Summary: The necessity of an energy supplier was to solve an impact problem presented at the damper winding ring or short-circuit ring of a 625 kVA generator and to redesign a fan for it. The principal restriction was the time. It should be done in 15 calendar days, working with drawings of the machine, operational data and from specifications, taking measures from the real machine during just one day while the machine’s maintenance began in order to solve the impact problem which real cause was not found yet. The answer was found working with the concept of simplified virtual laboratory (SVL) using finite elements analysis (FEA) and failure analysis from visual inspection. A fast and effective method which combines simplified 2D computational fluid dynamics (CFD) Models and analytical formulation from electrical machines bibliography allowing time and money saving is shown.