A method, system and apparatus of optimizing operation of one or more tubing strings in a hydrocarbon well are provided. Each tubing string is located in a hydrocarbon well and has a plurality of valves. Each valve is actuatable between a fully open position and a fully closed position and is in communication with a respective zone of a formation defining a reservoir containing hydrocarbon material. The method includes characterizing an injectivity of one or more zones of the formation and determining an optimal operating schedule in accordance with the characterization. The optimal operating schedule comprises one or more valve configurations and an operating duration for each of the one or more valve configurations.