Testing: Chances and Challenges in an agile World

Testing im Wandel
Neue Herausforderungen
und Chancen in einer agilen
Welt
Jonas Bandi
Software Architect
TechTalk
jonas.bandi@techtalk.ch
blog.jonasbandi.net
www.techtalk.ch twitter.com/jbandi
Thursday, November 5, 2009

"We're still
ﬁguring this
stuff out.
All of us."
- Jay Fields

Thoughts on developer Testing:
http://blog.jayfields.com/2009/02/thoughts-on-
developer-testing.html


My point of view
• Software Architect at TechTalk
• TechTalk is a software development
and consulting company with ~60
people located in Vienna, Budapest
and Zürich.
• The main business is building
custom IT solutions for clients in
Austria and Switzerland.
• Projects of TechTalk involve
development efforts of up to
several thousand person days and
team sizes of up to ten persons.


Once upon a
time...
... in the golden
Age of the
Waterfall.


... and they lived happily ever after!


Welcome to the real world!

... the golden age is over!


What did really change?
49% 24%
23% 44%

32%
28% sucessful
challenged
failed
2000 2008
Project success
Chaos Report, Standish Group

What is the problem?

There are many!

Focus: Requirements

What deﬁnes success?

Software development is about
delivering business value!

What is being used?
19% 16% Never
Seldom
13% Occasionally
45% 7% Often
Always

CHAOS Report 2000, Standish Group


Providing Business Value?
• Only 20% of all delivered features are
actually used?
• Something is wrong!
• We can proﬁt tremendously when we
improve in requirements gathering and in
transporting them successfully to the
implementation


Where Errors are introduced

Requirements
27% Design
56% Code
7% Other
10%

Source: James Martin, An Information Systems Manifesto

Fighting Errors?

• Traditional Developer Testing focuses on
code and maybe design
• Testing requirements is hardly ever a topic
• We can proﬁt tremendously when we
improve in requirements gathering.


Detailgrad

Vision Verständnisgrenze
Actor/Stakeholder

Lastenheft

Pflichtenheft

Designdokument

Kein Feedback von
Stakeholdern möglich! Code

Manual Test Automated
„Usage“ Test
Zeit

Waterfall Project

Costs to ﬁx defects rise
exponentially over time

The longer a
defect stays in the
development
process, the more
expensive it is to
ﬁx


Agile to the rescue!

Detailgrad

Verständnisgrenze
Actor/Stakeholder
Actor/
Business
Vision Stakeholder
Projektstart

goals
goals

Product
Epics Stories
Backlog

Sprint Planning Preparation
Sprint Acceptance
Sprint 1-n

Stories
Sprint Planning Backlog Criteria

Sprint Implementation Acceptance
Kurze Feedbackzyklen Test
Definition
mit Stakeholdern Code
Manual Test/ Automated
Demo Test
Zeit

Iterative Project

The beneﬁts
• Constant feedback and priorization
by the Stakeholder 19%16%
• Build those features that are 45% 7%
13%
needed and useful
• Features have a much shorter 27%
through-put time
7%
• Allows validation of requirements 56% 10%


Wait...
... isn’t this
presentation
supposed to be
about testing?


"I believe that the hardest part of software
projects, the most common source of
project failure, is communication with the
customers and users of that software."
- Martin Fowler, DSL Book


It is all about communication!


Verständnisgrenze
Actor/Stakeholder
Actor/
Business
Vision Stakeholder
Projektstart

goals
goals

Product
Epics Stories
Backlog

Sprint Planning Preparation
Sprint Acceptance
Sprint 1-n

Stories
Sprint Planning Backlog Criteria

Sprint Implementation Acceptance
Kurze Feedbackzyklen Test
„Vertrauenswürdige Definition
mit Stakeholdern Code
Kommunikation“
Manual Test/ Automated
Demo Test
Zeit

Enable communication

How?


Catch bugs in requirements!

Cost

RE
Analysis & Design
Requirements Engineering
Implementation
Testing

Deployment Analysis & Design

Implementation

Time Testing
RE
Analysis & Design
Implementation Deployment
Testing

Deployment

Now...
... ﬁnally testing!


Requirements == Tests
“As formality increases, tests and
requirements become indistinguishable. At the
limit, tests and requirements are equivalent.”
- Equivalence hypothesis, Robert C. Martin

• Traditionally this is not recognized because RE and
Testing are set up as different disciplines
• But they are about the same: how the system is used
• Wouldn’t it make sense to leverage some synergies?

Ideally Tests ...
• … describe what the system should do
• … are business readable
• … establish a common vocabulary
• … capture a shared set of examples
• … enable communication
• … are bound to the implementation
• … are executable
... express shared understanding


Building a shared understanding
- Scripts
- Test Data
Mapping
- Acceptance
Criteria
Business
Business
- Speciﬁcation - Scripts
Tester Tester
- Use Cases - Test Data
- User Stories - Acceptance
Criteria Shared
? - Speciﬁcation
Understanding
- Use Cases
Mapping - User Stories
- Code Mapping - Code
- Unit Tests - Unit Tests
- Test Data - Test Data

Developer

Developer


Finding a common abstraction

Shared
Business Developer Tester Understanding

Business

Tester

Developer


Shared Understanding
• Terminology and abstractions of business
• Concrete enough for developers

• Business readable
• Bound to implementation
• Consistent

Speciﬁcation by example
• Abstract requirements and speciﬁcations are not a good tool
for communication. Real-life examples are much better.

• We mostly communicate by examples

• Usually examples are not formalized and not shared


Examples
• Enable developers and testers to
communicate efﬁciently with business
people
• Provide enough information for developers
to implement and for testers to verify
• Realistic examples contain precise
information and ask for precise answers
• Are a way to test speciﬁcations!

A new tool!

Agile Acceptance Testing

Acceptance Test Driven
Development

Behavior Driven
Development

Demo


Agile: new challenges!

Challenges

• Effort

• Regression

• Deﬁnition of Done

• Streaming Requirements

• Agile Planing

• Authoritative Source of Information


Effort

Effort

• Potentially shippable software each iteration

• Testing everything each iteration

• A lot of iterations -> a lot to test!

• Consequence: Automation is a must!


Regression

Regression

• Potentially shippable software each iteration

• High velocity, changes are embraced

• How to guarantee quality?

• Consequence: Automation is a must!


Deﬁnition of Done

Definition of Done
• When are we finished?

• Testing is an integral part of the development
process and not a separate discipline

• Implementation and testing have to work together
on a fine grained level

• There has to be an efficient communication between
implementation and testing

• Consequence: Relation between implementation and
testing has to be redefined!


Streaming Requirements

Streaming Requirements
• Not all of the requirements are delivered upfront

• Requirements are delivered just in time

• Incrementally reveal details just-in-time

• Pull instead of push

• Embrace Change

• Consequence: Requirements providers
(stakeholders) must ﬁnd a new way to deliver
requirements


Agile Planning

Agile Planning
• Goal-driven instead of scope-driven

• How to plan something when the scope is
uncertain?

• Managing changes and uncertainty

• You don’t know what can be tested when...

• Consequence: Testers and developers have to
interact on a ﬁne grained and self organized level


Authoritative Source of Information

Authoritative Source of
Information
• Avoid excessive, disconnected artifacts. The source code is
the artifact that ultimately matters.

• No specification, no documentation doesn’t work either!

• Communication is more important than documentation

• But people as the only source of information is not an
option

• Consequence: Find a way for efficient specifications and
documentation that is connected to the source code.

Müssen Entwickler Braucht es noch Tester?
jetzt Testen?

JA!

Entwickler...
• Bindet Beispiele and die
Implementierung
• Worauf gebunden wird ist
ﬂexibel!


Tester ...
• Bringen Beispiele in eine
testbare Form
• Kollaboration mit Stakeholders
• Mindestens ein Beispiel pro
Feature
• Economy of Scale
• Entwickeln die Tessprache
• Nutzung auch für manuelle
Tests


Manuelle
Tests ...
• Zur Validierung von Main-Flows
und Integration
• Demo an Stakeholder
• Geringere Anzahl
• Unterstützt durch „Testsprache“
• Automatisierung aufwändiger!


Aufwand?
• Ca. 15% des Gesamtaufwands für
Testspeziﬁkation
-> 1 Tester versorgt 6-7 Entwickler

• Entwickler: 10-25% Aufwand für
Binding
-> Synergien


Wartbarkeit?
• Richtiger Abstraktionsgrad
• Wiederverwendbarkeit von Bindings
• Ebene der Bindings


Why are tests
important?
"Nothing makes a system
more flexible than a
comprehensive suite of
tests! Far above good
architecture and good
design!"
- Robert C. Martin, Oredev, 2008

http://archive.oredev.org/topmenu/video/keynotebobmartin.4.5a2d30d411ee6ffd28880002007.html

Testing is more than QA!
• Regression Tests enable change

• TDD: Drive the design through tests

• Tests are examples that enable customer interaction

• Tests are examples that can be the specification

• Tests are examples that document the system

• ATDD: Drive the specification through acceptance
tests

• Tests can be the definition of ‘done’


The Topic is Hot!

www.cukes.info www.concordion.net

www.fitnesse.org www.specflow.org

JBehave / NBehave
http://studios.thoughtworks.com/agile-test-automation


Resources

The RSpec Agile Testing
Book

Bridging the
communication gap


BDD is a Mindset not a
Tool!


Viel Erfolg beim Einsatz von
Behavior Driven
Development und Agilen
Akzeptanztests!

Jonas Bandi
Software Architect
TechTalk
jonas.bandi@techtalk.ch
blog.jonasbandi.net
www.techtalk.ch twitter.com/jbandi

Testing: Chances and Challenges in an agile World

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