Abstract
Enterprises employing an Engineer-to-Order (ETO) manufacturing strategy produce complex products designed specifically to customer requirements, on a project basis, under time and cost constraints. As a result of this complexity, wastes and inefficiency occur within the internal and external supply chain. To improve productivity, companies are striving to implement Lean practices in ETO environments but encounter implementation barriers. Based on the comprehensive literature study on Lean implementation barriers in ETO companies, this study empirically validates the occurrence of these barriers in practice. For this purpose, empirical evidence was gathered using a survey questionnaire followed by semi-structured interviews with 15 companies from the ETO sector in construction, mechanical engineering, and shipbuilding. As a result, the barriers mentioned in the literature are compared with the barriers that occur in practice. Simultaneously, new barriers not described in the literature are also identified. This study can guide Lean professionals in the ETO environment in their Lean efforts to identify corresponding barriers in their own organizations while trying to understand the relevant causes and fields of action to mitigate them. Future research should aim to explore other methods and strategies along with emerging technologies of Industry 4.0 that could help overcome Lean implementation barriers.