The B.U.G.I. uses the first letters of the last names of the engineers who developed this project (Bujnowicz, Ulrych, Grabski, and Iwanicki). The engineers took the concept of the KSUS II medium tank but adjusted the new vehicle to feature a one-turret design. The project was sent for consideration during the Grudziądz conference in 1938–1939. The project was finalized in May 1939 in the Armed Forces Training Center in Modlin. In mid-August 1939, the engineering group presented the vehicle concept and blueprints. However, further development was discontinued due to World War II.