Setup and Participants
How to prepare the room, the tools, and the right people for a productive Event Storming session
Learning Objectives
By the end of this module you will be able to:
- Identify the minimum physical and material requirements for an in-person Event Storming session.
- Evaluate the tradeoffs between physical and digital (remote) setups and choose appropriately for a given context.
- Define the participant composition needed for a productive session, including why both technical and domain experts must be present.
- Apply practical guidance for inviting and preparing participants before the workshop begins.
Core Concepts
The Room
Event Storming is a spatial practice. The physical or digital space you choose is not neutral—it actively shapes what your participants can think and say.
The core constraint to understand: Event Storming requires unlimited modeling space. If your participants sense a wall is running out, they will unconsciously start constraining their model to fit. That self-censorship is what you are trying to prevent.
Alberto Brandolini recommends an 8-meter wall as ideal, with a minimum usable surface of 1m × 10m. The room also needs to allow participants to walk alongside the timeline, step back to get perspective, and hold side conversations without disrupting the whole group. Larger rooms actively improve workshop outcomes.
A common mistake is setting up a room with a conference table and chairs. Event Storming works best standing up. People who sit down disengage. Move furniture out of the way before participants arrive.
The Modeling Surface
The traditional surface is long brown paper rolls (butcher paper) fixed directly to walls. This is deliberate. A plain paper surface encourages organic evolution of the model and accommodates spontaneous reorganization of sticky notes as understanding deepens. Pre-printed grids or bounded whiteboards impose structure before any thinking has happened.
Paper is also cheap, and cheap matters: it signals to participants that early-stage thinking is disposable and iterative, not precious.
The Markers
Provide black Sharpies (or equivalent permanent markers), one per person or more. This is not a minor detail. The marker has to be visible from several meters away—standard ballpoint pens and felt-tips are unreadable at distance. Permanent markers also prevent ink bleeding through layers of sticky notes on the paper surface.
The risk of under-supplying markers is real: participants wait for one to become free, the flow breaks, and the session loses momentum.
The Participants
The people in the room matter more than the tools in the room. A perfect setup with the wrong participants will produce a shallow model. The right participants in a cramped room will still surface valuable domain knowledge.
Effective Event Storming requires a heterogeneous group of participants with complementary expertise. The two essential poles are:
- Domain experts and business representatives — the people who know the answers. Product owners, subject matter experts, and business analysts who understand business rules, processes, and organizational boundaries.
- Software developers and technical staff — the people who ask the questions. Engineers who need technical clarity and who will eventually implement what the model describes.
A dedicated facilitator rounds out the core structure. Their job is to orchestrate the discussion, prevent the session from collapsing into side debates, and keep the timeline moving forward.
The optimal group size is 6–8 participants. The cross-functional composition is not optional: domain knowledge for complex systems is distributed across multiple individuals and departments—no single person fully understands the entire system. When domain experts and developers are in the same room, business rules, organizational boundaries, and technical constraints all surface through dialogue. Bringing them together later, as a separate documentation step, consistently produces shallower results.
What happens at the extremes:
- Fewer than 4 participants means insufficient perspective coverage. You will produce a model that reflects one team's partial view of the domain, not the domain itself.
- More than 10 participants becomes difficult to facilitate and tends to silence quieter contributors. If you have more people than this, consider splitting into parallel streams or running multiple focused sessions.
Compare & Contrast
In-Person vs. Digital Event Storming
The choice between physical and digital is not simply a matter of convenience. Each format makes different things easy and different things hard.
| Dimension | In-Person (Physical) | Digital (Remote) |
|---|---|---|
| Collaboration texture | Spontaneous, spatial, embodied | Structured, explicit, tool-mediated |
| Setup cost | Low (paper, markers, sticky notes) | Medium (tool setup, templates, training) |
| Facilitation demand | Moderate | High |
| Artifact persistence | Poor (photos of sticky notes) | Strong (persistent digital boards) |
| Remote access | None | Full |
| Productive friction | Natural (physical space creates focus) | Reduced (infinite canvas removes constraints) |
Physical workshops excel at knowledge emergence. The constraints of limited wall space and physical proximity create natural focus. Physical sticky notes remain prevalent in design processes due to their tangibility—they are easy to move, cheap to discard, and create a shared spatial model everyone can point to simultaneously.
Digital workshops make geographic access and persistence easy. Tools like Miro and Mural provide infinite canvas space, virtual sticky notes, and real-time collaboration. Asynchronous contributions become possible, and the resulting model can be directly versioned or integrated with downstream tooling like Context Mapper, which can generate UML diagrams or service contracts from captured Event Storming results.
The infinite canvas of digital whiteboards can paradoxically reduce workshop effectiveness. When there is no physical constraint on space, participants feel less pressure to make hard choices about what belongs on the board. The productive friction of a real wall—with real limits—is part of what makes in-person sessions effective.
The honest tradeoff: Neither format inherently solves the maintenance challenge; both require organizational practices to sustain model value over time. The question to ask is not "which is better?" but "which fits our current constraints?"
When to choose physical: Your team is co-located, you are running a Big Picture session with strategic stakes, or this is the group's first Event Storming session.
When to choose digital: Your participants are geographically distributed, there is a clear need to preserve and reuse artifacts downstream, or key domain experts cannot commit to a full-day in-person session.
Key Principles
1. Space is an argument. Providing an 8-meter wall communicates that the scope of this exploration is unlimited. Providing a small whiteboard communicates the opposite. The physical space you choose sets expectations before a single sticky note goes up.
2. Marker quality is a proxy for preparation quality. Showing up with fine-point pens signals that you did not think through the practicalities. It also breaks the workshop flow every time someone cannot read a sticky note. Prepare more markers than you think you need.
3. Heterogeneous participants are not optional. The fundamental mechanism of Event Storming is dialogue between people who know different things. A room full of developers will produce a developer's mental model of the domain. A room full of domain experts will produce a business narrative without technical grounding. You need both.
4. Facilitating remote sessions costs more. Remote Event Storming requires more preparation, structured guidance, and facilitation intensity than in-person sessions. Budget for a two-facilitator model when working remotely: one manages the storytelling and timeline; the other tracks emerging hotspots and comments in the tool. If you cannot staff two facilitators, lower the scope of the remote session accordingly.
5. Domain knowledge is distributed. No single person fully understands a complex system. This is the core justification for assembling a cross-functional group. Your goal is to surface distributed knowledge, not to validate what one expert already knows.
Active Exercise
Participant Roster Review
Before your next Event Storming session, build a participant roster using the following structure. This exercise forces you to make participation decisions explicit before the workshop day.
Step 1: List your invited participants. For each person, note their role and their primary knowledge domain.
Step 2: Categorize each participant. Assign each person to one of these three categories:
- Domain expert / answers-holder (knows business "why")
- Technical contributor / questions-asker (knows implementation "how")
- Facilitator
Step 3: Apply the coverage tests.
| Test | Your answer |
|---|---|
| Do you have at least one domain expert per major business subdomain being explored? | |
| Do you have developers or architects who will implement what the model describes? | |
| Do you have a dedicated facilitator who is not also a domain expert or developer? | |
| Is your total group between 6 and 10 participants? |
Step 4: Identify and fix gaps. If you answered "no" to any test above, identify who is missing and what it would take to include them. If adding the right person pushes the group above 10, consider whether the session scope should be narrowed.
Decision point: If you cannot assemble a cross-functional group (domain experts + technical contributors), do not run the session. Reschedule until the right people can participate. A homogeneous group will produce a partial model and create false confidence.
Key Takeaways
- Physical space is a design choice. An 8-meter wall is the target; anything below that forces participants to self-constrain. Remove furniture and chairs before the session begins.
- The modeling surface and markers are load-bearing materials. Brown paper rolls and black permanent markers enable the visibility and spatial flexibility the method depends on. Substitutes consistently degrade the experience.
- 6-8 participants with mixed roles is the effective range. Below 4 and you lack perspective diversity. Above 10 and facilitation breaks down. The composition -- domain experts plus technical contributors plus a facilitator -- is not negotiable.
- Digital setups unlock remote participation but increase facilitation cost. Remote sessions require pre-prepared boards, mandatory video, tool training, and ideally two facilitators. They also enable artifact persistence and downstream formalization in ways physical sessions cannot match.
- Distributed domain knowledge is the problem Event Storming is solving. Your participant list is your primary instrument. Get it right before you worry about anything else.
Further Exploration
- How to prepare the room for a Big Picture Event Storming — Event Storming Journal — Detailed physical room setup guidance, including wall preparation and sticky note logistics.
- Remote Event Storming: Your Step-by-Step Preparation Guide — Event Storming Journal — A thorough treatment of the additional preparation required for virtual sessions.
- Why Go Remote with Event Storming? Surprising Benefits — Event Storming Journal — The case for remote sessions; useful counterbalance to in-person bias.
- Remote Event Storming Challenges — SoftwareMill — A practitioner's account of what goes wrong remotely and how to address it.
- Context Mapper — Event Storming Documentation — How to formalize Event Storming artifacts into machine-readable domain models for downstream processing.
- Collaborative Process Modelling with EventStorming — Alberto Brandolini — The originator's perspective on the methodology and its underlying mechanics.
- Physical Versus Digital Sticky Notes in Collaborative Ideation — Springer — Academic research on the tradeoffs between physical and digital collaborative artifacts.