Modern day diesel engines use systems like Exhaust Gas Recirculation (EGR), Variable Geometric Turbo Charger (VGT), inlet throttle for air regulation, multiple injection strategies, high pressure rail systems for fuel regulation to optimize the combustion for meeting the strict emission and fuel consumption demands. Torque based ECU structures which are commonly used for diesel engines require a large amount of calibration work. Conventional manual methods for emission and fuel consumption optimization (Full factorial or Line search method) results in increased test bed usage and it is almost impossible to use these methods as the number of parameters to optimize are very high. The conventional DoE tests have been limited by the necessity of calibration engineer’s expertise and manual prescreening of test points to be within thermal & mechanical limits of engine systems. This subsequently leads to excessive screening of variables; which is time consuming. Moreover, model output quality is also badly affected as measurement points are missing in relevant areas.At the Engine Development Center of TATA Motors, together with AVL List GmbH, a pilot project was initiated to overcome aforesaid limitations with a new Online DoE process called Global COR iDoE to calibrate several power ratings of an engine. In this approach, the DoE is applied to produce incremental improvements in designs and at the same time models are evolved in parallel for the ongoing experiment, which also improve while more and more data points are measured.