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Planning with #NoEstimates

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Introduction and exercises

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Planning with #NoEstimates

  1. 1. @gil_zilberfeld Planning with #NoEstimates
  2. 2. @gil_zilberfeld Hello! I AM GIL ZILBERFELD www.gilzilberfeld.com www.everydayunittesting.com @gil_zilberfeld
  3. 3. @gil_zilberfeld That is the question
  4. 4. @gil_zilberfeld The founders
  5. 5. @gil_zilberfeld Why do we need estimates?
  6. 6. @gil_zilberfeld Ask the expert
  7. 7. @gil_zilberfeld Why do we want estimates?
  8. 8. @gil_zilberfeld Better decisions Go / No / Not now Alternatives Be in control
  9. 9. @gil_zilberfeld Why don’t we like giving estimates?
  10. 10. @gil_zilberfeld Treated as commitments Inflated Waste of time
  11. 11. @gil_zilberfeld The main problem is…
  12. 12. @gil_zilberfeld Do they help make better decisions?
  13. 13. @gil_zilberfeld We’re not good at estimating
  14. 14. @gil_zilberfeld “Prediction is very difficult, especially about the future.” Niels Bohr, Nobel Prize in Physics
  15. 15. @gil_zilberfeld The cone of uncertainty
  16. 16. @gil_zilberfeld “It always takes longer than you expect, even when you take into account Hofstadter's Law” Douglas Hofstadter Professor of cognitive science
  17. 17. @gil_zilberfeld The estimation game For each of the next 10 quantitative questions, give a lower and an upper bound, such that you believe with about 90% certainty that the correct answer lies within the interval given.
  18. 18. @gil_zilberfeld The estimation game This means that you should expect to guess correctly for about 9 questions out of 10.
  19. 19. @gil_zilberfeld Q: How many people are in this room? A: You ‘guess’ an interval: 2-100
  20. 20. @gil_zilberfeld Ready?
  21. 21. @gil_zilberfeld 1. What was the date of birth of Bram Stoker, author of Dracula?
  22. 22. @gil_zilberfeld 2. What is the population of the Republic of Brazil?
  23. 23. @gil_zilberfeld 3. What is the height, in meters, of the tallest living redwood tree?
  24. 24. @gil_zilberfeld 4. How many standardized (ISO 6346) steel shipping containers exist in the world?
  25. 25. @gil_zilberfeld 5. How many Boeing 747 (all models) have been built at this date?
  26. 26. @gil_zilberfeld 6. What is the total number of human deaths attributed to H5N1 “avian” flu?
  27. 27. @gil_zilberfeld 7. How many Syrian conflict refugees were registered by UNHCR as of 1 Nov 2012?
  28. 28. @gil_zilberfeld 8. What was the total wine production of France in 2009, in hectoliters?
  29. 29. @gil_zilberfeld 9. How many Olympics medals altogether have been won to date by Austrian athletes?
  30. 30. @gil_zilberfeld 10. What is the half-life, in years, of the isotope Plutonium 239?
  31. 31. @gil_zilberfeld 1) 1847 2) 199 million 3) 115 meters 4) 20 million containers 5) 1486 747s You can also split your content 6) 379 deaths 7) 286,000 refugees 8) 45 million hectoliters 9) 304 medals 10) 24 thousand years How did you do?
  32. 32. @gil_zilberfeld So what happened?
  33. 33. @gil_zilberfeld I’ll tell you
  34. 34. @gil_zilberfeld This is what I want
  35. 35. @gil_zilberfeld “The primary purpose of an estimate is not to predict a project’s outcome. Steve McConnell, Software Estimation (2006) It is to determine whether a project’s targets are realistic enough to allow the project to be controlled to meet them.”
  36. 36. @gil_zilberfeld Let’s assume and estimate costs!
  37. 37. @gil_zilberfeld Estimates are not the only tools
  38. 38. @gil_zilberfeld Trains!
  39. 39. @gil_zilberfeld What else?
  40. 40. @gil_zilberfeld Value estimation
  41. 41. @gil_zilberfeld Let’s estimate value!
  42. 42. @gil_zilberfeld It’s not that simple
  43. 43. @gil_zilberfeld Liz Keogh’s complexity model 1. Just about everyone in the world has done this. 2. Lots of people have done this, including someone on our team. 3. Someone in our company has done this, or we have access to expertise. 4. Someone in the world did this, but not in our organization (and probably at a competitor). 5. Nobody in the world has ever done this before.
  44. 44. @gil_zilberfeld Let’s estimate complexity!
  45. 45. @gil_zilberfeld History is your friend
  46. 46. @gil_zilberfeld Small, same-size batches
  47. 47. @gil_zilberfeld Let’s break it down!
  48. 48. @gil_zilberfeld A few more things…
  49. 49. @gil_zilberfeld Assume you are ignorant
  50. 50. @gil_zilberfeld Write them down!
  51. 51. @gil_zilberfeld “Ignorance is the single greatest impediment to throughput.” Dan North https://dannorth.net/2010/08/30/introd ucing-deliberate-discovery/
  52. 52. @gil_zilberfeld Let’s plan experiments!
  53. 53. @gil_zilberfeld We don’t need no stinking estimates! ANY QUESTIONS? You can find me at: @gil_zilberfeld http://www.GilZilberfeld.com http://www.EverydayUnitTesting.com

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