This paper examines the impact of the International Labour Office’s (ILO) concept of Decent Work on development thinking and the associated literature. We attempt to answer the question of what makes a development initiative successful by comparing the decent work approach to the United Nation Development Program's (UNDP) human development concept (in conjunction with the human development indicator). We consider that the latter has been one of the most successful development concepts ever to have been launched, while the impact of decent work by comparison has been limited. Our hypothesis relating to the question of what makes a development initiative successful has three fundamental components: first, a solid theoretical foundation has to justify the launch of a development concept. A second vital factor is the availability of sufficient national and internationally comparable data that enables researchers and policymakers alike to apply the concept, preferably by means of a synthetic indicator. Third, the political will and institutional structure of the development institution that launches a concept is a key factor, particularly if data availability is limited as countries then have to be persuaded to generate new data.