A system for generating a radiotherapy treatment plan for a patient, the system being configured to optimize treatment parameters on the basis of treatment goals comprising optimization objectives and/or constraints including requirements for a radiation dose to be delivered to at least one body region of the patient, and the system comprising: a planning unit configured to generate a first treatment plan including treatment parameters for fulfilling first treatment goals in a first optimization cycle, and a decision unit configured to - receive second treatment goals and to compare the first and second treatment goals to determine a modification of the second treatment goals relative to the first treatment goals; - assign to the modification a category from a plurality of predetermined categories of modifications, wherein to each category a strategy from a plurality of predetermined strategies for treatment plan generation is allocated, - determine the strategy allocated to the category assigned to the modification and to instruct the planning unit to generate the second treatment plan in accordance with the determined strategy in a second optimization cycle, characterised in that : at least one category of modifications includes modifications comprising an addition of at least one objective to the first treatment goals and wherein the strategy allocated said category comprises a decomposition of the calculation of the second treatment plan into successive partial calculations, one partial calculation corresponding to the calculation of the first treatment plan and a further partial calculation corresponding to an optimization on the basis of the added objective. a planning unit configured to generate a first treatment plan including treatment parameters for fulfilling first treatment goals in a first optimization cycle, and a decision unit configured to - receive second treatment goals and to compare the first and second treatment goals to determine a modification of the second treatment goals relative to the first treatment goals; - assign to the modification a category from a plurality of predetermined categories of modifications, wherein to each category a strategy from a plurality of predetermined strategies for treatment plan generation is allocated, - determine the strategy allocated to the category assigned to the modification and to instruct the planning unit to generate the second treatment plan in accordance with the determined strategy in a second optimization cycle, - receive second treatment goals and to compare the first and second treatment goals to determine a modification of the second treatment goals relative to the first treatment goals; - assign to the modification a category from a plurality of predetermined categories of modifications, wherein to each category a strategy from a plurality of predetermined strategies for treatment plan generation is allocated, - determine the strategy allocated to the category assigned to the modification and to instruct the planning unit to generate the second treatment plan in accordance with the determined strategy in a second optimization cycle, characterised in that : at least one category of modifications includes modifications comprising an addition of at least one objective to the first treatment goals and wherein the strategy allocated said category comprises a decomposition of the calculation of the second treatment plan into successive partial calculations, one partial calculation corresponding to the calculation of the first treatment plan and a further partial calculation corresponding to an optimization on the basis of the added objective. <EOS>