Modelling of the long-term creep damage and lifetime is very challenging due to their strong stress level dependence. Aiming at developing a set of creep damage constitutive equations suitable for long-term service, research was carried out in modelling of the minimum creep strain rate, creep cavitation damage and rupture, and the coupling between creep cavitation damage and creep deformation. Firstly, based on the stress driven concept, the cavity nucleation model and cavity growth model were calibrated together using cavity histogram. Then, a simple analytical equation was derived to model creep cavitation damage. Furthermore, the creep cavitation damage model offered the theoretical background and supports for the stress-based extrapolation method and time-based extrapolation method. Two case studies were carried to explore the opportunities. This paper summarizes some of the progresses. This paper contributes to the generic methodology as well as the specific knowledge to the topic area.