In lightweight design, developers are used to face the conflicting objectives of functional fulfillment, economic performance, and sustainability. Against this background, however, a clearly structured approach for the satisfied use of specific lightweight engineering methods within the product development is still missing. Thus, this contribution deals with the fundamental conception and first implementation of a systematic development methodology covering the disciplines of mechanics, electrics/electronics and software just like the focus on an integrated view on product, production and material aspects. To ensure an application-specific manifestation of the product development process for three exemplary use cases from small and medium-sized enterprises but also large corporations in the area of prosthetics, bike construction and plant engineering, the individually developed methods and tools are first generalized in order to make them adaptable to a wide variety of industries. As a result, one lightweight-specific method or tool (e.g., function mass analysis, “PPM solution correlator“ or “2D layout & weight drafting”) is introduced in more detail for all stages of the technically extended RFL(T)P approach derived from model-based systems engineering (MBSE).