Raising the employment rate is a key ambition in Belgium and other OECD countries. A recent objective in this respect is to activate inactive persons, i.e. those who are neither working nor looking for work. In contrast to what is the case concerning unemployed, who do look for work, scientific knowledge about the barriers that prevent the employment of inactive persons is very limited, so that policies cannot be developed in an evidence-informed manner. Within the framework of this project, we want to study these barriers in depth. This implies that we combine the research tradition from labour economics on barriers on the employee and employer side and the research tradition from data science on matching both sides through artificial intelligence. From an integrated insight into these thresholds, we then develop solution-oriented work packages in which interventions are scientifically designed and evaluated.