estimating story points in agile - magic approach

Estimating Story Points

in Agile - Approach

1 3

8 5

Bollapragada. Venkata. Marraju

[email protected]

[email protected] https://in.linkedin.com/in/marraju

mailto:[email protected]


There is a debate around story point estimation techniques and growing

demand for guidelines & standardization.

Fixed Story pointing

1 Story Point = 10 Person Hours

1 Story Point = 1 Person Working Day

Expert Influence

Guestimate

Fallout:

In Accurate Estimates

No reflection of Improved Velocity. Hours based assignment of points

will not reflect the improved productivity

Current Estimation Practices

Marraju Bollapragada

Project Triangle


Velocity = Story Points (Scope) achieved per Sprint Capacity (Resources x Time)

Agile Velocity Triangle


Work vs Velocity


WORK VELOCITY

WORK is a defined scope irrespective of Resources & Time

‘VELOCITY’ is the rate at which the ‘RESOURCES’ completes ‘WORK’ within a given ‘TIME’ period.

Work is a measure of the business value earned or expected to earn

Velocity is the measure of a performance or productivity after execution

Work is estimated at planning stage using below techniques: • WBS (Vertical Slicing) • Relativity • Business Value

Velocity is calculated after execution based on the effort spent to complete a defined scope of work

• Work Estimation • Effort Estimation • Cost Estimation are 3 different terms & types of estimations

• Velocity is a Trend

• Burndown is a Log

Velocity = Story Points (Scope) achieved per Sprint Capacity (Resources x Time)

Agile Velocity Triangle

• Laying Slab of 1000 Sqft • Laying Road 40 ft x 5km • Producing 100 Laptops • Serving Food for 100

People • Developing an App for

Online Catalogue -???

• Laying Concrete Slab of 1000 Sqft –10$ /Sqft • Laying BT Road 40 ft x 5km – 5k$ /Km • Producing 100 Laptops- 500$ /Laptop • Serving Food for 100 People – 5$ /Plate • Delivering an App for Online Catalogue – Fixed

Cost or Earned Value basis

• Laying Concrete Slab of 1000 Sqft – 20 Days • Laying BT Road 40 ft x 5km – 25 Days • Producing 100 Laptops- 4 Days • Serving Food for 100 People – 5 Hours • Developing an App for Online Catalogue – Time Boxed/Effort based


Estimation in Agile

SCOPE

• Story Pointing -1,3,5,8,13

• WBS > Relativity & Complexity

• Planning phase

TIME

• Capacity Planning - Person Hours

• WBS > Resource & Scheduling

• Planning & Execution phase

COST

• Effort in Dollars - $$

• Fixed Cost /Time & Material Cost

• Budget & Billing phase

Work Estimation (Scope in Business Value/

Story Points)

Effort Estimation ( Work in Person Hours)

Cost Estimation (Effort in $$)


Estimating with MAGIC Approach – Measure, Analyze, Improve and Control without ‘Guess’ work Measure & Analyze using ‘Story Point Matrix’ based on

Functional & Technical Analysis

Improve & Control using Statistical Data Modeling based on Empirical Data extracted from agile project management tool

Proposed Solution- Approach


Story Pointing - Technique

Create the Task Template for

Analysis

Design

Development

Testing

Packaging


Story Point Matrix Empirical Data Model

Based on Expert Judgment Based on Empirical Data

Create Work Break Down Structure for the Scope • Epics to Sub Epics

• Sub Epics to Stories • Slicing Stories

• Stories to Tasks

Identify and analyze the • Functional Logic • Technical Implementation • Testing, Doc and Packaging requirements

Compare with relatively similar type of story executed previously

Identify the • Resources • Skill/Expertise • Technology • Tools • Complexity

• Identify the elements that are added/updated/upgrade across the layers

• Aggregate the count by functional & technical task type and assign the complexity factor

• Map the cumulative functional & technical points of the story to the Range in ‘Story Point Reference Table’ to size with appropriate Story Point

Look at the Empirical Data • Draw the Frequency Histogram (with + 3 SD) for

completed Story Points vs Actual Hours • Point the Story based on the estimated hours that

fall with in the +1SD of the mean in the Histogram

• Resources and Hours not considered

• Based on only Functional and Technical analysis

• Resources and Hours are considered

• Version Report (in Jira) which projects expected

completion date of project is based on empirical

data for the completed stories and hours spent

which is nothing but velocity.

: Story Point Matrix

Step#1 : Create ‘Story Point Reference Table’

Select the previously completed stories of different story point sizes, at least 3 stories for each

story point size

Create WBS for each of those stories by vertical slicing (as shown in next slide)

Identify the number (count) of elements/ interfaces/objects/components/TCs created/ updated/

upgraded for each of those tasks

Aggregate the count by functional & technical task types and assign the complexity factor

Take the total of cumulative functional & technical points

Repeat the above step for all the selected stories

Prepare the ‘Story Point Reference Table’ by defining the ranges for cumulative functional &

technical points by Story Points

Step#2: New Story#

Now create a similar story point matrix for new story and map the cumulative functional &

technical points of the story to the Range in ‘Story Point Reference Table’ to size with

appropriate Story Point


: Story Point Matrix

Ex: Story Point Reference Table

Cum Func &

Tech Points

Range

Story

Point

0-10 1sp

10-30 2sp

30-50 3sp

50-80 5sp

80-130 8sp

>130 13sp

Story# Work Breakdown Structure (WBS)

Story#1

Functional & Technical Tasks

New Update Upgrade/

Execute Complexity Factor Cumulative

(count) (count) (count) cf Func &Tech Points

a b c 0.1/0.2/0.3/0.5/0.8/1 (D=a+b+c) x cf

User Interface

(No. of Elements)

Business Layer

(No. of Classes, Methods,

Functions, etc..,)

Database Layer

(No. of Database Objects)

Integration - API/WebServices

(No. of APIs/Services)

Environment Setup

(No. of Products Installed)

Manual Testing

(No. of Test Cases)

Automation Testing

(No. of Test Scripts)

Packaging/CM

Documentation

(No. of Topics)

Total of Cumulative

Story Points (from Reference

Table)


Step#1: Create Frequency Histogram:

Extract the data from the agile project management tool for the completed stories after the completion of project

Group the stories by story point size

Prepare the frequency histograms

by Story Point (1,2,3,5,8)

by Release version (9x, 10x, etc.,)

with Hours on X- axis and Story Count (No. of Stories) on Y-axis

Take the Bin Range for Hours with +3 SD form the Average (Mean)

Mark the Mean and Hours at which the frequency peaks in the histogram

– Average No. of Hours taken to complete by

maximum Number of Stories

: Empirical Data Model

Standard Deviation

Bin/Range in Hours +3 SD

Frequency of 3 SP Stories # v10.x

-3SD -50.508989 0

-2SD -25.437739 0

-1SD -0.3664885 0

Average (Mean) 24.704762 134

+1SD 49.776012 53

+2SD 74.847263 12

0 0 0

134

53

12

-20

0

20

40

60

80

100

120

140

160

-75 -50 -25 0 25 50 75 100

No

of

Co

mp

lete

d S

tori

es

Actual Hours Spent to Complete Stories

Frequency of 3 SP Stories # v10.x

Frequency of 3 Story Point Stories…


Step#2: Estimate New Story# based on Frequency Histogram:

List the Tasks of the new Story#, and Identify

the Resources and Hours required for

the delivery of the Story# as shown in the

‘Task Table’

Now map the ‘total estimated hours’ of the new

story# from the ‘Task Table’ to the matching

frequency histogram into which it falls within

the range of +1SD of the mean

Take that as a Story Point for the new Story#.


Task Table for Story#

Task Resources Hours

Analysis Task

Design Task

Development Task

Database Task

Testing Task

CM Task

Documentation Task

Total Estimated Hours

Story Point (from

Empirical Data in Step#1)



Example:

Extracted the data from agile project management tool

for a solution suite based on below criteria and plotted

the ‘Frequency Histogram’:

Issue Type – Stories

Status – Completed

Release Version : 9.x & 10.x

Frequency Histogram plotted for – 1, 2, 3 & 5 Story point

stories


0 0

22

119

61

10

-20

0

20

40

60

80

100

120

140

-100 -75 -50 -25 0 25 50 75 100 125

No

of

Sto

rie

s

Hours

Frequency for 2 SP # 9.x

Frequency for 2 SP # 8.1

0 0 0

177

68

15

-50

0

50

100

150

200

-75 -50 -25 0 25 50 75 100

No

. of

Sto

rie

s

Hours



0 0 0

94

36

17

-20

0

20

40

60

80

100

-20 -15 -10 -5 0 5 10 15 20 25

No

of

Sto

rie

s

Hours



0 0 0

67

34

7

-20

0

20

40

60

80

-75 -50 -25 0 25 50 75 100

No

of

Sto

rie

s

Hours




Empirical Data Model - Histogram for 1 & 2 story point

0 0

30

141

69

18

-20

0

20

40

60

80

100

120

140

160

-200 -100 0 100 200 300

No

of

Sto

rie

s

Hours

Frequency for SP 5 # 9.x

Frequency for SP 5 # 8.1

0 0 0

257

103

34

-50

0

50

100

150

200

250

300

-150 -125 -100 -75 -50 -25 0 25 50 75 100 125 150 175 200

No

of

Sto

rie

s

Hours



0 0 0

134

53

12

-20

0

20

40

60

80

100

120

140

160

-75 -50 -25 0 25 50 75 100

No

of

Sto

rie

s

Hours



0 0

30

90

56

14

-50

0

50

100

-100 -50 0 50 100 150

No

of

Sto

rie

s

Hours

Frequency for SP 5 # 10.x

Frequency for SP 5 # 9.0


Empirical Data Model - Histogram for 3 & 5 story point



Design

Development

Testing

Packaging

Story Point

STORY POINT MATRIX EMPIRICAL DATA MODEL

Range of Cum Func & Tech Points taken from Story Point Reference Table

Range of Actual Hours Spent to Complete the Stories taken from Empirical Data Model

1sp 0-10 10-25

2sp 10-30 25 - 50

3sp 30-50 50-75

5sp 50-80 75-100

8sp 80-130

13sp >130

Matrix - Example



Design

Development

Testing

Packaging

Technique Recommendation Suitability Story Point Matrix Estimation Empirical Data Model Estimation

New Product Yes No

New Team Yes No

New Functionality Yes No

New Technology/POC Yes No

Existing Product Yes Yes

Same Team Yes Yes

Same Code base Yes Yes

Same Technology Yes Yes

PMG/FA/BA Availability Must Depends

Definition of Ready Required Depends

Definition of Done Required Required

Finale Recommendation

Use the Story Point Matrix for regular Story Point Estimation by

measuring and analyzing the functional and technical tasks of

the story

Use the Empirical Data Model for retrospection/reviewing the team’s

performance on story sizing after the project completion and use as a

reference to improve and control


Templates

Templates

https://docs.google.com/spreadsheets/d/1p5t3HH_FCNTM9dxlot

t8nZZbOxVSSrx8PY0v0D-c0PQ/edit?usp=sharing

Template for Story Point Matrix


t8nZZbOxVSSrx8PY0v0D-c0PQ/edit#gid=1590278669

Template for Empirical Data Model


t8nZZbOxVSSrx8PY0v0D-c0PQ/edit#gid=188166086

https://docs.google.com/spreadsheets/d/1p5t3HH_FCNTM9dxlott8nZZbOxVSSrx8PY0v0D-c0PQ/edit?usp=sharing




https://docs.google.com/spreadsheets/d/1p5t3HH_FCNTM9dxlott8nZZbOxVSSrx8PY0v0D-c0PQ/edit#gid=1590278669












References from Mike Cohn’s (Mountain Goat Software) Blog: Template for Story Points Are Still About Effort

http://www.mountaingoatsoftware.com/blog/story-points-are-still-about-effort

Seeing How Well a Team’s Story Points Align from One to Eight

http://www.mountaingoatsoftware.com/blog/seeing-how-well-a-teams-story-points-align-from-one-to-eight

How Do Story Points Relate to Hours?

http://www.mountaingoatsoftware.com/blog/how-do-story-points-relate-to-hours

References

























































Than‘Q&A’

Bollapragada. Venkata. Marraju

[email protected]

[email protected] https://in.linkedin.com/in/marraju



estimating story points in agile - magic approach

Software

story points scope

execution work

fixed story

resources time velocity

agile scope story pointing

log velocity

guess work measure

scope epics