Today we map how our business works as a story of events, written on sticky notes along a paper roll. You don't need to prepare anything or know a modelling technique. We need what you know about the work.
Sticky note colours
Order Placed
Domain eventOrange. Something that happened and matters to the business, written in the past tense. Most of what you write today will be events.
Big PictureProcessDesign
Who pays return?
HotspotNeon pink, at a slight angle. A question, conflict, pain point or open issue.
Big PictureProcessDesign
Customer
ActorSmall yellow. A role, team or department involved in an event.
Big PictureProcessDesign
Payment Gateway
SystemWide pink. A tool or organisation we depend on, such as Excel, an internal app or an external partner.
Big PictureProcessDesign
Self-service returns
OpportunityGreen. An idea for an improvement, the positive counterpart to a hotspot.
Big Picture
+ −
ValueSmall green or red. Where we gain value or money (green) or lose it (red).
Big Picture
Whenever paid, ship
PolicyLilac. A reaction: "whenever X happens, we do Y". A person or a system can carry it out.
ProcessDesign
Place Order
CommandBlue. A decision or action that causes an event, written as an instruction: Place Order.
ProcessDesign
Cart Summary
InformationGreen. What someone looks at to make a decision. Also called a read model.
ProcessDesign
Order Rules
ConstraintLarge yellow. The business rules that decide whether an action is allowed.
Design
Checkout screen
User interfaceWhite. A rough sketch of a screen or form where someone sees or enters data.
Design
→
TimelinePaper roll and tape. Time runs from left to right. Vertical lines mark pivotal events, horizontal tape makes swimlanes.
Big PictureProcessDesign
You don't need to memorise these. The facilitator adds a colour to the legend on the wall when we start using it, and most sessions begin with orange only. The tags show which type of EventStorming uses each colour.
Ground rules
There are no chairs, on purpose. Stay at the wall, and keep laptops and phones away.
Everyone gets a marker and writes their own stickies.
During the silent phase, write and don't talk. Discussion comes next.
Duplicates and mistakes are fine. We clean them up together.
If you disagree with something, put a hotspot on it instead of arguing it out.
You can move anyone's sticky. Ask before removing one, because the same word can mean different things to different people.
Ask about every term you don't know. Others probably don't know it either.
Everyone's sticky counts the same. The people who do the work often know the most.
Writing a domain event
Write one event per orange sticky, with the verb in the past tense.
Use a marker and write large enough to read from 2 m away.
Use the words people use at work, and avoid technical jargon.
Leave out who did it. People go on yellow stickies.
If you're unsure about an event, write it anyway. Others will correct it.
✓Order PlacedInvoice SentParcel Returned✗Ordera noun; nothing happened✗Place orderan intention; use the past tense✗Customer placed orderleave out the actor✗Row saved in DBa technical detail
Where to start writing
Try something you worked on last week, what arrives on your desk and what you hand on, the last step before the customer pays, or something that often goes wrong.
Today's agenda
This is a typical Big Picture session. Your facilitator may skip or reorder steps.
Check-in. A short round: how are you, and what do you want to get out of today?
Chaotic exploration. Write every event you can think of, without talking, and stick each one roughly where it happens in time. Read what others put up.
Enforce the timeline. Now everyone talks. Sort the events into one story, merge duplicates that really mean the same thing, and mark conflicts with hotspots.
Find the structure. Pivotal events, the few big milestones, split the story into chapters. Swimlanes separate parallel flows.
People and systems. Add who is involved and which systems they use.
Walkthrough. One person tells the story from left to right. Interrupt when something doesn't match what you know.
Reverse narrative. Walk from right to left and ask what must have happened before each event, to find missing steps.
Problems and opportunities. Add hotspots, opportunities and value wherever you see them.
Pick a problem. Everyone votes with arrows or dots on the problem to work on next.
Check-out. What did you learn, and what surprised you?
Questions to ask
What happens right before or right after this?
What triggers this? Who decides, and what do they look at?
What if it doesn't happen, happens twice or happens late?
Is this always the case, or only for some customers?
Do we all mean the same thing by this word?
Where do we gain or lose money or time?
Types of EventStorming
Big Picture: the whole business end to end, with people from many departments, over one or two days. The result is the timeline, first ideas for bounded contexts and a ranked list of problems.
Process modelling: one process from start to finish, using all the colours, in half a day to a day. It ends with a step-by-step flow and its weak spots.
Software design: business people and engineers design the software for one part of the business, down to commands, rules and screens.
How the colours connect
An actor looks at information and runs a command. If the constraints allow it, an event happens, and a policy reacts with the next command.
Words you'll hear
Domain: The part of the business we're looking at, such as online ordering.
Pivotal event: A big milestone that several departments care about, such as Order Placed.
Swimlane: A horizontal lane on the paper roll for one department or a parallel flow.
Bounded context: An area of the business where each word has one meaning. A change in meaning often marks a border.
After the session
Someone photographs the wall and shares the pictures.
Each important hotspot gets an owner and a follow-up.