Small and Medium-Sized Enterprises (SMEs). It provides a structured approach to identifying key improvement areas and guiding digital transformation. The research follows a four-phase methodology: (1) a company assessment questionnaire to diagnose the current state, (2) a method matrix to analyze improvement strategies, (3) a dimension map to structure key transformation areas, and (4) prioritization of improvement dimensions to define a tailored action plan. A case study in an SME validated its applicability. Findings show that the model helps identify critical improvement factors and implement targeted Lean interventions, enhancing Industry 4.0 readiness. It enables a progressive adoption of digital enablers while optimizing traditional manufacturing processes. The originality of this study lies in its integrated auditing framework, structured around four dimensions and twelve key factors. It introduces a 48-question assessment tool, methods matrices, and prioritization mechanisms. Additionally, it defines four strategic development stages—Readiness, Start-up, In-transition, and Advanced—providing a roadmap for continuous improvement in SMEs.application/pdf30 p.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/FrameworkAudit practicesLean manufacturingIndustry 4.0Small and Medium-Sized Enterpriseinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess10.3390/systems13040304