To Estimate or Not to Estimate, Is that the Question? LeanAgileUS 2017
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The document discusses the debate around estimating work in software development projects. It presents different perspectives on estimating, from never estimating to always estimating. It acknowledges that many factors contribute to variation in how long work takes, beyond just the estimated effort. Approaches like focusing on reducing waste, making work visible, and creating probabilistic forecasts based on delivery data can help address variation better than relying solely on upfront estimates. The question is reframed from whether to estimate or not, to what can be done to maximize value and reduce risk in planning and delivery.
To Estimate or Not to Estimate, Is that the Question? LeanAgileUS 2017
- 1. To Estimate or Not to Estimate, Is that the Question? #leanagileUS @mattphilipLeanAgileUS Conference, 27 Feb 2017
- 2. Hofstadter’s Law “It always takes longer than you expect, even when you take into account Hofstadter’s Law.” #leanagileUS @mattphilip
- 3. Parkinson’s Law “Work expands so as to fill the time available for its completion." #leanagileUS @mattphilip
- 4. ”Poor Estimation Skills” #leanagileUS @mattphilip
- 5. The Spectrum of Estimating Never Estimate Anything Always Estimate Everything Question purpose of estimating Include all sources of variation Focus on characterizing work Probabilistic forecast Use delivery data Less effort spent Estimation culture Consider effort only Deterministic forecast Use intuition Heavy effort involved Tasks in hours #leanagileUS @mattphilip
- 6. What NoEstimates is not saying • You are evil if you estimate • All estimates are totally useless • Stop doing your successful estimating practice • Stop having the conversations to understand/analyze/break down work • Work items must be the same size • You must place your full faith and confidence in Monte Carlo forecasts #leanagileUS @mattphilip
- 7. What NoEstimates is saying • Know why you are estimating • Discover for yourself how good you are at estimating (measure) • Keep doing the things that help you understand the work • Upfront estimates need to be held loosely #leanagileUS @mattphilip
- 8. NoEstimates, Manifesto Style … We have come to value: Probabilistic over Deterministic Delivery time over Development time MVP scope over Full scope Data over Intuition* Reducing sources of variation over Improving estimating That is, while there is value in the items on the right, we value the items on the left more. *Neil Killick uses “empiricism over guesswork” #leanagileUS @mattphilip
- 9. Sources of Variation #leanagileUS @mattphilip
- 10. Do You Assume Correlation? Is the initial sizing a good predictor for when you can get your stuff? In our case, the surprising truth was ”no.” -- Mattias Skarin, Real-World Kanban #leanagileUS @mattphilip
- 11. What’s Going On? Low process efficiency (typically 5-15% in software delivery) means that even if we nailed the effort estimates … we would be accurately predicting 5-15% of elapsed delivery time! -- Troy Magennis #leanagileUS @mattphilip
- 12. Other Sources of Variation Often system factors account for more of the elapsed delivery time than different story sizes. -- Troy Magennis #leanagileUS @mattphilip
- 13. Sources of Variation #leanagileUS @mattphilip How many can you name?
- 14. Sources of Variation #leanagileUS @mattphilip • WIP • Technology/domain/product • Team composition • User, client and client representative • Multitasking/focus factor • Market and competitors • System dependencies • Team dependencies • Specialization • Waiting for availability • Rework • Steps/handoffs (50%*50%*50%...) • Stages in team development (Tuckman) • Selection policy • Essential complication (How hard a problem is on its own) • Accidental complication (“How much we suck at our jobs” -Rainsberger)
- 15. First, Know Where You Are #leanagileUS @mattphilip
- 16. Keogh’s “Scale of Ignorance” 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. #leanagileUS @mattphilip
- 17. What Can You Do About Variation? #leanagileUS @mattphilip How many remedies can you name?
- 18. What You Can Do About Variation • Lower WIP • ConWIP/System WIP • Five Focusing Steps • Blocker clustering • Reduce workflow stages • Explicit policies • Cost of Delay scheduling, sequencing and selection #leanagileUS @mattphilip Lean-Kanban
- 19. What You Can Do About Variation • “Agile 101” (simple, decoupled design; thin vertical slices; pairing) • Identify/make visible/measure dependencies • Collaborate/Share work (Dimitar Bakardzhiev) • Spike and stabilize (Dan North) • Reduce accidental complexity (Liz Keogh) #leanagileUS @mattphilip Team Why?
- 21. NoEstimates and the Business • Determine what actions would be different based on the estimate • Customer-based fitness criteria • Budgeting: Team run rate • Focus conversation on value, not cost • MVP and product ownership • Create probabilistic forecast ASAP (as soon as you have data) – together! • Service-Delivery Reviews • Teams: Keep teams together, dedicated (reduces context-switching, Tuckman stages) #leanagileUS @mattphilip
- 22. To Estimate or Not to Estimate? Never Estimate Anything Always Estimate Everything Question purpose of estimating Include all sources of variation Focus on characterizing work Probabilistic forecast Use delivery data Less effort spent Estimation culture Consider effort only Deterministic forecast Use intuition Heavy effort involved Tasks in hours #leanagileUS @mattphilip A better question: What can you do to maximize value and reduce risk in planning and delivery?
- 24. • noestimatesbook.com (Vasco Duarte) • focusedobjective.com (Troy Magennis) • actionableagile.com (Dan Vacanti) • infoq.com/articles/noestimates-monte-carlo (Dimitar Bakardzhiev) • priceonomics.com/why-are-projects-always- behind-schedule/ • scrumandkanban.co.uk/estimation-meets- cynefin/ • ronjeffries.com • lizkeogh.com • neilkillick.com • zuill.us • mattphilip.wordpress.com/tag/noestimates References and More Info #leanagileUS @mattphilip