want better estimation ?
DESCRIPTION
Presentation made at the PMDays Bucharest 2012 from the PMI Romania ChapterTRANSCRIPT
Want a better estimate ?Alexandre Cuva
Coach Agile, CSM, CSPO, LTM3 HSPTPPMDay Bucharest - 2012
Alexandre Cuva
Email : [email protected]
Twitter: @cuvaalex
Blog: http://agile-alexcuva.blogspot.com/
Phone: +41 78 715 8309
Organizational Coaching (Management 3.0, Scrum)
Team Coaching (Scrum, XP, Kanban)
Technical Coaching (TDD, BDD, C#, Java, Groovy)
Agile Training (Management 3.0, Agile, Scrum, XP)
Observation
The complexity is growing fast
Observation
The current standard management system, does not provide satisfaction to all.
My Actual Mission
Help companies to make this sentence True for them
“Organizations can become learning networks of individuals creating value, and the role of leaders should include the stewardship of the living rather than the management of the machine.”
http://www.stoosnetwork.org
How to have an Accurate Estimation ?
Common Scenario
Didn’t hear me I say it should be done in 3 month !!!
How long do you think this project will take ? we need to finish in 3 month.
I think in 6 month we will be done
Problem of estimation
From this picture
Estimate the size of my submarine ?
3 points estimation
The 3 point estimate belongs to the time management knowledge area. It can also be used during Cost Estimation.
A three point estimate is a better estimate, compared to a single point estimate. Single point estimate simply gives you a single number scenario
1. Take the worst scenario
2. Take the best scenario
3. Take the median
E = (O+M+L)/3
Things that influence Estimates
Project Size
Type of Software
Personnel Factors
Programming LanguagesComplexity
Constraints
Turnover
Experience
Culture
Tools
Team Cohesion
Management
…
Are estimate important ?
EstimationDefining Iteration
Scheduling
Prioritization
Break Work
What is estimate?
Prediction Target Agreement
Estimate Target Commitment
Source : Want a better estimates ? Stop Estimating by Joel Semeniuk
Estimation Challenges
Provides an 95% Confident estimation for:How old I am ?How many bugs will have on the next project ?What is the distance between the earth and the moon ?What is the % surface of water on Earth ?
Question: What make you are confident at 95%
Important Laws of Nature
Parkinson’s LawThe amount of time which one has to perform a task is the amount of time it will take to complete the task.
The Student SyndromeStart as late as possible
Exponential Error AggregationThe more detailed – the further from truth you will be
Source : Want a better estimates ? Stop Estimating by Joel Semeniuk
ESTIMATION LAW5 law to Ponder from Joel Semeniuk
Source : Want a better estimates ? Stop Estimating by Joel Semeniuk
Estimate Law #1
Don’t estimate if you can measure
Estimate Law #2
Estimate in a way human are good at !
Compare instead estimate unit
Estimate Law #3
Measure things that are Measurable Eg Start-Finish Time
versus Actual versus Planned Effort
Estimate Law #4
Vision
Roadmap
Release
Iteration
Day
To mitigate the risk of incorrect effort estimations we reduce the precision of our estimates according to how much we know about what we’re estimating.
This in turn helps us to be more accurate.
Cone of Uncertainty
Estimation Law #5
Size
Duration
Effort
Use the different Metrics for different Estimates
GOOD PRACTICE TO START
Simple Practices that Work
Use Sizing for Requirements
Measure Velocity
Decompose into Task Just in Time in Hours
Calibrate and Recalibrate
Use cycle Time to Predict Expected Duration
Use Sizing for RequirementExample : Ski trail difficulty
Numeric Values½, 1, 2, 3, 5, 8, 13, 20, 40, 50, 100
Green Trail : ½, 1, 2, 3 (16)Blue Trail : 5, 8 (8)Red Trail : 13, 20 (8)Black Trail : 50, 100 (8)
Business Solutions
Measure Velocity
The amount of product backlog that a team can handle in one single sprint
Quantified in story points
Story point is an arbitrary measure to quantify the required effort to finish an user story. Namely, how hard the story is. Loosely based on Fibonacci series.
Size Stories
Story should fit in one Iteration
Story too complex should be split on multiple simple one
Fixed Cycle Time
Measure the time to resolve
Remember Law #1 : Measure instead guessing
Summary
Estimation Law1. Don’t estimate if you can measure2. Compare instead estimate unit3. Measure things that are Measurable 4. Reduce the precision of our estimates according to how much we know5. Use the different Metrics for different Estimates
Good Practices• Sizing for requirement• Hours for small task• Velocity• Size Story• Fixed cycle time
Resources
Alexandre Cuva
Email : [email protected]
Twitter: @cuvaalex
Blog: http://agile-alexcuva.blogspot.com/
Phone: +41 78 715 8309
Organizational Coaching (Management 3.0, Scrum)
Team Coaching (Scrum, XP, Kanban)
Technical Coaching (TDD, BDD, C#, Java, Groovy)
Agile Training (Management 3.0, Agile, Scrum, XP)