The use of complexity-based evaluation methods remains relatively underexplored in the field of evaluation. While increasingly employed to assess complex interventions, Contribution Analysis (CA) continues to suffer from a lack of operationalization. In this article, we propose enhancing the implementation of CA by leveraging Participatory Systems Mapping as a tool to delineate and scrutinize contribution narratives. The research has a dual objective. It aims to experiment with the recently introduced Participatory Systems Mapping method in the field of evaluation while providing a tool for examining contribution narratives. The combination of CA and Participatory Systems Mapping was tested by evaluating a youth employability project. This approach enabled a collaborative and in-depth examination of impact stories and alternative explanations. It proved valuable not only in managing the complexity of the intervention but also in strengthening the implementation of CA.