Event Storming Workshops: A Closer Look at Different Approaches

Event Storming serves as a strategic approach to gain a comprehensive understanding of the business domain, aiming to unveil as many uncertainties and complexities as possible prior to initiating design and implementation. Each phase of this process demands varying degrees of detail and breadth of information. At times, a broad overview suffices, while certain scenarios necessitate an in-depth exploration of the intricate aspects of specific requirements.

Preparing for Your Event Storming Workshop

Who to Invite?

A successful workshop hinges on three participant groups:

• Those who knows answers - Domain experts, business analysts, and others who can elucidate domain nuances, rules, and policies. Their expertise is crucial for understanding business operations and the language that articulates its activities.
• Those who asks questions - Developers, testers, and all those who are involved in implementation whose probing questions uncover less apparent domain facets. Their curiosity enriches business understanding.
• Facilitator - Typically one individual, or more for larger groups, tasked with steering the workshop towards its objectives while keeping participants engaged and focused.

In addition, there are two crucial considerations to keep in mind:

• Don't get overfixated with the list of roles I provided above. Focus on the individuals who possess knowledge and those who are curious and want to learn. It’s not uncommon for the most knowledgeable person, the one who has all the answers, to be a senior developer with years of experience in the business.
• Understand that the delineation between groups is not rigid. Participants may find themselves providing answers in one instance and generating questions in another, reflecting the collaborative and evolving nature of the workshop. 

Before Sending Invites

• Define the goal - Clarity on workshop objectives prevents aimless drift and keeps discussions on track.
• Ensure you don’t overlook essential participants - Be certain to invite that critical individual whose opinions and decisions matter. Confirm their attendance promptly, and if necessary, directly communicate with them. Avoid the frustration of discovering inaccuracies or the need for revisiting decisions days after a workshop by proactively addressing this upfront.

Preparation Checklist

• Snacks and drinks - For onsite workshops, ensure that snacks and beverages are readily available in the room. For virtual sessions, remind participants in the invitation to have refreshments on hand. The reason? A boost of sugar can energize discussions, and a simple cookie might just be the fuel needed to reach a conclusion. Moreover, hunger can significantly detract from concentration, so it’s best to address it beforehand to maintain focus.
• Onsite workshop
  • Sticky notes - Stock an ample variety in size, color, and shape to represent different information types.
  • Writing tools - Opt for markers with thick tips to ensure each note conveys a single, clear message.
  • Space - Secure a lengthy wall space for note placement—there’s no such thing as too long.
• Remote Workshop - Select a tool that allows for the creation of diverse shapes and the addition of annotations. While constraints and policies sometimes have led me to utilize tools like Visio, draw.io, and Paint, my preferred option is Miro.

The Legend

For participants experienced with Event Storming, display the legend on the wall prior to the workshop. This visual aid will serve as a quick reference, helping them recall the significance of each color, shape, and size.

Conversely, when introducing newcomers to Event Storming, develop the legend progressively as new information emerges. This approach saves time, as you won’t need to extensively define concepts like “Policy.” The examples and corresponding labels will naturally elucidate their meanings.

Event Storming Workshops

To accommodate the diverse needs of product development phases, Event Storming offers a three types of workshops. Each one is tailored with objectives, list of participants, a defined scope, and a depth of detail to be addressed:

• Big Picture – Designed to foster a high-level comprehension of the business domain. It is pivotal in developing a unified language, which in turn cultivates a collective comprehension among all involved. It’s also a critical juncture for identifying and delineating the boundaries within the domain.
• The workshop’s goal is not to achieve perfection or completeness, nor to present all information exhaustively. Instead, its primary focus is to surface a multitude of problems, challenges, and questions, emphasizing the identification of issues over the immediate pursuit of solutions.
• Process Level – Dedicated to meticulously examining the process to ensure its integrity. Our objective is to resolve any queries and uncertainties that could influence the process. We aim to explore every conceivable variation, encompassing both the ‘sunny day’ and ‘rainy day’ scenarios.
• Design Level – Our goal is to cover all the key aspects of the part of the process we're focused on. We want to understand it so well that developers can start coding right after the workshop.

The Big Picture

Objectives

• Achieve a broad understanding of the business domain.
• Identify and spotlight any hurdles, challenges, and unknowns.
• Foster a shared language among participants.
• Determine domains boundaries.
• Recognize key values and potential risks
• Define Bounded Contexts.

NOT Our Objectives

• Attain an exhaustive, detailed comprehension of every process.
• Provide answers to all posed questions.

Scope

Typically, we begin with an overarching view of the entire business domain. If necessary, subsequent sessions may focus on a more specific area.

Duration

Given the extensive information, the workshop can be quite lengthy. Efforts are made to ensure all participants can commit to one full day, allowing for 3-4 sessions, each lasting approximately 1.5 hours.

Participants

• A diverse group from various departments, bringing different experiences, perspectives, and roles.
• Individuals who may not interact regularly or may be unfamiliar with one another.
• Domain experts, architects, and team leaders with specialized knowledge.
• The size of the group can range significantly, from 10 to over 30 individuals.

Process Level

Objectives

• Make clear what might happen in the process.
• Gain a solid understanding of the process.
• Check that all possible situations and rules are correct.
• Answer important questions about how the process works.
• Validate Bounded Contexts

NOT Our Objectives

• Delve into the minutiae of each process step.
• Resolve questions that have no bearing on the process itself.

Scope

The focus is on the business process, including both its expected and adverse scenarios.

Duration

The workshop is expected to span 1-2 sessions, each lasting around 1.5 hours.

Participants

• Domain experts with in-depth knowledge of the process.
• Individuals actively engaged in the development of service(s) relevant to the process, such as architects, developers, and testers.

Design Level

Objectives

• Determine the necessary data for each step of the process.
• Establish the rules that need to be met throughout the process.
• Identify and define the Aggregates.

NOT Our Objectives

• Cataloging every piece of data in extreme detail—general categories like “personal data” are sufficient for now.
• Specifying every rule to the finest detail—for instance, simply stating “an address exists” is adequate at this stage.

Scope

The focus may be on a specific part or the entirety of the process, depending on its complexity.

Duration

One session, lasting between 1 to 1.5 hours.

Participants

• Experts who understand the process steps in detail.
• Team members involved in developing the relevant business area.

Final Thoughts

Event Storming is more than just a modeling technique—it's a collaborative discovery process that brings clarity to complex domains and builds shared understanding among diverse stakeholders. By selecting the appropriate workshop type and preparing thoughtfully, teams can unlock hidden insights, align on terminology, and reveal both risks and opportunities early in the development lifecycle.

Whether you're looking at the big picture, zooming into a specific process, or diving into the technical details of design, each level of Event Storming offers unique value. Embrace the messiness, encourage open dialogue, and focus on learning rather than perfection.

The best workshops are those where everyone leaves not only with answers, but also with better questions.