Function management system and function management method

A function management method performed by a computer of a function management system which manages utilization of option functions in a vehicle, the method comprising:

• an information collection step of collecting failure information including information about a failure of an electronic controller loaded in the vehicle and/or information about a failure of an instrument controlled by the electronic controller;
• and
• a determination step of determining whether or not execution preparation for utilization start is possible for each of the option functions,
• wherein, in the determination step, the execution preparation of the option function is determined to be impossible when a failure has been found in the electronic controller or the instrument required for execution of the option function, for each of the option functions, based on the failure information.