Agile Estimation
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The document discusses the challenges and techniques of agile estimation in project management, emphasizing the importance of iterative re-estimation and user story-based planning. It highlights common pitfalls in traditional estimation methods and introduces tools like planning poker and story points to improve accuracy and flexibility. The author, Stephen Forte, shares insights from his experience as a Chief Strategy Officer and agile practitioner, along with recommended readings on the topic.
Agile Estimation
- 1. Agile Est timation Stephen Forte stevef@orcsweb.com http://stephenforte.net
- 2. Bio Bi Chief Strategy Officer of Telerik gy Certified Scrum Master Active in the Community: International Conference Spea aker for 12+ Years RD, MVP and INETA Speaker Co‐moderator & founder of N d f d f NYC .NET Developers Group http://ww ww.nycdotnetdev.com Wrote a few books: SQL Serve er 2008 Developers Guide (MS Press) MBA from the City University of New York Past: CTO and co‐Founder of Corze en, Inc. (TXV: WAN) CTO of Zagat Survey
- 5. Estimation Wikipedia: Estimation is th he calculated approximation of a result which is usable e even if input data may be incomplete or uncertain. Problem is that estimates becom me a unbreakable schedule, where me a unbreakable schedule where any deviation is considered bad d
- 6. Problem #1 with h Estimates Estimate for our project: 1 month for design and archit t th f d i d chitecture 4 months for developmen nt 1 month for testing h f i Scenario: Your first estimate is wron ng by 1 week (design) What do you do?
- 7. The Estimation P Problem When you come up with a project idea, your first estimate is off by +/ 4x Not enough details are kn nown Traditionally too much tim i T diti ll t h time is spent on building a t b ildi specification which is not c complete Again, not enough details k A i t h d t ils are known As time progresses, more d details emerge about the system and its details t d it d t il The cone of uncertainty
- 9. Real life story From Zagat.com in .com bo oom Project was “late” due to no j o re‐estimation and emerging requirements Daily status meeting with C y g CEO on the MS Project plan j p Patrick has 5 tasks for this w week, each estimated for 1 day each Patrick comes to you and s says I am going to spend 3 days writing a code gen uti y y g g ility and one day testing it y g then on Friday, all of my ta asks will be done with a button push Try explaining that to the C CEO!
- 11. g Agile Estimation n Wikipedia: Estimation is th he calculated approximation of a result t which is usable even if input data may be incompl lete or uncertain. Problem is that estimates become a unbreakable schedule, where any deviaation is considered bad Agile Estimation throws th his logic away and always re‐ his logic away and always re estimates a project after ea ach iteration Different value system, de Different value system de eviations are not deviations, eviations are not deviations they are more accurate est timations Uses the cone of uncertain nty to your advantage
- 12. How to Estimate e User Stories Planning Poker Pl i P k Story Points Product Backlog Velocity Re‐estimation
- 13. User Stories Users break down the func ctionality into “User Stories” User Stories are kept small U S i k ll User Stories include accepttance criteria
- 14. g Planning Poker After all the user stories are e written, get a list of stories and do a high level estimat te Estimate is for setting prio orities, not schedule NOT a time based estimati NOT ti b d ti ti ion i Super hard, Hard, Medium m, Easy, Super easy Done by consensus To get there you play planning poker Why? No pressure.
- 15. y Story Points Break down user stories to units of relative size So you can compare featur S f t res Alternative to time Story Points are not a meas S i surement of duration, but f d i b rather a measurement of si ize/complexity Start with 1 standard featur re and then other features are either 1x, 2x, etc larger o or smaller than that relative feature in size/complexity f t i i / l it
- 16. Product Backlog g All story points are put into o a bucket This represents all of the ta k f h j ( Thi ll f h asks for the project (work k items) Backlog will have an item a d i i B kl ill h i and its estimate Remember this estimate is s not time based, but point based b d Backlog can also contain th he priority
- 17. A sample product backlog A sample product backlog Backlog item m Estimate Allow a guest to make a rese ervation 3 As a guest, I want to cancel a reservation. 5 As a guest, I want to changee the dates of a 3 reservation. As a hotel employee, I can r run RevPAR 8 reports (revenue‐per‐availaable‐room) Improve exception handling g 8 ... 7 Total 50
- 18. p Sprint 1 Developers will commit to XX story points Warning, they will usually W i h ill ll over commit i After the end of sprint 1, yo ou have your first velocity number b
- 19. y Team Velocity Velocity is the number of s story points per sprint completed You calculate velocity to prredict how much work to commit to in a sprint Velocity only works if you e estimate your story points consistency consistenc Over time you will know: t team has a velocity of 32 story points per sprint t i t i t Over time this will self‐correct Over time you will be able di h j O i ill b ble to predict the project schedule (and release)
- 20. g Calculating Team y m Velocity Select a regular time periodd (sprint) over which to measure Velocity Add up the story point estiimates 100% completed At the end of the sprint, th A h d f h i h fihe figure you have is your h i Velocity You can then use your Velo h locity as a basis for your b f future commitments
- 22. Re‐estimation As you complete more spri ints, your velocity will change Velocity changes because of minor inconsistencies in the story point estimates Team velocity will typicall ly stabilize between 3 and 6 iterations Re‐estimation of the entire e project happens after each sprint New Velocity New story points added an nd removed (completed) Use the cone!
- 24. Tons of Tools I prefer user stories to be on paper Can transcribe to Excel C t ib t E l Do NOT create VSTS work k items until you have all of the user stories estimated
- 25. Visual Studio Tea y am System Scrum templates Story points become work S i b k items i
- 28. Reading List R di Li Books I have read and recom B k I h d d mmend:d User Stories Applied by Mike e Cohn Agile Estimating and Plannin by Mike Cohn ng Agile Retrospectives by Esthe er Derby and Diana Larsen