The optimum conditions for access to and sustainment of H-mode plasmas and their expected plasma parameters in the Pre-Fusion Power Operation 1 (PFPO-1) phase of the ITER Research Plan, where the additional plasma heating will be provided by 20 MW of Electron Cyclotron Heating (ECH), are assessed in order to identify key open R&D issues. The assessment is performed on the basis of empirical and physics-based scalings derived from present experiments and integrated modelling of these plasmas including a range of first-principle transport models for the core plasma. The predictions of the integrated modelling of ITER H-mode plasmas are compared with ITER-relevant experiments carried out at JET (low-collisionality high-current H modes) and ASDEX Upgrade (significant electron heating) for both global H-mode properties and scale lengths of density and temperature profiles finding reasonable agreement. Specific integration issues of the PFPO-1 H-mode plasma scenarios are discussed taking into account the impact of the specificities of the ITER tokamak design (level of ripple, etc.).