A medical method includes: determining a first probability density function related to a first uncertainty in hitting a target in a treatment of the target determining a second probability density function related to a second uncertainty, wherein the first uncertainty is attributable to a first source of uncertainty, and the second uncertainty is attributable to a second source of uncertainty that is different from the first source of uncertainty processing at least the first probability density function and the second probability density function using a processing unit and outputting a result of the processing.
