A company runs an Event Storming workshop with 25 people from 6 departments on a single wall. Two hours in, the group has covered the wall in sticky notes but produced no shared understanding, with sub-groups working on disconnected parts of the timeline. What went wrong, and what facilitation practices prevent this?

## A facilitation gap, not a technique gap A wall full of sticky notes with no shared understanding is the single most common Event Storming failure story, and it almost always traces to a facilitation gap rather than to the technique itself being unsuitable for large groups — large, diverse groups are exactly where Event Storming should shine, but only with active management. ## What actually goes wrong Mechanically, what goes wrong is predictable: put 25 people from 6 departments in a room, hand them stickies, and tell them to write domain events, and left unmanaged, people gravitate toward the colleagues they already know. - A sales cluster writes a sales-flavored version of the process. - A warehouse cluster writes a warehouse-flavored version a few feet away. - A support cluster does the same. Each sub-group produces a locally coherent, internally consistent sub-timeline — which is why the wall looks "full" and productive from a distance — but the sub-timelines were never forced to confront each other, so the exact friction the whole technique is designed to surface never happens. The session ends with more sticky notes than anyone can read, but not more shared understanding than existed at 9am, because the room quietly self-organized back into the same silos that caused the knowledge gap in the first place. ## What active facilitation actually does The reason active facilitation exists as a distinct, deliberate role — not just "someone hands out stickies and starts a timer" — is that a roomful of busy professionals defaults to whatever's socially easiest, which is staying with people they already know and avoiding confrontation over conflicting terminology. Good facilitation counters this specifically. 1. A facilitator, sometimes with a co-facilitator for a group this size, **actively roams the wall** watching for duplicate or near-duplicate events written by different sub-groups, and pulls the relevant people together right there to reconcile them on the spot, rather than letting both notes coexist unresolved. 2. **Periodically** — every 20-30 minutes for a large group — the facilitator calls a full stop and has someone, rotating who so it isn't always the same dominant voice, read the timeline aloud from one end to the other while the whole room listens, explicitly asking "does this match what your part of the business does?" This narrated walk-through is the mechanism that actually forces sub-groups to notice when their local model contradicts a neighboring one. ## The trade-off The trade-off of doing this well is **time and facilitator skill**: proper turn management, merge conflicts, and full-timeline walk-throughs for a 25-person, 6-department group easily consume the entire session length just on reconciliation, leaving less wall-clock time for raw event generation than a naive read of "we have 4 hours, so we'll spend 3.5 writing stickies" would assume. Teams that under-budget facilitation time in favor of maximizing raw sticky-note output get exactly the fragmented, unreconciled-wall outcome described here. The upside of budgeting it correctly is that the reconciliation, done live in the room with the right people present, is dramatically cheaper than discovering the same department-level disagreement six weeks later mid-implementation, when it surfaces as a production incident instead of a five-minute sticky-note discussion. ## How the failure shows up In practice this failure mode shows up as: - two "Order Cancelled" events on opposite sides of the wall that nobody merged; - sales and warehouse teams both confidently pointing at different notes when asked "what happens after Payment Authorized"; - or — most telling — a facilitator asking the full room at the end "does everyone agree this is how it works?" and getting silence rather than genuine assent, because most people never actually looked at more than their own corner of the wall. ## The same session, run two ways Concretely, at a mid-size retailer running exactly this kind of large, cross-departmental session: | Session | Outcome | |---|---| | A facilitator who scheduled mandatory checkpoints every 30 minutes — stopping all sub-groups, having one department read their section aloud, and asking the room to physically point at and challenge any note they disagreed with | caught a sales/warehouse conflict over what "Order Cancelled" meant within the first checkpoint, resolving it in under ten minutes | | A comparable session without scheduled checkpoints, run at another site by the same company | produced exactly the fragmented, disconnected-wall outcome the question describes, and the conflict surfaced weeks later as a mis-shipped, already-cancelled order |