Mikado Method: A structured method for significant changes in complex code

Transcript

1. Mikado Method
   A structured method for significant changes in complex code
   

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2. Change in a jungle of
   dependencies, broken
   code and undocumented
   features
   

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3. 1. Set a goal
   Represent a starting point, and know when you are done.
   

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4. 2. Experiment
   Make a simple change and see what breaks.
   

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5. 3. Visualize
   Create a dependency graph of steps required to achieve the goal.
   

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6. site is implemented, you can note it in the graph with a check mark, as in figure 1.8.
   Mikado
   Goal
   Prerequisite: Immediate
   solution to errors when implementing
   Mikado Goal
   The Mikado Goal
   can have several direct
   prerequisites
   Add more
   prerequisites...
   ...linked to
   the previous
   Prerequisites can
   have common
   dependencies
   There can be lots
   of such dependent
   changes needed
   Figure 1.8 Check off the solutions as they are completed.
   

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7. 4. Undo
   Revert changes after each experiment. Always experiment in a working state.
   

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8. Case Study
   Support SEPA in invoicing and payment application
   

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9. SEPA
   incasso
   

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10. SEPA
    incasso
    create
    processor
    

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11. SEPA
    incasso
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    

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12. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    

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13. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    

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14. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    

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15. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    parse
    stored
    amounts
    move
    parse to
    processor
    

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16. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    parse
    stored
    amounts
    move
    parse to
    processor
    

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17. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    parse
    stored
    amounts
    move
    parse to
    processor
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    

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18. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    parse
    stored
    amounts
    move
    parse to
    processor
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    

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19. SEPA
    incasso
    allow
    uploads
    create
    processor
    parse
    SEPA files
    add
    transaction
    fields
    show
    SEPA
    fields
    extract
    display
    logic
    store
    amounts
    parse
    stored
    amounts
    move
    parse to
    processor
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    ✔
    

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20. Benefits
    • Keep a stable code base.
    • Track progress.
    • Enables collaboration.
    • Increases communication.
    • Very light-weight.
    

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21. You need tests
    

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22. The Mikado Method
    Ola Ellnestam and Daniel Brolund
    http://www.manning.com/ellnestam
    

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