In the context of a global competitive environment, industrial companies have to pursue continuous performance improvement, leading to the popularity of Lean Manufacturing throughout the world. Overall equipment effectiveness (OEE) is considered the relevant performance measurement tool, which is able to take into account a machine's availability, performance and quality. Therefore, many firms have attempted to introduce this tool in their industrial units.This article consists of a study of the OEE metric application range in real manufacturing lines, to develop an understanding of the related challenges for production managers, financial controllers and companies.