Techniques are disclosed for generating a hitless migration plan to optimal state, given an optimal routing and wavelength assignment for demands. For example, a technique for use in performing a circuit transition in accordance with an optical ring-based network comprises the following steps/operations. First, a first (e.g., initial) circuit layout and a second (e.g., final) circuit layout for a given set of demands to be routed on the optical ring-based network are obtained. Then, a minimum number of free wavelengths required to transition the network from the first circuit layout to the second circuit layout is determined such that substantially no network service disruption occurs due to the circuit transition.