The ongoing digital transformation and internationalization of business processes cause a shift towards a more collaborative nature of processes. In such collaborations, different organizations execute separate parts of the process autonomously. This fragmentation leads to uncertainty regarding the correct execution of activities, the proper workflow, and data in the process flow. If organizations engage in business together, trust is needed. Therefore, we propose Trust Mining as an analytical approach to better understand uncertainties and the potential trust issues that arise from them. Trust Mining takes a business process model as an input and analyzes uncertainties and relationships. In the end, an evaluation regarding the trust requirements of specific stakeholders is given. Furthermore, we present a prototypical implementation and illustrate how Trust Mining can be used in trust-aware process (re-)design.