Path to the $0.01%$ Theoretical Luminosity Precision Requirement for the FCC-ee (and ILC)

We present pathways to the required theoretical precision for the luminosity targeted by the FCC-ee precision studies. We put the discussion in context by reviewing briefly the situation at the time of LEP. We then present the current status and routes to the desired 0.01% targeted by the FCC-ee (as well as by the ILC).