Communities of Practice have been receiving significant attention in companies for some time now. They are attributed a key role, particularly in promoting work-integrated learning processes and in disseminating organization-relevant knowledge. However, as a downside to this growing importance, their actual learning potential remains largely unclear. This work takes this as an opportunity to establish an analytical approach that models Communities of Practice as informal learning networks and makes the potential contributions of these learning networks to individual and organizational competence development transparent. Building on this, it is explained how informal learning networks can be strengthened in their learning effectiveness through corporate training using a network didactics approach.