The early phase of product development is often described as particularly challenging. Especially in the case of innovations, various challenges that can be attributed to volatility, uncertainty, complexity and ambiguity (VUCA) are said to come into play. Far more often than breakthrough innovation projects, however, product development projects found in industrial practice incorporate incremental innovations on component or module level. This is especially the case for product developments within product families, where often a large part of modules and technical solutions are used in several products simultaneously and over several development cycles. The aim of this paper is to identify specific challenges especially in the context of the early phase of product families, to assign them to the four dimensions of VUCA and to put them in the context of different boundary conditions, such as novelty degree. For this purpose, a two-part approach was chosen: first, empirical studies concerning the early phase of the product (family) development are summarized, second, three explorative and semi-structured interviews were conducted. As a result, it can be concluded that challenges related to complexity, such as difficult decision-making in balancing internal and external goals or due to interdisciplinary cooperation and coordination between the partners involved, ambiguity, such as due to different interpretations of the same information, as well as uncertainty, such as not knowing about future customer requests, are of particular importance. Challenges related to volatility, on the other hand, were mentioned only sporadically. Furthermore, closeness to the customer, for example, seems to be a boundary condition that favours or prevents the occurrence of certain challenges in the early phase of product family development.