Agile Estimation

  • ¬†Estimation == approximation
  • everyone believe it’s final value
  • cone of uncertainty09L_2011_5day

Agile estimation

  • re-evaluate every iteration

How to estimate

Unit of Measurement

  • don’t use time as a measurement
  • name it as boss surname :)
  • Story points – relative value against baseline
    • 1x 2x 3x 5x … harder than baseline
    • unique to the team
  • Negotiation
    • not on position but be crazy about interest, why
  • several iterations are necessary

 Planning Poker

  • card with values 1/2, 1, 2, 3, 5, 8, … Fibonacci values
  • eliminate strong personalities which dominate communication
  • every team member has own cards
  • hide his estimation, revealed together
  • set baseline – for example fix of ¬†typo in resources
  • estimates whole effort (development, test, documentation, …)


  • all user stories (estimation in story points, priority)

Team velocity

  • amount of story points which has been done during previous iterations -> will settle after several iterations
  • per team -> it’s help estimate whole product timeline and deadline (more realistic)
  • bugs are added to product as a story points
  • re-estimation of entire project every iteration

What to measure

  • Product backlog size at start
  • committed sprint backlog
  • completed backlog items
  • cumulative team velocity
  • items added to backlog (forgotten features)
  • items removed from backlog
  • bugs added to backlog
  • use weighted average to know how long it will take


  • progressive allocate more % of time during iteration for bugs and reworks
  • increase during iterations