Since 2001, TEI has adopted lean manufacturing understanding to be a more flexible and faster company having strong reflexes. Adopting cellular manufacturing as a necessity Since 2001, TEI has adopted lean manufacturing understanding to be a more flexible and faster company having strong reflexes. Adopting cellular manufacturing as a necessity of manufacturing and product technology, TEI develops its skills by means of lean cells. In this journey, TEI not only improves manufacturing areas and but also realizes lean principles in office activities.