In order to maximize the science return while minimizing running cost, the operational and maintenance requirements are being considered during the design of the GTC. Following this adopted integrated logistic support approach; GTC has produced the baselines of the GTC Operation and Maintenance Plans. These plans describe the science operation strategies, in particular those regarding the queue schedule mode, which will play the main role in the GTC operation scenario. Also the Operation and Maintenance Plans describe the maintenance activities and the support elements (staff, handling equipment, facilities...) that are being currently defined for the GTC future operational phase. This paper briefly summarizes the main items included in the Baselines of the GTC Operation and Maintenance Plans.