Event Storming Cheat Sheet: Big Picture Exploration

Event Storming (Big Picture Exploration) is rapid domain modeling using color-coded sticky notes. It is not meant to be strict, and requires some fuzziness. The goal is to collaboratively find hot spots.

Event Storming is run as a facilitated workshop. Get the right people (a good mix of business and technical) into the room. Provide a large modeling space and plan for a two-hour timeframe.

The modeling space is a timeline. Start with the events that are relevant to the business. Get everybody engaged. Some guessing is legitimate. Phase 2 is a walk-through from beginning to end to enforce the timeline by ordering the events. In phase 3, reverse the narrative by going from the end to the beginning to find gaps and inconsistencies. In phase 4, identify actors (users and external systems). In phase 5, choose hot spots to focus on, and explore them in greater depth.

The model visualizes the current understanding. It will change over time.

Event Storming supplies at https://eventnotes.io.In-depth information about Event Storming at http://eventstorming.com.You can also get Alberto‘s book there, which is a very recommended read.

Aggregate (yellow) – processes commands and emits Domain Events (DDD pattern)

Command (blue) – a request to do something

Domain Event (orange) – something that happened, past tense + verb (Event Sourcing/CQRS pattern)

External System (purple) – just what you would expect

Policy (pink) – algorithm or decision, manual or automated (Strategy Pattern)

Read Model (green) – data needed to make a decision (CQRS concept)

User (small yellow) – actor, user, persona, or role

User Interface (white) – just what you would expect