This article describes the action-research process carried out to redefine and design a program for children and adolescents with difficulties and/or conflictive situations in the family. The design of the NAYFA program has been carried out following the quality standards of evidence-based programs and through a collaborative process between policymakers, professionals and researchers. The SWOT technique was used to identify the main strengths and weak-nesses of the previous actions carried out in different Andalucía provinces. The results revealed an important lack of ystematization that an attempt has been made to solve by defining, through a collaborative process and in accordance with the most agreed quality criteria, the key components of the new program: theoretical and methodological founda-tions, recipients, objectives, contents, implementation conditions and evaluation design. The high degree of agreement of professionals and managers with the proposed characteristics can contribute to the implementation of the program being carried out with fidelity to the original design and, thus, favor its effectiveness.