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 Error Aggregation

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