1. A method for operating a security system comprising the steps of: monitoring a protected area with a plurality of sensing elements, each of the sensing elements outputs a sensor signal; examining each sensor signal using at least one predefined evaluation criterion for each sensor signal and outputting a signature for each sensor signal; translating each signature into a normalized threat value using a scaling value; adjusting each normalized threat value using a preset weight coefficient that corresponds with the sensing element that output the sensor signal; storing for a temporary period of time, each adjusted normalized threat values; generating an aggregate threat value by adding each of the stored adjusted normalized threat values; and generating an alarm enable signal based upon analysis of the measured threat value.