This paper study the electric vehicle (EV) charging scheduling problem where EVs arrive at the charging station at unknown instants during the day with different charging demands and departure times. We consider the charging station designed such each EV has its own parking place. The objective is to built a real time schedule that minimize the total tardiness subject to the physical constraints of the charging station. To solve large instances, we propose heuristic based on the Priority Rule for Total Tardiness criterion. We consider preemptive as well as non-preemptive schedules. Simulation results indicate that the proposed heuristic outperforms the existing heuristics previously developed for the same problem.