Hi Daniele,
Inherent Risk: risk situation before any actions has been put in place nor executed.
Residual Risk: corresponds to today's risk situation
Residual Risk Planned: corresponds to where you will arrive when responses
will be effective & 100% complete.
Mitigation actions will only have impact over residual risk if the linked response's effectiveness is partially or completely effective and completeness % is more than 0%.
Kind regards,
Pascal