Facilitating an Event Storming Session

This guide will help you run effective Event Storming sessions at FlowMart, ensuring you get the most value from this collaborative modeling technique.

Pre-Session Preparation

1. Define the Scope

• Identify the business domain or process to explore
• Set clear objectives for the session
• Determine the appropriate level (Big Picture, Process, or Design)

2. Invite the Right People

• Domain experts who understand the business processes
• Technical team members who will implement the solution
• Product owners and stakeholders
• Limit to 8-12 participants for optimal interaction

3. Prepare the Space

• Large continuous wall space or virtual whiteboard
• Sticky notes in different colors:
  • Orange: Domain Events
  • Blue: Commands
  • Yellow: Aggregates
  • Purple: Policies
  • Pink: External Systems
  • Red: Problems/Questions

Running the Session

1. Introduction (15 minutes)

• Explain Event Storming concepts and notation
• Set ground rules:
  • No laptops/phones unless necessary
  • Everyone participates
  • No wrong answers
  • Focus on the business process

2. Event Discovery (45-60 minutes)

• Start with “What happens in this domain?”
• Let participants write domain events on orange stickies
• Place events on the timeline (left to right)
• Don’t worry about order initially

3. Timeline Organization (30 minutes)

• Review all events as a group
• Organize events chronologically
• Identify missing events
• Group related events together

4. Adding Detail (60-90 minutes)

• Add commands (blue) that trigger events
• Identify external systems (pink)
• Mark problem areas (red)
• Add policies and reactions (purple)

5. Identifying Boundaries (45 minutes)

• Group related concepts
• Look for natural service boundaries
• Discuss integration points
• Identify aggregates (yellow)

Common Challenges and Solutions

Challenge: Dominant Participants

• Actively engage quieter participants
• Use round-robin techniques
• Split into smaller groups temporarily

Challenge: Too Much Detail

• Keep focus on relevant abstraction level
• Park detailed discussions for later
• Use “parking lot” for important but off-topic items

Challenge: Losing Focus

• Take regular breaks (10 minutes every hour)
• Use timeboxing for each activity
• Keep referring back to session goals

Remote Facilitation Tips

When running remote Event Storming sessions:

• Use tools like Miro or Mural
• Pre-create templates and sticky note colors
• Use breakout rooms for small group discussions
• Schedule more frequent but shorter sessions
• Use video to maintain engagement

Post-Session Activities

1. Documentation

   • Photograph or export the board
   • Capture key insights and decisions
   • Document identified bounded contexts

2. Follow-up

   • Schedule deep-dive sessions for specific areas
   • Create action items and assign owners
   • Plan next steps for implementation

3. Review and Refine

   • Review findings with stakeholders
   • Validate assumptions
   • Plan additional sessions if needed

Measuring Success

A successful Event Storming session should:

• Create shared understanding
• Identify key domain events and processes
• Highlight potential problems and solutions
• Generate actionable next steps
• Engage all participants effectively

Next Steps

Continue to From Event Storming to Implementation to learn how to turn your Event Storming insights into working software.