The complex pathways to social sustainability: Quantifying the effects of Kaizen and Gemba in the maquiladora industry

• Kaizen significantly strengthens both Gemba practices and social sustainability. • Gemba displays a curvilinear path: initial drawbacks, then positive social impact. • Heterogeneous patterns found: exponential (KAI–GEM), linear (KAI–SOSU), curvilinear (GEM–SOSU). • Few maquiladoras (7.9–9.2 %) achieve high implementation across multiple dimensions. • Findings guide differentiated strategies linking CI practices to social sustainability. This study empirically examines the interrelationships among Kaizen (KAI), Gemba (GEM), and Social Sustainability (SOSU) in the Mexican maquiladora industry, addressing a gap in the literature on how continuous improvement programs support sustainability in the manufacturing industry. The variables are related through three hypotheses that are validated using a structural equation model evaluated with a partial least squares approach (PLS-SEM) and validated with data from 240 responses to a questionnaire administered to industrial professionals. The results confirm the hypotheses, revealing that KAI positively influences GEM (β=0.667, p < 0.001) and SOSU (β=0.287, p < 0.001), whereas GEM exerts a positive effect on SOSU through a curvilinear relationship that transitions from negative impacts at low levels of implementation to positive ones at advanced levels. The heterogeneous nature of these relationships-exponential between KAI-GEM, linear between KAI-SOSU and curvilinear between GEM and SOSU–reveals distinct mechanisms that require specific implementation strategies. In addition, a sensitivity analysis is reported, which indicates that only a minority of organizations (7.9–9.2 %) simultaneously achieve high levels of implementation in multiple dimensions, evidencing the potential for competitive differentiation inherent in the effective integration of these methodologies as pillars of SOSU.