A computer implemented method of operating a video management system, the method comprising inputting, into the video management system, a plurality of virtual video streams generated by virtual video cameras within a dynamic 3D virtual environment; receiving, in the computer, at least one command from a user indicative of an instruction to alter a functioning of the dynamic 3D virtual environment and/or a functioning of the video management system; and displaying on a display, from the video management system, at least one virtual video stream and/or at least one alert, alarm and/or message implementing at least one alteration caused by the received command.