Disruptive innovations, as opposed to sustaining innovations, bring change to customers, markets, industries. This change is often quite sudden and drastic. Thus, the early identification of disruptive technologies can be crucial for managers and policy makers alike. In this work we propose a method to support the early identification of disruptive innovations. To do so we conceptualize a 5-phase pathway framework for disruptive innovation, then propose how to operationalize its phases using patent data. We combined the underlying theory by Christensen with different patent indicators from literature to develop an early warning system for disruptive innovations based on the underlying disruptive technologies. Additionally, we introduce the concept of patent zero and provide a first analysis.