In the framework of the problem the following issues were considered: control reliability and flaw detectability, defect rating, points, volume and parameters of the control, periodicity (time intervals between inspections), using of test blocks for control equipment and personnel qualification, control arrangement under various processes of structure metal damages including control of the defects due to the technology factors, fatigue cracks, flaws due to corrosion cracking.

The description of the techniques of in in-service inspection optimisation to achieve the maximum control efficiency under the given technical and economic conditions or to achieve the defined level of reliability of the structure being under control is given. The specific examples are shown to demonstrate the practical realisation of a number of the key theoretical, methodical and technological approaches.