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About estimating and planning
- 1. Bart Vanderbeke -- the art of estimating and planning violin maker: Thomas Meuwissen https://www.thomasmeuwissen.com/ Photo: Rudi Van Beek (http://www.rudivanbeek.be) Craftsmanship: The Art of Estimating and Planning Bart Vanderbeke
- 2. Bart Vanderbeke -- the art of estimating and planning Bart Vanderbeke CRAFTSMANSHIP CRAFTSMANSHIP EMPLOYABILITY CAPABILITY Train people well enough, so they can leave, treat them well enough, so they don’t want to Richard Branson The professionalism I show in my job will allow me to find a new job easily if I were to leave my job. ‘I’ on the slides is you listening to this presentation… I have the skills or build the skills to do my current job professionally. (technology, methods, process,…) ©ARAK7
- 3. Bart Vanderbeke -- the art of estimating and planning • Choosing the optimal tool… • Implies you know more than one tool (*) • Having a well-filled toolbox… • Makes you more valuable for your employer • Makes you more employable • Use your employability in another company as trigger, crowbar to keep on learning (*) Tool: method, toolchain, design approach, language,… What’s in your toolbox? Law of the Instrument koevoet
- 4. Bart Vanderbeke -- the art of estimating and planning Working in the 21st century
- 5. AESTIMOLOGY
- 6. Bart Vanderbeke -- the art of estimating and planning Estimation process Study Estimate Challenge Study Estimate insight insight number number Personal insight Personal insight Collective Insight Requirements Assumptions Fact or Fiction fact fiction THE Number ’12’ ’19’ Decide
- 7. Bart Vanderbeke -- the art of estimating and planning Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary 1. Study 2. Estimate: • Stick a size number to it • Individually or in team 3. Challenge: • Why did Jim come up with a different number than George? • Surface and eradicate assumptions 4. Decide: • Converge to a consensus on a number • Never average • Never come to a compromise 5. If size was estimated, convert to effort Elements of Size Estimation
- 8. Bart Vanderbeke -- the art of estimating and planning Define the relation between size and effort estimate “Size” convert Effort calibration Effort = function(size) Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Story Points Statistics Goldratt No Shortcuts Mindmap Summary Historical Info detailed case analysis
- 9. Bart Vanderbeke -- the art of estimating and planning More elaborate ‘size’ size complexity How big? How difficult? Feature A Feature B Effort = function(size, complexity) Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 10. Bart Vanderbeke -- the art of estimating and planning Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary T shirt size estimation size complexity How big? How difficult? Effort = function(size, complexity) L S XL M Calibration: 1. Take representative finished project 2. Assign T-shirt size to chunks 3. Calibrate with actual effort T shirt sizing is an example of ‘thinking in analogies’ as described by David Epstein’s in his book “RANGE”
- 11. Bart Vanderbeke -- the art of estimating and planning Scrum estimate Story Points convert person days Select some use cases from the project and estimate in more detail calibration Effort = function(Story Points) Calibration: 1. Take representative use case(s) from project at hand 2. Estimate in most detail add detail until effort-estimation is possible 3. Calibrate with estimated SP Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 12. Bart Vanderbeke -- the art of estimating and planning Why (quasi) Fibonacci? 0 20 40 60 80 100 120 1 2 3 4 5 6 7 8 9 10 Story Points 0 2 4 6 8 10 12 14 1 2 3 4 5 6 7 Story Points Because you would never doubt between consecutive values… Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 13. Bart Vanderbeke -- the art of estimating and planning Estimation and statistics • Estimate three values for each task: • M • E x = µ = 𝑤+4𝑡+𝑏 6 • σ x = (𝑤−𝑏) 6 • Formalizes ‘risk buffers’, ‘uncertainty’, ‘confidence’ https://en.wikipedia.org/wiki/PERT_distribution Value description best Very improbable it will take less than typical When asked only one value…. worst Very improbable it will take longer than PERT distribution (β-distribution) typical shape
- 14. Bart Vanderbeke -- the art of estimating and planning Goldratt • Make your overall schedule for a ‘safe duration’ 90% probability of success • Assign duration with 50% prob. to tasks • Place a checkpoint at 50% • Only grant the extra time when really needed • Parkinson’s law: work expands to fill the allotted time http://www.pmknowledgecenter.com/node/267 impossible possible safe task default project default Only when needed task worst case Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 15. Bart Vanderbeke -- the art of estimating and planning We do not take shortcuts • If the project ‘becomes better by dropping some practice’ then we should always drop it • We always do what we think is necessary and sufficient • We always aim for minimal ‘waste’ in our way of working • Asking for a faster delivery, may challenge us to organize ourselves better • The effect of taking a shortcut: • A shortcut increases the probability to finish earlier, but also to finish later optimal project approach taking shortcuts 𝑃𝑟𝑜𝑏 𝑜𝑓 𝑓𝑖𝑛𝑖𝑠ℎ𝑖𝑛𝑔 𝑎𝑡 𝑡𝑖𝑚𝑒 𝑡 𝑡𝑖𝑚𝑒 𝑡 Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 16. Bart Vanderbeke -- the art of estimating and planning What’s in your toolbox? Estimating fig Estimating txt Size and effort Complexity+Size T- shirt size Scrum Story Points Statistics Goldratt No Shortcuts Mindmap Summary
- 17. Bart Vanderbeke -- the art of estimating and planning Summary ! Estimating using the basic elements is part of your craftsmanship It must not be compromised study,estimate,challenge,decide,3 values
- 18. Bart Vanderbeke -- the art of estimating and planning Overview Method Study estimate values Size/effort challenge decide calibration Expert Judgment individual individual continuous both no expert memory Wideband Delphi individual individual continuous both team team consensus history Scrum Poker team individual (cards) discrete Size (SP) team team consensus selected tasks/UC 𝑐𝑜𝑛𝑠𝑒𝑛𝑠𝑢𝑠 ≠ 𝑐𝑜𝑚𝑝𝑟𝑜𝑚𝑖𝑠𝑒 𝑐𝑜𝑛𝑠𝑒𝑛𝑠𝑢𝑠 = 𝑒𝑣𝑒𝑟𝑦𝑏𝑜𝑑𝑦 𝑎𝑔𝑟𝑒𝑒𝑠 𝑎𝑏𝑜𝑢𝑡 𝑡ℎ𝑒 𝑜𝑝𝑡𝑖𝑚𝑎𝑙 𝑐ℎ𝑜𝑖𝑐𝑒
- 19. Bart Vanderbeke -- the art of estimating and planning • Conclusion is always consensus • Never average estimations • ‘Challenging’ is used to surface assumptions • convert them in facts or kill them • Challenging helps creating a shared context in the team • Use the three-value estimation • Indicates confidence and helps converging • Helps in translation to lead time • No shortcuts Attention points
- 20. PLANOLOGY
- 21. Bart Vanderbeke -- the art of estimating and planning 1. Only the ‘pure coding’ or 2. (Test) design + Coding + unit testing + bug fixing + handling review input • Typically: * 1.6 • Make sure you agree well on what you are estimating What’s in a name? ‘Task’ What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 22. Bart Vanderbeke -- the art of estimating and planning • 𝑡𝑜𝑡𝑎𝑙 𝑒𝑓𝑓𝑜𝑟𝑡 = σ 𝑡𝑎𝑠𝑘𝑖 + σ σ𝑖 2 ∗ 1.6 • Lead time follows from work distribution • Using effective availability and dependencies • adding code freeze • 4 weeks • 𝐿𝑇 > σ 𝑡𝑎𝑠𝑘𝑖+ σ σ𝑖 2 ∗1.6 σ 𝑎𝑣𝑎𝑖𝑙%𝑖 100 + 4𝑤𝑘 ′ >′ 𝑑𝑢𝑒 𝑡𝑜 𝑑𝑒𝑝𝑒𝑛𝑑𝑒𝑛𝑐𝑖𝑒𝑠 From Estimation to Plan What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 23. Bart Vanderbeke -- the art of estimating and planning • Task < week • An ‘atomic’ task must fit in a week • Go into the weekend with a feeling of accomplishment • Sprint • 2…3 weeks • Every two weeks a collective feeling of success Task / Sprint https://www.malotaux.eu/doc.php?id=21 What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 24. Bart Vanderbeke -- the art of estimating and planning What should I define as sprint-goals? creating value for the team members is a fair sprint goal create value for stakeholders What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 25. Bart Vanderbeke -- the art of estimating and planning What if we never make it in the sprints? If you consistently cannot make it 1. Plan less 2. Find the reason why you cannot make it What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 26. Bart Vanderbeke -- the art of estimating and planning What to do first? What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 27. Bart Vanderbeke -- the art of estimating and planning • Production: Avoid intermediate stock • Software: • Avoid results waiting to be used • Software: avoid doing things in parallel just to keep everybody working • Minimize the work in progress • Better one thing finished than everything on its way • Focus of the team • (Kanban/Lean) What should I start? What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 28. Bart Vanderbeke -- the art of estimating and planning Conclusion • Be very conscious what is in (the estimation of) a task • Estimate → plan 𝐿𝑇 > σ 𝑡𝑎𝑠𝑘𝑖+ σ σ𝑖 2 ∗1.6 σ 𝑚𝑒𝑚𝑏𝑒𝑟𝑖∗ 𝑎𝑣𝑎𝑖𝑙%𝑖 100 + 4𝑤𝑘 ′ >′ 𝑑𝑢𝑒 𝑡𝑜 𝑑𝑒𝑝𝑒𝑛𝑑𝑒𝑛𝑐𝑖𝑒𝑠 • Task/Spring: Create your feeling of success • Value can be for any stakeholder • Cannot make it? Step 1: stuff less in sprints • What first? • Beware of starting too many things What’s in a task? Estimate → Plan Accomp. & Success Value Can’t make it? What first? Intermediate stock
- 29. STOP
- 30. DOD FOR DOCS
- 31. Bart Vanderbeke -- the art of estimating and planning DoD and documents