This work package is dedicated to the development of optimal performance assessments on the various stages of the project and for the other WPs. Performance functions will evolve through the project and become more detailed, starting from the physical-engineering problem of the maximisation of wave energy absorption and convergence of the wave power to the shaft power, and ending with the optimisation of Levelised Cost of Energy (LCoE). The work package will derive a set of particular performance sub-functions for specific control assessments using results from the CycWEC and LiftWEC projects. As a starting point we will use the open access deliverables and methodology from the LCoE work package of the LiftWEC project. Some of these functions will be used to define the current goal for each of the tasks of technical WP2-WP3 in terms of mechanical or electrical power maximisation, and other special performance functions will be used to assess MaxRotorWEC in terms of financial viability and show its benefits. At the final stage of the project, these subfunctions will be merged into one function which will allow us to evaluate the MaxRotor-WEC farms’ performance in terms of LCoE.