Event Storming is a powerful technique that allows one to uncover and visualize processes within a system. The Event Storming sessions are run in a workshop format, where domain experts and developers collaborate to produce a visual representation of the events that happen in the system, data flow, actions and any side effects. The result of such a workshop is a whiteboard (or a digital board) with a lot of sticky notes, providing a birds-eye view of the process flow.
The sessions aim to not only get the answers but to also find the correct questions. During the discussion inconsistencies in the knowledge across teams are uncovered. Event Storming also helps to define a ubiquitous (common) language that is to be used, reducing the probability of communication issues. Perhaps the strongest advantage of an Event Storming session is that no prior experience is required, there are very few basic rules to follow and the rest is just a discussion. Our blog post about Event Storming goes into more details and also provides some ideas and use cases.
We have successfully run event-storming sessions with our clients to uncover system requirements on numerous occasions. We also developed our own carefully crafted Miro board with tips and reminders for the participants, so that it is even easier to introduce them to the workshop rules. In practice, some of such sessions gave us more insight in four days than we could have been gained by spending the same time going through the documentation.