Process Automation with Domain-Driven Design @ Navigate 2021

In this talk I discuss the application of “strategic” and “tactical” patterns and best practices from domain-driven design to software projects for the automation of business processes - with or without the use of workflow engines. I will show that the two different worlds - “DDD” and “Workflow” - which appear to be very different and often look at each other with skepticism - have much more in common than not - but if and only if they are cleverly linked.

Transcript

1. BPMN
   DDD
   Process Automation with Domain-Driven Design
   © Martin Schimak – plexiti GmbH – All rights reserved
   

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2. This is our automated process!
   Process
   starts!
   Make
   decision
   Check
   HUMAN
   REJECT!
   FRAUD_S
   ERVICE
   ANTI
   pattern
   

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3. After five sprints, it finally works!
   RAUD_S
   ERVICE
   Check
   GET
   invoice
   POST
   negative
   amount
   Process
   ends.
   REJECT!
   Yes
   No
   ANTI
   pattern
   

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4. You got it?
   

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5. Eric Evans, 2004
   

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6. 2004 2006 2008 2018
   2010 2012 2014 2016
   ?
   DDD … is not a book! It
   only started as a book.
   2020
   

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7. Applying DDD to
   Process Automation
   …
   

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8. Process Automation
   "Done Right"
   

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10. 2) Strategic
    Design
    The three pillars of Domain-Driven Design
    3) Modeling
    in Code
    1) Collaborative
    Modeling
    1) Collaborative
    Modeling
    

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11. "Ubiquitous" Language
    DDD emphasizes the
    importance of language
    for modeling
    executable software.
    

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12. Stop nitpicking about "labeling"!
    Process
    starts!
    Make
    decision
    Check
    HUMAN
    REJECT!
    FRAUD_S
    ERVICE
    ANTI
    pattern
    

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13. Healthily obsess with language!
    Process
    starts!
    Make
    decision
    Check
    HUMAN
    REJECT!
    FRAUD_S
    ERVICE
    DDD
    Paradigm
    Invoice
    dispute
    raised
    Determine
    dispute handling
    strategy
    Economic
    relevance? Low:
    automatic
    handling
    Higher:
    manual
    handling
    Check
    invoice dispute
    Approved
    Approved
    Rejected
    Determine
    fraud
    potential
    Partially
    approved
    Partially
    rejected
    Dispute
    approved?
    Determine
    dispute handling
    strategy
    Check
    invoice dispute
    Determine
    fraud
    potential
    

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14. Healthily obsess with language! DDD
    Paradigm
    

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15. Think.
    Together.
    

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16. "Handing over" diagrams. ANTI
    pattern
    Analyst Developer Tester
    

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17. In DDD modeling is collaborative
    DDD emphasizes the
    importance of developing
    a shared mental model.
    DDD
    Paradigm
    

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18. You need workshop methods which enable
    everybody in a meeting room to contribute
    

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19. Understand the bigger picture of your domain!
    EVENTSTORMiNG
    

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20. Events (and more) on a timeline
    Something
    business relevant
    happened!
    Invoice
    dispute
    raised
    Invoice
    dispute
    approved
    Invoice
    dispute
    rejected
    Time
    

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21. Useful for process automation projects?
    Invoice
    dispute
    raised
    Invoice
    dispute
    approved
    Invoice
    dispute
    rejected
    Invoice
    dispute
    checked
    Yes!
    Time
    

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22. EVENTSTORMiNG
    Understand the bigger picture of your domain!
    

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23. Easily explore specific domain scenarios!
    EVENTSTORMiNG
    

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24. Useful for process automation projects?
    Invoice
    dispute
    raised
    Invoice
    dispute
    approved
    Invoice
    dispute
    rejected
    Invoice
    Check
    Fraud Detection Service Design sophisticated
    collaboration models
    with your domain
    experts
    Yes!
    

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25. Easily explore specific domain scenarios!
    

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26. storystorming.com
    

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27. 2) Strategic
    Design
    The three pillars of Domain-Driven Design
    3) Modeling
    in Code
    1) Collaborative
    Modeling
    2) Strategic
    Design
    

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28. Violating responsibility boundaries ANTI
    pattern
    Customer
    Care
    Fraud
    Prevention
    Billing
    

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29. Central orchestration
    Customer
    Care
    Fraud
    Prevention
    Billing
    Invoice
    Dispute
    ANTI
    pattern
    

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30. Subdomains & Bounded Contexts DDD
    Paradigm
    Customer
    Care
    Invoice
    Dispute
    Fraud
    Prevention
    Fraud
    Detection
    Billing
    Invoicing
    Crediting
    API
    C/S
    C/S
    C/S Internal
    Customer-
    Supplier
    Relationship
    

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31. Invoice Dispute Process (in Customer Care)
    

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32. Fraud Detection Process (in Fraud Prevention)
    

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33. Crediting Process (in Billing)
    

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34. Universal enterprise-wide model
    Customer
    Care
    Fraud
    Prevention
    Billing
    ANTI
    pattern
    

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35. Defined language boundaries DDD
    Paradigm
    Customer
    Care
    Fraud
    Prevention
    Billing
    API
    

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36. DDD's
    "ubiquitous language"
    is NOT universal
    

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37. Bounded contexts for models DDD
    Paradigm
    Customer
    Care
    Fraud
    Prevention
    Billing
    API
    

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38. 2) Strategic
    Design
    The three pillars of Domain-Driven Design
    3) Modeling
    in Code
    1) Collaborative
    Modeling
    3) Modeling
    in Code
    

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39. Search!
    Close!
    Jump!
    Customer
    Care
    Fraud
    Prevention
    Billing
    ANTI
    pattern
    Process controls other services
    

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40. Process automation IMPLEMENTS
    non-atomic, asynchronous services
    

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41. Processes implement a service DDD
    Paradigm
    Customer
    Care
    Fraud
    Prevention
    Billing
    API
    

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42. Intention revealing interfaces DDD
    Paradigm
    Billing
    API
    

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43. Synchronous interfaces
    Billing
    Sync
    API
    Customer
    Care
    What looks like a
    simple, fast and
    atomic operation
    today, can tomorrow
    turn out to be …
    ANTI
    pattern
    

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44. A long-running, async business operation
    

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45. Asynchronous interfaces
    Billing
    Async
    API
    Customer
    Care
    Feed
    Async APIs will NOT
    break, if you later need
    more than just a
    simple, fast, atomic
    operation to implement
    

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46. Objects & code inside the process
    Do not mix domain objects or
    domain code into your process model
    • No type safety or code completion!
    • Editing code in vendor-specific modelers? Nah.
    • Difficult or even impossible to test :-(
    • Complex domain objects as JSON ... seriously?
    process +
    objects +
    code
    Crediting
    ANTI
    pattern
    

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47. Processes as aggregates
    Model the
    process flow in a
    visual form
    1
    DDD
    Paradigm
    Invoice Dispute Process
    Model the
    domain objects
    in code
    2
    Invoice Dispute Root Entity
    3
    Bind them 1:1
    and transition
    them as an
    aggregate
    1
    1
    ${root}
    

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48. Chaotic consistency boundaries ANTI
    pattern
    Update with an
    ACID transaction
    A
    B
    

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49. Defined consistency boundaries DDD
    Paradigm
    Update with an
    ACID transaction
    B
    A
    Aggregates
    Strong consistency
    Eventual consistency
    

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50. BPMN DDD
    Well-designed processes can be seen as aggregates?
    

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51. Thank you!
    BPMN
    DDD
    Process Automation with Domain-Driven Design
    © Martin Schimak – plexiti GmbH – All rights reserved
    

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