EventStorming, BDD and sick teachers!

A little workshop about "Exploring behaviour before structure".
@martinschimak and @paulroho -> June 22nd, 2018 -> DDDesign Vienna

Transcript

1. Exploring behaviour before structure.
   @martinschimak and @paulroho -> June 22nd, 2018 -> Domain-Driven Design Vienna
   EventStorming, BDD and sick teachers!
   

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2. Do you still remember school? And escaping its „structural model“! :-)
   

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3. Mon Tue Wed Thu Fri
   8:00 – 8:50 Mathematics
   Christiane Lorch
   Sports
   Mathias Wils
   English
   Stefanie Keller
   Vocals
   Reinhold Kneer
   History
   Tobias Puth
   8:55 – 9:45 Ethics
   Arnold Unger
   Sports
   Mathias Wils
   History
   Tobias Puth
   Vocals
   Reinhold Kneer
   French
   Monique Perron
   9:55 – 10:45 French
   Monique Perron
   English
   Stefanie Keller
   Music
   Heidi Sokolowski
   Biology
   Tatjana Nelles
   Geography
   Fabio Baie
   10:50 – 11:40 German
   Julian Wellner
   French
   Monique Perron
   Mathematics
   Christiane Lorch
   Music
   Heidi Sokolowski
   German
   Julian Wellner
   11:55 – 12:45 Music
   Heidi Sokolowski
   German
   Julian Wellner
   French
   Monique Perron
   English
   Stefanie Keller
   German
   Julian Wellner
   12:50 – 13:40 Music
   Heidi Sokolowski
   - Ethics
   Arnold Unger
   Mathematics
   Christiane Lorch
   Mathematics
   Christiane Lorch
   5c - 2017/18 International Music Highschool 1090 Vienna
   

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4. Group brainstorming: How do we call the
   structural elements we find in a school‘s timetable?
   

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5. Structural models don‘t convey what HAPPENS going through time.
   

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6. Events? Something happened!
   Teacher
   absence
   reported
   

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7. Quick group brainstorming: who
   is affected by such an event?
   Teacher
   absence
   reported
   

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8. More brainstorming leads to more events!
   Teacher
   absence
   reported
   Substitute
   informed
   Lesson
   canceled
   Parents
   informed
   

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9. Policies… when decisions need to be made!
   Teacher
   absence
   reported
   Substitute
   informed
   Lesson
   canceled
   Parents
   informed
   Substitutes
   decision
   

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10. Substitute
    informed
    Lesson
    canceled
    Parents
    informed
    Substitutes
    decision
    Commands... when decisions need to be executed!
    Cancel
    lesson
    Inform
    substitute
    Teacher
    absence
    reported
    

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11. Group EventStorming: What would need to happen when it happens?
    Teacher
    absence
    reported
    

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12. Quick question: what triggers you to add a new sticky or remove one?
    

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13. Describing software behaviour with Gherkin
    GIVEN a state to be assumed
    WHEN we trigger a change
    THEN we will observe an expected result Verify
    Setup
    Execute
    

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14. A policy. And a possible rule detailing it.
    - Preferredly, teachers that teach a class in another
    subject are chosen to substitute absent teachers.
    - …
    Substitutes
    decision
    

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15. Gherkins to describe rules detailing a policy
    GIVEN a set of events happened
    WHEN another event happens
    THEN a command will follow – or not Command
    Decision
    rules
    Domain
    event
    Domain
    event
    Domain
    event
    

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16. Group work: When looking at your policies,
    what would be specific scenarios (expressed as
    examples) illustrating one of the decision rules?
    

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17. FEATURE: Substitutes Decision. Policy to decide who shall substitute an absent teacher.
    SCENARIO: Preferredly, teachers that teach a class in another subject are chosen to substitute absent teachers.
    GIVEN the following teachers are assigned to teach 5c:
    | Teacher | Subject |
    | Christiane Lorch | Mathematics |
    | Julian Wellner | German |
    AND 5c has a mathematics lesson scheduled
    on Wednesday 10:50 to 11:40
    AND Julian Wellner is reserved as substitute
    on Wednesday 10:50 to 11:40
    WHEN Christiane Lorch reports her absence
    THEN Julian Wellner shall substitute
    Christiane Lorch on Wednesday 10:50 to 11:40 Substitute
    lesson
    Substitutes
    decision
    Teacher
    absence
    reported
    Teacher
    assigned
    to class
    Lesson
    scheduled
    for class
    Teacher
    assigned to
    teach class
    Teacher
    reserved as
    substitute
    

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18. Gherkins to describe rules when executing a command
    GIVEN a set of events happened
    WHEN a command executes
    THEN another event will happen – or not
    Command
    Consistency
    rules
    Domain
    event
    Domain
    event
    Domain
    event
    

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19. FEATURE: Substitute lesson. A teacher shall be assigned to substitute for a specific lesson.
    SCENARIO: A substitute teacher must not be assigned to conflicting duties.
    GIVEN Julian Wellner is assigned to substitute
    Arnold Unger on Monday 08:00 to 08:50
    WHEN Julian Wellner shall substitute
    Christiane Lorch on Monday 08:00 to 08:50
    THEN Julian Wellner will not be assigned to substitute
    Christiane Lorch on Monday 08:00 to 08:50
    Substitute
    lesson
    Teacher
    assigned to
    substitute
    Teacher
    assigned to
    substitute
    

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20. Gherkins to describe rules for creating a report
    GIVEN a set of events happened
    WHEN another event happens
    THEN a report will reflect the expected state
    Projection
    rules
    Domain
    event
    Domain
    event
    Report
    

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21. FEATURE: Time table. Report reflecting the actual lessons scheduled for a specific class.
    SCENARIO: A substitution is reflected in the time table for the affected class.
    GIVEN Christiane Lorch is assigned to teach
    mathematics in 5c
    AND 5c has a mathematics lesson scheduled
    on Wednesday 10:50 to 11:40
    WHEN Julian Wellner substitutes
    Christiane Lorch on Wednesday 10:50 to 11:40
    THEN 5c time table will reflect Julian Wellner as
    substitute on Wednesday 10:50 to 11:40
    AND 5c time table will reflect a german lesson scheduled
    on Wednesday 10:50 to 11:40
    Teacher
    assigned to
    substitute
    Time
    table
    Lesson
    scheduled
    for class
    Teacher
    assigned to
    teach class
    

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22. Mon Tue Wed Thu Fri
    8:00 – 8:50 Mathematics
    Christiane Lorch
    Sports
    Mathias Wils
    English
    Stefanie Keller
    Vocals
    Reinhold Kneer
    History
    Tobias Puth
    8:55 – 9:45 Ethics
    Arnold Unger
    Sports
    Mathias Wils
    History
    Tobias Puth
    Vocals
    Reinhold Kneer
    French
    Monique Perron
    9:55 – 10:45 French
    Monique Perron
    English
    Stefanie Keller
    Music
    Heidi Sokolowski
    Biology
    Tatjana Nelles
    Geography
    Fabio Baie
    10:50 – 11:40 German
    Julian Wellner
    French
    Monique Perron
    German
    Julian Wellner
    Music
    Heidi Sokolowski
    German
    Julian Wellner
    11:55 – 12:45 Music
    Heidi Sokolowski
    German
    Julian Wellner
    French
    Monique Perron
    English
    Stefanie Keller
    German
    Julian Wellner
    12:50 – 13:40 Music
    Heidi Sokolowski
    - Ethics
    Arnold Unger
    Mathematics
    Christiane Lorch
    Mathematics
    Christiane Lorch
    5c - 2017/18 International Music Highschool 1090 Vienna
    

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23. Group discussion: What do you think about relating
    EventStorming results to Gherkin example scenarios?
    

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