Software Project Estimation Techniques

Presentation from the Daycamp4Developers virtual conference talking about how to estimate for software projects, and how to keep track of how those estimations are working out.

Transcript

1. Software Project
   Estimations
   Lorna Mitchell, Day Camp for
   Developers 6
   

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2. How Late??
   

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3. Is Estimating Important?
   

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4. Is Estimating Important?
   • One of the two most common causes of
   runaway projects is unstable requirements
   

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5. Is Estimating Important?
   • One of the two most common causes of
   runaway projects is unstable requirements
   • One of the two most common causes of
   runaway projects is optimistic estimation
   (from IEEE: http://lrnja.net/10DRtB4)
   

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6. Is Requirements Gathering
   Important?
   

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7. Only if you want to build something
   your client actually wants
   

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8. Project Requirements
   Requirements are not just about the features.
   Consider:
   • resource and/or cost
   • deadlines
   • platform constraints
   

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9. Estimations
   Recipe for good estimations:
   • Clear, stable requirements
   • Feedback loop
   • Ability to change the plan
   

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10. User Stories
    Capture a single action requirement and it's
    motives
    Template:
    As a , I want so that
    
    

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11. Example User Stories
    • As a user, I want to see details of a talk so I
    can find out about it
    • As an admin, I want to be able to edit
    details of a talk so I can make changes
    • As a speaker I want to be able to claim a
    talk so it will be listed on my account
    • As a user, I want to rate and comment on a
    talk so that I can give feedback to the
    speaker
    

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12. Ground Rules of Estimation
    

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13. Ground Rules of Estimation
    • Only a person capable of completing a task
    can estimate it
    • If a task is estimated at more than half a
    day, the task should be split
    • If a task cannot be estimated, steps should
    be taken to reduce the unknowns
    

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14. Estimation Techniques
    

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15. Traditional Method
    

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16. Planning Poker
    Uses the wisdom of crowds to get an accurate
    estimate.
    

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19. Planning Poker
    Uses the wisdom of crowds to get an accurate
    estimate.
    You will need:
    • 3+ players and a facilitator
    • Detailed list of tasks
    • Deck of Planning Poker cards, or equivalent
    

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20. How To Play Planning Poker
    • Take each task in turn
    • Facilitator describes the task
    • At a signal, players estimate
    • Estimates are close, use average
    • If estimates differ, task is too vague
    • Quickly redefine and re-estimate
    

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21. How To Run A Meeting
    • If you are leading it, then LEAD
    • Prepare an agenda
    • Observe timings
    • Curtail other discussion
    

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22. What's Missing?
    Commonly forgotten tasks include:
    • Data migration
    • Copy management
    • Client demo time
    • Server setup
    • Handover documentation
    

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23. The Flaw In The Plan: Reality
    

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24. Guide motto: Be Prepared
    

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25. Risk
    Risks deserve our recognition and respect
    Try to mitigate risks:
    • Identify them
    • Single points of failure: look for
    alternatives/redundancy
    • Unknowns: "spike" to reduce the unknown
    aspect
    

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26. Tracking Estimates
    

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27. Tracking Estimates
    Each task has an estimate
    • After working on a task, re-estimate how
    much work is left in that task
    • When it's done, estimate goes to zero
    • Track these per-day to get burndown chart
    

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28. Example Task List
    Task Owner Mon Tue Wed Thu Fri
    Buy drinks Kevin 3 3 3 3 0
    Make cake Lorna 2 0 0 0 0
    Make sandwiches Lorna 6 6 4 3 0
    Set table Lorna 2 2 2 2 0
    Decorate Cake Lorna 7 7 7 5 2
    

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29. Example Burndown Chart
    

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30. Project Velocity: a freakishly reliable
    figure showing the disparity between
    estimated and actual work rates
    

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31. Measuring Project Velocity
    As well as updating estimates, track time spent
    per task.
    For completed tasks, divide estimate/actual to
    get velocity.
    Use as a multiplier to correct future estimations
    

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32. Alternative Velocity Measure
    Agile teams working in sprints can measure
    story points per sprint
    

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33. How to Deliver a Project on
    Time
    • Make excellent estimates
    • Work out how much time there is
    • Schedule in a plan
    • Measure progress
    • Adjust as required
    

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34. Estimations
    

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35. Estimations
    • Estimations are important
    • Accurate estimations are achievable
    • We continue to estimate and inform during
    a project
    

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36. Go Forth and Deliver On Time
    

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37. Thankyou!
    Any questions?
    Feedback: https://joind.in/8973
    Me: http://lornajane.net
    

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