Getting lean transformation right: investigating relationship between external and internal lean practices in Midwest manufacturing companies

Purpose This paper aims to propose and test a comprehensive multidimensional lean implementation model and investigates how external lean practices influence internal practices during a manufacturing firm’s lean transformation. Design/methodology/approach A survey was conducted on 197 managers at multiple manufacturing firms in the Midwestern region of the USA. Data were analyzed using partial least squares-based structural equation modeling. Findings The findings attest to diffusion and adoption intensity of internal lean practices to be significantly higher for the process and equipment operational impact area among Midwest manufacturers; significant positive influence of external lean practices in customer relationships on internal lean practices related to four operational impact areas: process and equipment, production control, new product development and human resource management; significant positive impact of external lean practices in supplier management on internal ones related to three (except work force management) operational impact areas. Originality/value In contrast to unidimensional lean implementation models in literature, the proposed multidimensional lean model recognizes the multifaceted nature of internal and external lean practices and classifies them into six higher order impact areas. To the best of the authors’ knowledge, this is the first study to examine the influence of external lean practices on internal ones based on their operational impact areas individually and not as a single construct.