EVENTSTORMING COLLABORATIVE LEARNING FOR COMPLEX DOMAINS Paul - - PowerPoint PPT Presentation

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EVENTSTORMING COLLABORATIVE LEARNING FOR COMPLEX DOMAINS Paul - - PowerPoint PPT Presentation

Nov 03, 2023 322 likes •1.13k views

EVENTSTORMING COLLABORATIVE LEARNING FOR COMPLEX DOMAINS Paul Rayner @thepaulrayner THE LANDSCAPE Complex business rules & processes Knowledge silos Numerous diverse (& often legacy) system interactions THE CRITICAL COMPLEXITY OF

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COLLABORATIVE LEARNING FOR COMPLEX DOMAINS

EVENTSTORMING

@thepaulrayner

Paul Rayner

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THE LANDSCAPE

Complex business rules & processes Knowledge silos Numerous diverse (& often legacy) system interactions

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THE CRITICAL COMPLEXITY OF MOST SOFTWARE PROJECTS IS IN UNDERSTANDING THE DOMAIN ITSELF

Eric Evans

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SLIDE 4 HTTPS://EN.WIKIPEDIA.ORG/WIKI/ROSETTA_STONE#/MEDIA/FILE:ROSETTA_STONE.JPG
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HOW DO WE LEARN …FAST?

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https://www.drupal.org/node/1785994

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BEHAVIOUR TRUMPS STRUCTURE

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https://commons.wikimedia.org/wiki/File:Use_case_restaurant_model.svg

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https://commons.wikimedia.org/wiki/File:Activity_conducting.svg

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https://commons.wikimedia.org/wiki/File:CheckEmail.svg

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OPTIMIZE FOR SHARED LEARNING

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leanpub.com/introducing_eventstorming

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PLACE EVENTS ON A TIMELINE

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leanpub.com/introducing_eventstorming

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WHAT IS A DOMAIN EVENT?

Something that happened in the business that your domain experts care about

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leanpub.com/introducing_eventstorming

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SPECIES OF DOMAIN EVENTS

  • A step in a business process

e.g. customer order submitted, customer paid $100, order completed, item shipped.

  • Something that happens on a scheduled basis

e.g. nightly account reconciliation completed, end of month.

  • Something meaningful that occurs as a

result of something else happening

e.g. customer account locked after invalid password entered 3 times

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VISUALIZE LEARNING OPPORTUNITIES

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leanpub.com/introducing_eventstorming

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leanpub.com/introducing_eventstorming

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EVENTS & QUESTIONS FIRST

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EVENTSTORMING

A LEGACY APPLICATION

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PROVIDE UNLIMITED MODELING SPACE

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leanpub.com/introducing_eventstorming

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leanpub.com/introducing_eventstorming

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SLIDE 34 They lived happily ever after

Once upon a time…

More modeling space than you expect

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INVITE THE RIGHT PEOPLE

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Development team members and business people gather in a room and together we create a visual map

  • f the flow of events
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EVENTSTORMING

IN ACTION

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VISUALIZE INTERACTIONS

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leanpub.com/introducing_eventstorming

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leanpub.com/introducing_eventstorming

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leanpub.com/introducing_eventstorming

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VISUALIZE BUSINESS RULES

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leanpub.com/introducing_eventstorming

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PROVIDE A VISIBLE LEGEND

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Adapted from leanpub.com/introducing_eventstorming

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VISUALIZE ALTERNATE FLOWS

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Decided to Reimburse (alternate flow) Decided to Repair (main flow)

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NATURAL TRANSITION TO EVENT SOURCING

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Adapted from leanpub.com/introducing_eventstorming

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EVENT SOURCING

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Shopping Cart Item
 Added

ECommerce Context

Price
 Calculated Promotion
 Code
 Applied Item
 Added Price
 Calculated Checked
 Out

Aggregate state modeled as a sequence of domain events

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EVENT SOURCING

  • Don't save the current state of objects
  • Process events that lead to the current state
  • TDD focused on command processing

generating the correct events

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CLARIFYING CONTEXT BOUNDARIES

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Servicer Management Context Claims Context

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NATURAL TRANSITION TO DISTRIBUTED SYSTEMS

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Event Stream …

ECommerce Context

Event Stream …

Order Management
 Context

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FACILITATION TIPS

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EVENTSTORMING FACILITATION TIP #1

Focus first on learning and understanding

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CLARIFYING QUESTIONS

  • “What circumstances would cause ... to

happen?”

  • “What was the path that led us here?”
  • “What is a good example of …?”
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CLARIFYING QUESTIONS

  • "What do you mean by …?"
  • "What might lead someone to do/need …?”
  • "What else might happen…?
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EVENTSTORMING FACILITATION TIP #2

Anchor to a concrete business example

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EVENTSTORMING FACILITATION TIP #3

Clarify fuzzy concepts and language

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Command is “Open Claim” What should associated event be called?

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EVENTSTORMING FACILITATION TIP #5

Conversations and examples are primary

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EVENTSTORMING FACILITATION TIP #6

Post first, Ask questions later

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EVENTSTORMING FACILITATION TIP #4

Timebox

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POSSIBLE LIMITATIONS

  • Simple business domains (e.g. CRUD)

and/or systems

  • Distributed teams
  • Larger group/greater complexity =

better facilitation

  • ???
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WHY EVENTSTORMING?

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WHY EVENTSTORMING?

Collaborative learning

Cultivate mutual shared understanding Uncover misunderstandings & missing concepts Avoid rework

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WHY EVENTSTORMING?

Model & explore complex domains

Visual, tactile representation of system behaviour & outcomes Smoother transition to a rich domain model, design and coding

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QUESTIONS?

@thepaulrayner

Paul Rayner

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THANKS!

@thepaulrayner

Paul Rayner