This document discusses alternatives to agile estimation practices. It recommends focusing on real constraints rather than estimates, keeping development teams stable, using extreme programming practices, delivering working software frequently, and iterating work. The document also advocates slicing stories into smaller pieces to limit work in progress, focusing on delivering value over estimating costs, and measuring cycle times to identify bottlenecks.

1. ALTERNATIVES
to AGILE
ESTIMATION
NEIL KILLICK
neilkillick.com
neil_killick #NoEstimates

3. AND WHEN
WHAT WILL I GET

4. ESTIMATING OR GUESSING?

5. MAKING PREDICTIONS <>
PREDICTABILITY

6. USE *REAL* CONSTRAINTS

7. KEEP TEAMS TOGETHER

8. USE XP PRACTICES
● Continuous
integration
● TDD/BDD
● Pair programming
● Clean code

9. DELIVER EARLY & OFTEN

10. FOCUS ON FLOW

11. ITERATE *AND* INCREMENT

12. BACKLOG = OPTIONS
● You will NOT build the whole backlog
● Knowing this is empowering

13. DOES SIZE MATTER?
8
Smaller, cheaper (?)
awesome feature
Awesome
feature
13

14. FOCUS ON VALUE, NOT COST
● Iterative Funding
● Emergent Value

15. USE A SLICING HEURISTIC
● Explicit policy for
breaking up work,
e.g. "A story must
have only one
acceptance test"
● Slice stories JIT (e.g. in Sprint Planning)
● Can add to "Definition of Ready"

16. WHY IS THIS BETTER THAN
ESTIMATING?
● Explicitly promotes the good practice of
splitting work to be done
● Avoids cognitive biases
● Easy to measure effectiveness (e.g. mean &
median cycle time within x%)

17. LITTLE'S LAW IS KEY
CYCLE TIME =
WIP /
THROUGHPUT

18. ● Size of premises
● No. & size of ovens
CONSTRAINTS REDUCE
VARIABILITY AND LIMIT WIP
● No. of chefs & drivers
● Delivery radius

19. ● Avg. wait time (hours) =
Number of orders in progress (WIP)
/ Avg. orders completed in an hour (throughput)
● Assume throughput is 50
● Using Little's Law, 0.5 = x / 50
● x = 25
● We should only take on 25
orders at a time
MAX. 30 MINUTE
WAIT FOR CUSTOMERS

20. WHAT IF WE TAKE
ON MORE ORDERS?

21. TAKING ON MORE ORDERS
MAY INCREASE WAIT TIME
● Now our WIP is 30 orders
● x = 30 / 50
● x = 0.6 hours = 36 minutes
● If we can actually deliver
60 pizzas per hour, wait
time will not increase

22. LIMIT WIP, LOW CYCLE TIME
WIP
limits

23. CYCLE TIME DISTRIBUTION
● Measure actual
cycle time to
identify outliers
● Measure mean
and median
averages

24. EASY TO MEASURE & SHOW
● Update cycle
time at daily
standup
● Use coloured
dots to represent
number of days
An awesome feature
that's taken 4 days

25. IN SUMMARY
● Real constraints breed creativity
● Keep teams together
● Use XP practices for technical excellence
● Put the "iterate" back into iterations!

26. IN SUMMARY
● Treat the backlog as options
● Focus on value, not cost
● Slice work using a heuristic
● Limit WIP and measure cycle times

27. Thank you
NEIL KILLICK
neilkillick.com
neil_killick #NoEstimates