An integral modelling approach for understanding the strengthening mechanisms in Ti alloys is presented and applied to alloys undergoing deformation via dislocation slip. The model incorporates contributions from solid solution, grain boundary, dislocation forest and strain hardening. The metal forming and thermomechanical processing factors influence both grain size and the stored strain energy. The strain hardening of Ti-Fe-Sn-Nb alloys was modelled by considering dislocation accumulation and annihilation terms. By tailoring the contribution of each strengthening effect, the yield stress and plasticity of advanced Ti alloys can be optimised.