Abstract The MAESTRI Total Efficient Framework (MTEF) is a recent holistic concept that congregates four complementary dimensions: Efficiency Framework; IoT Platform; Management System and Industrial Symbiosis. MTEF promotes the development of strategies for continuous performance improvement towards a more sustainable manufacturing. The Efficiency Framework supports the integrated assessment of operations efficiency and eco-efficiency, being measured by a new concept: Total Efficiency Index (TEI). The simultaneous assessment of the environmental, economic and efficiency performance of complex production systems is only possible with a digitalized production system, which is aligned with Industry 4.0 paradigm. Thus, with TEI original dashboards and graphical diagram, both static and dynamic assessments of efficiency vs. eco-efficiency can be analyzed. This paper details the fundaments of the Efficiency Framework and TEI, and presents an application case study from the metalworking sector, where the achieved results are discussed for the new concept validation.