JET is the only operating platform within fusion where Remote Handling (RH) techniques have been developed to a stage that allows in-vessel maintenance work to be carried out fully remotely. JET's in-house team developed the methodology and a rational approach that allowed them to succeed in this task. This work clearly shows that the gap between developing the first prototypes and having an RH system ready for operational use, has a time and manpower costs which can easily be under-estimated. After a presentation of the context of this study this paper summarises some of the main lessons learned by JET RH team during the development and operation of their RH equipment. Starting from the JET example, the paper then tries to give ITER some references for the identification of areas of improvement and for evaluation of the amount of work and manpower costs that are really needed for a complete RH system to become fully operational and reliable.