Effort Estimation - Chinmay VS - Scrum Bangalore 19th Meetup - March 25, 2017 - at Prowareness

1. EFFORT
ESTIMATION
Write down
the number of
“squares” in the
above image…

2. 5 REASONS WHY ESTIMATES
TEND TO BE WRONG
1. Ambiguous/Incomplete Requirements. No documented
use-cases.
2. Using Assumptions/Gut-feeling. Instead of facts.
3. Large-Scale. No breakdown structure = Omitted activities.
4. Single-Point Estimates. Average ≠ Conditional.
5. Bad work processes Bad design, code  Bugs 
Rework/Firefighting.

3. THE 6TH SECRET REASON WHY
ESTIMATES ARE WRONG
OFF THE CUFF
ESTIMATES !
Q. Can you get this done by
Friday?
Answer: Looks do-able. I will try.
What is the right question? What is the right way to
answer it?

4. CONE OF UNCERTAINTY

5. ¯_(ツ
)_/¯
NOT KNOWING THE
ANSWER IS OKAY

6. 1. Ambiguous/Incomplete Requirements. No documented
use-cases.
2. Using Assumptions/Gut-feeling. Instead of facts.
3. Large-Scale. No breakdown structure = Omitted activities.
4. Single-Point Estimates. Average ≠ Conditional.
5. Bad work processes Bad design, code  Bugs 
Rework/Firefighting.
5 REASONS
THE 6TH SECRET REASON WHY
ESTIMATES ARE WRONGQ. Can you get this done by
Friday?
Answer: Looks do-able. I will try.

7. RIGHT QUESTION? / RIGHT
WAY TO ANSWER IT?
1. Ambiguous/Incomplete Requirements. No documented
use-cases.
2. Using Assumptions/Gut-feeling. Instead of facts.
3. Large-Scale. No breakdown structure = Omitted activities.
4. Single-Point Estimates. Average ≠ Conditional.
5. Bad work processes Bad design, code  Bugs 
Rework/Firefighting.
Q. Can you get this done by
Friday?
Answer: Looks do-able. I will try.

8. ESTIMATES
THE USUAL
SUSPECTS
Reference: Software
Estimation
Demystifying the Black Art
– Steve McConnell

9. PRECISION = UNINTENDED
CONFIDENCE.It is10:30 am. You are on your way to meet a
friend…
You: “Will see you at the mall by 11 o’clock.”
Sounds like will be there sometime before 11:05
VS.
You: “Will meet you at the mall at 10:58am.”
Sounds like will be there sometime before 10:59
The 2nd estimate was simply based on
an ETA of 28mins shown by the navigation app at
10:30.

10. INTERESTING BITS FROM
AROUND THE WORLD...
Calculating Functions Points - A practical example…
 stackoverflow.com/q/34473698/319204
“Function Points? Valuable, but too much effort to get right.” - Mike Cohn
(Scrum Alliance)
 stackoverflow.com/a/153458/319204
12 tips to better estimates
 stackoverflow.com/a/35571856/319204
PMBOK – 5th Edition
 A Guide to the Project Management Body of Knowledge – 5e