This part contains the presentation and basic notions of the structural health monitoring methods, together with the introduction to the traditional and conventional monitoring techniques of composites. Textile fibrous sensors are characterized and their properties are presented. They are integrated to composite parts and issues related to this integration are addressed. Sensors are intensively characterized before and after their insertion to textile preforms. All the measurement results related to in situ monitoring are analyzed and discussed and the concept of predictive maintenance is introduced at the end of this part.