The Cherenkov Telescope Array (CTA) is the next generation ground-based γ-ray observatory. We make use of the Fermi-LAT 3FHL catalogue and the software package Ctools to discuss a detailed analysis of the extragalactic source population (mostly blazars) that will be studied in the near future by CTA. This analysis is based on simulations built from the expected array configurations and information reported in the 3FHL catalogue. We also touch upon the standard analysis chains in Ctools as well as take into account the extragalactic background light.