The establishment of reliable correlations between the extend of damage and a sensor response using automated non destructive testing (structural health monitoring) is the first aim of the present paper. The second and its main aim is the estimation of the efficiency of different approaches of the fatigue crack prediction when scalar parameters are used to represent the signal-response. Investigation of ultrasonic Lamb wave interaction with a fatigue crack has been performed on thin sheets (1mm) of aluminum alloy (2024-Т3). Three parameters of response were selected to compare efficiency and the standard deviation of a predicted fatigue crack was used for comparison. Quite definitely it is possible to conclude, that the proposed technology is capable of providing high stability and necessary accuracy at the continuous integrated SHM of thin-walled aluminum components of aircraft. It is also shown that the accuracy of damage prediction is one of the most significant parameter of SHM efficiency. It can be used as the main criterion at selection of diagnostic parameters for continuous integrated monitoring of structural elements of aircraft.