Two novel dynamical quality of transmission (QoT) optimization schemes with explicit optimization targets and accurate end-to-end QoT estimation are proposed for reconfigurable transparent wavelength-division multiplexing (WDM) networks. Numerical simulations show that the scheme of quality (Q) best has the best Q factor improvement with large attenuation adjustment. The scheme of Q allowable can achieve minimized number of tuning sites and attenuation adjustment and also improve the Q factor of light path to the required value. In addition, the idea of dynamic QoT optimization and global impairment control has been experimentally demonstrated on a simple mesh network by the cooperation of a control plane and tunable devices.