A straightforward way to forecast project progress in an agile environment.

1. Neil Killick, Lead Agile Coach
neilkillick.com neil2killick@gmail.com @neil_killick
A simple model for
Estimating without guessing
Copyright Neil Killick, 2015

2. In complex environments, what will happen
is unknown.
Only what has happened may be used for
forward-looking decision-making.
-- The Scrum Guide

3. Backlog Doing Done
How long will this card take?
Ready
?

4. Backlog Doing Done
Days
Stories
1
2
3
4
5 5.3%
5.3%
26.3%
How long will this card take?
26.3%
36.8%
Ready
100.0%
94.7%
89.4%
63.1%
36.8%
?

5. Milestone 1
Backlog
Doing Done
How about this card?
Ready
?

6. Measure throughput and standard
deviation (variance).
The variance empirically represents
different story sizes.
Throughput: 4, 4, 5, 4, 5, 4, 4
Avg throughput = 4.3 Std dev = 0.5
Throughput: 4, 8, 2, 3, 5, 4, 4
Avg throughput = 4.3 Std dev = 1.9

7. Average throughput + standard deviation
= Optimistic throughput forecast
Average throughput - standard deviation
= Pessimistic throughput forecast

8. We can now answer the standard estimate
questions using empirical data.

9. When will milestone 1 be done?
Most likely mid-late
December

10. What will be done by Jan 1st?
Most likely,
milestone 1 and
some of milestone 2

11. When will milestone 2 be done?
Most likely in first
half of January

12. Will milestone 2 be done by Jan 1st?
(aka “Are we on track?”)
Highly unlikely
(optimistic forecast for
current scope falls after date)

13. Will milestone 2 be done by Jan 4th?
Maybe
(optimistic says yes, neutral
says no)

14. Will milestone 2 be done by Jan 7th?
Maybe
(neutral says yes,
pessimistic says no)

15. Will milestone 2 be done by Jan 15th?
Highly likely
(pessimistic forecast for
current scope falls before
date)

16. ❏ Use empirical data
❏ Measure throughput and incorporate variance
using standard deviation
❏ Avoid surprises by using ranges and shades of
confidence
In summary

17. Neil Killick, Lead Agile Coach
neilkillick.com neil2killick@gmail.com @neil_killick
Copyright Neil Killick, 2015