This paper discusses new conceptual and mathematical models for blistering propagation especially useful for coating life assessment. It proposes new equations governing blister development that combines fracture mechanics and diffusion based concepts. The fracture mechanics concept is used to treat blister growth as crack propagation, while the diffusion concept is used to treat the ionic transport that eventually causes corrosion and blistering to occur. The new equations are expected to be useful in coating development as well as coating life assessment. Furthermore, with little modification, the equations are also beneficial for other surface engineering methods.