Sequencing the evolution of technologies in a system-oriented way: The concept of technology-DNA

T-DNA is a new method for characterizing technological fields by means of patent classifications and analytical coding. In this method, technological fields are disaggregated into four system levels. Patent activities within technological fields are classified with respect to these system levels. A sequence of dominant system levels over the course of time emerges. As we see a strong analogy between this and the DNA-sequence of living organisms, we refer to this method as technology-DNA. Technology-DNA is applied in a case study in the logistics industry, in which we find that inventive activities focus on system components and associated systems.