A scenario parameter optimization method performed by processing circuitry, the method comprising:
- receiving an execution result of a simulation test of a scenario including a first agent and a second agent, executed on a basis of a scenario parameter, and calculating an object function value of a predetermined event from an object function expressing the predetermined event, and an event occurrence time at which the predetermined event occurs on a basis of the execution result;
- determining whether or not the first agent is responsible for the occurrence of the predetermined event from a situation at a responsibility determination time before the calculated event occurrence time on a basis of the execution result and the calculated event occurrence time, and outputting a result of the determination as a responsibility determination result;
- and
- optimizing the scenario parameter in such a manner that the calculated object function value decreases and the first agent is determined to be responsible for the occurrence of the predetermined event on a basis of the calculated object function value and the output responsibility determination result.