Journey to Rome is an easy-to-use risk assessment methodology for new demands or change requests of software, as well as existing functionality.
When testing software we have to face a harsh reality: Due to various constraints (time, budget, people), it is unfeasible to attain 100% test coverage. In other words, it's impossible to test everything. Risk-based testing prioritizes testing of features and functions of the software application where defects are more likely and have a higher impact.
There are various ways to assess risk, each coming with their own tradeoffs. Some of them are too simplistic (e.g. a single value, ranging from Low to High) and based on gut feeling rather than objective criteria, making it hard to explain how the value was chosen. Some of the methods are elaborate and time-consuming, often involving multiple stakeholders (business analyst, vendor, project management, demand management, ...). Most of them are geared towards project risk.
Journey to Rome hits the sweet spot. Basically, you ask a series of questions which can be answered by the requestor of a demand or user of a feature. It is not necessary to involve the vendor/developer of the software.