Further development and applications of the analytical model, presented in Part 1 and Part 2, are presented in this paper. These involve extension of the analysis for bi-material systems to multi-layered cases and determination of the critical strain energy release rate from a knowledge of the point at which debonding occurs. Mention is also made of the possibility that, since relaxation of stresses parallel to the crack front cannot occur close to the crack tip, the associated strain energy may not contribute fully to the effective strain energy release rate. An outline is given of how the model can be used in conjunction with experimental data on specimen curvature to determine the deposition stress of the coating. Some suggestions are also made about how predicted residual stress distributions could be validated, using X-ray diffraction or layer removal techniques.