Functions in the Early Phase of Product Development: A Systematic Literature Review

Functions deserve special attention in the design and differentiation of products in the early phases of product development. However, it has become apparent that there is no uniform understanding of a function. This contribution analyzes and deepens the understanding, formulation and modeling of functions in research and product development in the early phases of development with the approach of a Systematic Literature Review (SLR). In literature, a function is primarily described from the (established) developmental perspective, but rarely from an environmental or human-centered viewpoint. In the latter case, such a function understanding enables the specification of a customer and user-oriented system of objectives. Furthermore, a purposeful formulation of a function can create a mutual comprehension among product developers and increase transparency in the early phase of research and development. There is a consensus to formulate a function as a noun-verb combination. In addition, the literature study has led to the conclusion that the level of abstraction should be taken into account when formulating a function. The results show the need of further research on defining a function on different product levels (system-of-system in the environment, subsystem and component) as a coherence of an initiating event and the desired outcome.