Although small and medium-sized enterprises (SMEs) shape the cornerstone of economy, they encounter various challenges in transitioning to Industry 4.0. This issue represents an ill-structured problem under uncertainty, which requires a specific set of tools to be solved. This study relied on a hybrid method composed of the interval type-2 fuzzy BWM (IT2F-BWM) and the interval type-2 fuzzy DEMATEL (IT2F-DEMATEL) method, to handle the complexities that SMEs experience in transitioning to Industry 4.0. The results of the IT2F-BWM revealed the importance of the “organizational” criterion, in comparison to “technological” and “strategic” criteria. Furthermore, the IT2F-DEMATEL results showed that the “organizational” dimension exerted the highest degree of influence. The most effective criteria (sub-dimensions) were “a lack of skillful management team”, “the need for advanced skills”, and “having insufficient knowledge of and little interest in Industry 4.0 and its outcomes”, which fell under “organizational”, “technological”, and “strategic” dimensions, respectively. The findings could help firms and enterprises to gain adequate knowledge of Industry 4.0 before implementing it, while clarifying how such entities can enhance their organizations and overcome obstacles by training their human resources.