Purpose – The purpose of this paper is to propose an assessment approach to evaluate the organizationalcapabilities to deploy a Lean Six Sigma (LSS) strategy.Design/methodology/approach – Based on a comprehensive literature review, critical success factorsrequired to deploy LSS were defined. These key factors are evaluated by a questionnaire based on maturitygrids and structured as a multi-criteria model to compute a potential LSS performance indicator. Thisapproach is illustrated through two case studies.Findings – To promote a successful implementation of LSS in SMEs, it is necessary to consider five maincritical factors. The evaluation of these factors could be achieved thanks to a multi-criterion-based maturityindicator for the LSS implementation. The case studies show that this approach allows SMEs to understandtheir strengths and weaknesses and thus better prepare the implementation of LSS.Research limitations/implications – The proposed tool identifies characteristics of companies leading tosuccessful LSS implementation; but is not yet able to provide a detailed strategy to improve them. The case studieswere applied tomanufacturing companies; therefore, there is no evidence of conclusions in the context of services.Practical implications – The proposed methodology will help managers and practitioners to evaluate thereadiness level of a company to implement LSS. Then, they could estimate the effort required to achieve theLSS deployment.Originality/value – This paper proposes a new metric of the capacity to implement the LSS successfullyin SMEs: the Lean Six Sigma Global Index. This indicator is based on a survey completed by managers andsupported by observable phenomena to establish a tailored diagnosis before the LSS implementation.