Abstract: Techniques for validating operation of a perception system that is configured to detect objects in an environment of a vehicle are described herein. The techniques may include receiving log data representing a real scenario in which the vehicle was traversing an environment. Based at least in part on the log data, an error may be identified that is associated with an output received from the perception system while the vehicle was traversing the environment. In some examples, a determination may be made that a magnitude of the error violates a perception system requirement, the requirement established based on a determination that the magnitude of the error would contribute to an adverse event in an alternative scenario. Based on the magnitude of the error contributing to the adverse event, data associated with the error may be output for use in updating the perception system to at least meet the requirement.