Agile Planning And Estimation

28 October 2009

(Agile) planning and estimation

How to plan the flight of a bird?

© Det Norske Veritas AS. All rights reserved.

Wednesday, 28 October 2009

2

Planning, what is it?

Estimation- The art of guessing what the amount of time will be for a certain activity

Planning- The act of scheduling activities over resources and time in order to meet a certain deadline.

“Prediction is very difficult, especially about the future. ”

Niels Bohr



3

The planning onion



4

The ultimate goal?



5

Goals of planning

Reducing Risk

Reducing Uncertainty

Supporting Better Decision Making

Establishing Trust

Conveying Information



6

Estimating

Guessing the complexity and duration of a task/feature



7

Estimating: complexity

Estimating on a relative scale!

We (humans) are good at relative estimating- 1 or 2, 5 or 10?

Example:



8

Estimating: relative estimates

Points are an abstract representation of size, which includes complexity, effort etc.

Scales often used:- Fibonacci scale: 1,1,2,3,5,8,13,21,…- Linear scale: 1,2,3,4,…- T-shirt sizes: S,M,L,XL



9

Estimating: relative points

Points do not have units(!)

Points are not directly related to hours or days

So why use them, if we need to plan on time?

How can we use an abstract concept to derive durations?



10

Points: an example

Dog-points:- The height of a dog from the ground to the shoulder.

Assign dog-points to the following breeds:- Labrador retriever- Terrier- Great Dane (Deense dog)- Poodle- Dachshund- German Sheppard (Duitse herder)- St. Bernard- Bulldog



11

A possible result…

Breed Dog-points

Labrador Retriever 5

Terrier 3

Great Dane 10

Poodle 3

Dachshund 1

German Sheppard 5

Saint Bernard 9

Bulldog 3

What did you choose as a basis, where are your dog-points relative to?



12

Important: Context!

The context of the estimating in points determines the outcome.

What if we chose another dog in the previous example?



13

From points to time

Remember the dogs?

Pick a “known” task as a basis, and extrapolate.

This is in IDEAL-time



14

Now estimate these (in ideal time)



15

So we are done now?

We have a list of features expressed in ideal-time.



16

Two problems remain

Where do we get the complexity points from?- Single source is bad (less context)- Who has the most experience?

- The implementors!

Converting ideal-time to lead-time

Assigning Priority- Business value first!- Technical complexity



17

Getting complexity points

A tool is PLANNING POKER



18

Intermezzo: Agile principles

Collaborate

Learn

Speculate



19

Planning Poker

To determine Estimates- By builders/implementors

Reaching consensus FAST!

Gain relative effort estimations

Speculate

Collaborate



20

ResultTask 1 1

Task 2 3

Task 3 2

Task 4 5

Task 5 2

Task 6 2

Task 7 5

Task 8 13

Task 9 1

Task 10 2

Task 11 2

Task 12 3

Task 13 5

Task 14 8

Task 15 1

Clear,

Consise, tasks

Relative effort

Not: hours/days of work!



21

Planning poker, the mechanics – the cards

People are good at estmating within an order of magnitude.

Remember the ranges? Dog-points?



22

Planning poker --- preparations

We need:

A prioritized list of features or tasks.

An analist or business-person to elaborate on the tasks.



23

Planning poker --- A round of play

Per task:

Each person in the group shows his/her estimation at the same time, don’t think to long about it.

The highest and lowest scores elaborate on their choice (short!)

If needed, a short discussion about the values follows

Repeat the steps above until consensus is reached

Important: don’t give any information about your estimate before showing the card!



24

28 October 2009

Planning

Filling the box…



26

Planning

Several techniques- Planning tasks and dependencies- Planning milestones- Linear planning- Gantt-charts- Time-boxing- Iterative



27

Focus on: time-boxed planning

A Time-box is a fixed period of time. During this time we can work on implementing features (and preferably nothing else..)

A typical time-box is between 2 weeks and 2 months.

Time-boxes are also called iterations



28

Planning with time-boxes Input:

- Desired end-date- Prioritized list of features- “average speed of implementation”

Output:

Planning time-boxes

-20

0

20

40

60

80

100

120

1 2 3 4 5 6 7 8 9 10 11

time box #

Fea

ture

s

Features

Projected end



29

Nr. Of items can grow between time-boxes



30

Speculate

Collaborate

Learn



31

Safeguarding life, property and the environment

www.dnv.com

Technology

Agile Planning And Estimation