[en] In the present paper, the aspects of optimizing In-Service Inspection (ISI) is discussed. Slovenian Nuclear Safety Administration (SNSA) and its authorized organization for the ISI activities, Institute of Metals and Technologies, are permanently involved in the ISI process of the nuclear power plant (NPP) Krsko. Based on this experience and additionally gathered by reviewing of the new ISI program, the decision was made to improve recent regulatory and professional practice. Traditional criteria, standards and practice are bases for the further improvements. Improvements will be done by adding a new knowledge about the safety important components of the systems to the basic practice. It is necessary to identify conditions of the safety important components, such as realistic stress and fatigue conditions, material properties changes due aging processes, the temperature cycling effects, existing flaws characterization in the light of the previous detection and equipment technique used, assessment of the measurement accuracy on the results etc. In addition to the above mentioned, risk assessment and evaluation of the whole ISI shall be done. To do this it is necessary to make risk evaluation, based on previous structural element probability assessment. Probabilistic risk assessment is important and one of the most powerful tools in the ISI optimization. Some basic work in the field of the risk informed methods related to the nuclear safety components has been already done. Based on reference documentation, the most important steps in risk informed ISI are discussed. Those steps are scope definition, consequence evaluation, failure probability estimation, risk evaluation, nondestructive examination method selection and possibilities of implementation, monitoring and feedback. Recent experience on the ISI in the nuclear world show that such practice is very important during ISI decision making process and has some measurable effects too. It is clear that classical criteria for the selection of ISI inspection locations are not completely in accordance with current measures of nuclear safety. ISI optimization shall give benefits to the operator of nuclear facility (on the resources and duration of the ISI inspections) and to the SNSA (more effective control of the safety important components, aging management control and overall nuclear safety).(author)