Capillary self-assembly is rapidly emerging as an innovative technique to enhance, complement and eventually replace pick-and-place assembly for the integration of heterogeneous microsystems. Vast literature and experimental data support such claim. Yet, the technique needs to overcome important limitations in order to earn wide industrial recognition. In this talk, we illustrate the challenges ahead for making part-to-substrate capillary self-assembly reliable and seriously competitive. We focus on the standard embodiment of capillary self-assembly, and we describe in details the often novel technological steps required for its effective and reproducible performance. This preludes to an outline of what are presently the major failure modes affecting the overall yield of the technique. Consequently, we propose solutions to face these challenges and foster the success of this technique.