An assignment system and method determine time-variable risk profiles for separate vehicle systems that are remotely controlled by operators located off-board the vehicle systems. The time-variable risk profiles represent risks to travel of the vehicle systems that change with respect to time. An operator staffing demand for the vehicle systems may be determined based on the time-variable risk profiles. The staffing demand represents how many operators are needed for remotely controlling the vehicle systems at different times and a required qualification of one or more operators. The system and method also assign operators to remotely monitor and/or control the vehicle systems based on the risk profiles and, optionally, the staffing demand. The operator assigned to one or more vehicle systems changes with respect to time while the vehicle systems are moving along routes.
