Lies, Damn Lies…. and Estimates

Bhavin KamaniIndependent Agile Coach

Are Estimates Illusion?

It all starts as a SIMPLE problem

Reality

Estimation Challenges

Provide a 90% Confident Estimate

forHow old am I?

What is the size of the largest sea turtle

ever discovered?

How many bugs will you have in your next

project?

What is the total volume of all the lakes of

the world?

Important Laws of Nature

Parkinson’s Law

If you give a person 5 days to deliver a task that could be

delivered in 4, the person will find something to do with that

extra day (air fills the container)The Student Syndrome

If given too much time, people naturally procrastinate until

late in the project, at which point they rush to complete the

work, and likely won’t finish on timeExponential Aggregation Error

The finer grained estimates you have, the more error you are

introducing into the aggregate (the more detailed – the

further from the truth you will be)

Man Hours

Story Points

Cycle Time

Cumulative Flow Diagram

Guidelines

#1 Don’t Estimate if you can measure

#2 Breakup stories over granular estimation

#3 Create a strong definition of ready and done