The increasing digitalisation of society entails not only extensive dependence on technical systems, but also a dependence on satellite services that allows for these technical systems to function. The time and frequency services provided by Global Navigation Satellite Systems (GNSS) are examples of such satellite services. This means that interference with GNSS can cause disruptions in technical systems, which in turn affect actors and their abilities to carry out tasks. This report contains methodological support for actors conducting vulnerability analyses, including the risk and vulnerability analyses (RVAs) that government agencies, regions, and municipalities are required to carry out under current legislation. The method support is intended to aid in identifying how an actor's operations may be affected when GNSS time and frequency services are jammed or spoofed. The report outlines a seven-step workflow for analysing GNSS dependences. It also includes examples of relevant dependencies. The seven steps are: i) staffing the analysis group, ii) mapping prioritised commitments, iii) identifying critical dependencies on technical systems, iv) identifying the technical systems' dependencies on time and frequency via GNSS, v) mapping system redundancies, vi) examining how prioritised commitments are affected by jamming or spoofing, vii) ensuring internal and external knowledge transfer through RVA reporting.