Agile Software Testing in Large

Report
Review:
Agile Software
Testing in
Large-Scale
Project
Talha Majeed
COMP 587
Spring 2011
2
Agenda
 Definitions
 Introduction
 Adopting
XP and diverging from XP
 Guidelines in four Development areas




Test design and activity execution
Working with professional testers
Planning
Defect management
 Summery
 Conclusion
3
Definitions




Agile testing is a software testing practice that
follows the principles of the overall agile
manifesto
In agile testing, testing is not a phase. It is
integrated into Development & Testing
QA is not the last line of defense but involves
at the beginning of the project.
Agile testing focuses on testing iteratively, as
often as stable code base is available, until
quality is achieved from end customer’s
perspective.
4
Definitions

Extreme Programming (XP) is a software development
methodology which is intended to improve software
quality and responsiveness to changing customer
requirements.




Frequent "releases" in short development cycles
which is intended to improve productivity .
XP Approach is that if a little testing can eliminate a
few flaws, a lot of testing can eliminate many more
flaws.
Unit tests determine whether a given feature works as
intended. A programmer writes as many automated
tests as they can think of that might "break" the code;
if all tests run successfully, then the coding is
complete.
Acceptance tests verify that the requirements as
understood by the programmers satisfy the customer's
actual requirements.
5
Introduction

Israel Air Force (IAF) Enterprise information
system



Project was risky



Critical to daily operations & information security
Highly complex and extreme quality
size
Scope (XP-based method)
Risk management


Metrics were developed
Collected & analyzed data
6
Project overview
 Data


collection
Four releases (eight months)
Quantitative data
 Project
team used for project tracking &
decision making

Qualitative data
 Recording
of formal reflection meeting &
debriefings
7
Confirming to XP
 Team
implemented standard XP practices
 Short release



Working software two week iteration
Customer feedback
Goal to achieve measureable testing
benefits
 Short
average time for defect fixes
 Short average defect longevity
8
Confirming to XP

Planning game practice




To plan project iterations and releases
Entire teem met and customer described and
prioritized stories
Goal was to achieve simple design by
refactoring activities
XP’s whole-team and site-together practices

Two measureable results
Defect management overhead was lower
 Fewer false defects

9
Diverging from XP


The project differed from classic XP in three
aspects
First aspect


Second aspect


Team was required to produce detailed
specification in addition to code and test due
to organizational policy.
Project’s accepting testing( user testing) was far
too complex for customer to fully specify
Third aspect

Modified test-driven development to focus on
the continuous creation of automated
acceptance tests rather than unit tests.

Never consider a feature “complete before all
its tests were written and passed.
10
Test design and execution



Each team’s member was responsible for
testing
In a traditional project, "everyone is
responsible for quality,” but in agile project,
everyone actually writes testes.
Advantages



First, It eliminated the team’s reliance's on single
tester
Second, Developers test-awareness increased
Finally, team members wrote specification and
code to write test cases for their work.
11
Test design and execution




Product size = test size
Progress was measured by defining the
project’s product size metrics as the number
of regression test steps ran at each iteration
The above approach was chosen for two
reasons
First, test size is more correlated with
complexity than are lines of code or
specification
12
Test design and execution
 Second,
only features with full regression
testing at each iteration are counted as
delivered product size.

Figure 1 plots the product size metric period of time
13
Test design and execution







Untested work = no work (major shifting to agile
development)
Untested work equals to no work in all channels
and all under conditions.
Written Questionnaire response after two releases
90% team members considered acceptance and
system tests “highly important”
10% ranked as “important”
33% were interested in taking a leading role in
acceptance testing
60% were “interested” in leading system testing.
14
Working with professional
testers
 Why


professional testers?
Add value through more testing
Developers code more features
 Professional
tester two key challenges for
organization


Testing bottlenecks
Coordinating the testing work among
testers and programmers
15
Working with professional
testers
 Easing


bottlenecks
Developer s simply code less, test more
Figure 2. illustrates by comparing the product size metric points
attained by tests that the entire team ran to the team’s tester
alone
16
Working with professional
testers
 Encourage
interaction over isolation
 Initially testers worked alone due to two
reasons


Testers must be independent of programmers
to prevent implementation details from
affecting their test designs.
Specification were up-to-date so testers write
test according to specification
 Testers
were integrated to project team
17
Activity Planning
 Planning




for quality activities involve
Time allocation
Challenges in feature testing
Regression testing
Repair defects
18
Activity Planning
Figure 3. Testing and defect repair
(a) Net hours devoted to running
and maintaining regression tests.
(b) Net hours devoted to fixing defects
19
Activity planning
 Integrate

feature testing and coding
Testing and coding time are usually equal
 Regression
testing: divide and conquer
 Alocate bug-fix time globally


To estimate the time to fix bug is difficult
Reasonably predict the time required to
fixing defects in forthcoming iterations
20
Defect management

Defect management involves two major
challenges



Managing workflow
Selecting and scheduling the defects to fix
Use a team-centered defect-management
approach



Anyone can open defect
Anyone can close a defect, after fixing it
Anyone who finds a defect also assigns it to
someone to be fixed.
21
Defect management

Fix defects as soon as possible



Bug fix time was slightly over an hour
Bug fix requires more time ( a day or more)
should be suspended to prevent bottleneck
and to ensure deadlines are met.
Advantages



Defects require far less time to fix
Working on clean highly stable code base
makes new development faster
Avoids unpleasant customer negotiations over
which defects to solve.
22
Defect management

Figure 3. Average net time to fix a defect per iteration
23
Summery
 Presented
definitions of Agile testing, XP ,
Unit test, Acceptance tests etc.
 How Project adopts/ diverges from XP
 Identified How agile software testing
works on large-scale project
 Showed the graphs of real data from
Israel Air Force enterprise information
system.
 Described the Guidelines in four
Development areas
24
Conclusion



Project's data and analysis are useful both to
practitioners wishing to establish new agile
teams and to research work
Even on large-scale project, the team
achieved full regression testing at each
iteration and developer testing
There is a need of quality data on large-scale
project so, it is highly encouraged for further
investigation on long-term agile projects.

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