The document provides an overview of agile and test-driven development. It begins by comparing waterfall and agile approaches, noting that agile uses short iterative cycles. It then defines agile as iterative and incremental, with continual revisiting of requirements and design. Common agile methodologies like Scrum and extreme programming are discussed. Test-driven development is introduced as writing tests before code to ensure requirements are met and prevent bugs. The benefits of agile and TDD for developers are more code proven to meet requirements and less time spent debugging.

1. Agile And Test Driven
Development

2. Agenda
1. Waterfall vs Agile
2. Agile intro
3. SCRUM
4. Test-Driven Development

3. ● You complete one phase (e.g. Design) before moving on to the next phase
(e.g. Development)
● You rarely aim to revisit a 'phase' once it's completed
Waterfall development

5. But ..
● You don't realize any value until the end of the project
● You leave the testing until the end
● You don't seek approval from the stakeholders until late in the day
This approach is highly risky, often more costly and generally less efficient than
agile approaches

6. Waterfall Vs Agile
● Waterfall model
phase by phase:
analysis > design > development >
testing and delivery of whole
functionality
● Agile model
analysis > design > development >
testing and delivery of a small
functional pieces in with short
cycles (Sprints)

8. Agile

9. what is agile ?
● In 1970, Dr. Winston Royce presented a paper entitled “Managing the
Development of Large Software Systems.
● In February 2001, seventeen software developers met at the Snowbird resort
in Utah to discuss lightweight development methods. They published the
Manifesto for Agile Software Development.
● agile methodology is described as “iterative” and “incremental.”

10. what is agile ? ,continue
● In an agile paradigm, every aspect of development — requirements, design,
etc. — is continually revisited throughout the lifecycle.
● Agile methodology is an alternative to traditional project management,
typically used in software development. It helps teams respond to
unpredictability through incremental, iterative work cadences, known as
sprints. Agile methodologies are an alternative to waterfall, or traditional
sequential development.

11. Agile Development Cycle
● the initial planning
● analysis is kept to a
very high level
● analysing, designing,
developing and
testing

12. ● An iteration is simply a fixed, short period of time that the team chooses to
work within.
● Typically for agile teams, an iteration is between 1 week and 30 days.
● Strictly speaking, the Scrum agile development methodology advocates 30
days .
● The Extreme Programming agile methodology advocates 1 week.

14. ● inspect-and-adapt
● analysis paralysis
● Agile and stakeholders
Benefits of Agile

15. Types of agile:
● Scrum
● Kanban
● Extreme programming
● Lean software development

16. Agile principles
The Agile Manifesto is based on twelve principles:
1. Customer satisfaction by early and continuous delivery of useful software
2. Welcome changing requirements, even in late development
3. Working software is delivered frequently (weeks rather than months)
4. Close, daily cooperation between business people and developers
5. Projects are built around motivated individuals, who should be trusted
6. Face-to-face conversation is the best form of communication (co-location)

17. Agile principles ,continue
7. Working software is the principal measure of progress
8. Sustainable development, able to maintain a constant pace
9. Continuous attention to technical excellence and good design10.
10. Simplicity—the art of maximizing the amount of work not done—is essential
11. self-organizing teams
12. Regular adaptation to changing circumstance

18. Evolutions
● In 2009, Later, Ken Schwaber with others founded the Scrum Alliance and
created the Certified Scrum Master programs and its derivatives.

19. Scrum

20. Scrum
● Split your organization
● Split your work
● Split time

22. Things we do in Scrum ..
● Backlog
● User stories
● Work estimation
● Roadmap
● Daily scrum meeting

23. Daily Scrum meeting

24. Scrum planning example
● Iteration cycle of weeks
● Working hour per day is 8
● Product backlog of 20 stories
● Each story effort is 10 hrs
Total hours of work iteration can accommodate
= 8hrs x 5days x 3weeks = 120 hrs
● Iteration backlog or number of stories per iteration 12 user story

25. Test-Driven Development (TDD)

26. What is Test-Driven Development?
● In principle, it is just about writing the test before the program
● But in consequence, it leads the developer to:
○ first think about “how to use” the component (why do we need the component, what’s it for?)
○ and only then about “how to implement”.
● So, it’s a testing technique as well as a design technique
○ It results into components that are easy to test and enhance.
● In the end, there is no code without a test.

27. Motivation
● If you intend to test after you‘ve developed the system, you won‘t have the
time for testing. => Write the tests before the code!
● If things get complicated, you might fear that „the system“ doesn‘t work.
=> Execute the tests and get positive feedback (everything still works) or get
pointed to the bit that does not / no longer work.
● If you don‘t have tests for the code, you shouldn‘t use it / ship it.
=> This can‘t happen if you write the test first (so you reach
better test coverage than with functional tests).

28. Mechanics of TDD
● Always start with a failing test
● Quickly write the simplest code needed to pass the test
● Remove duplication
● Repeat as needed to meet requirements
● Test everything that could possibly break

29. What should be tested?
● Valid inputs
● Invalid inputs
● Errors, exceptions, and events
● Boundary conditions
● Everything that could possibly break!

30. TDD Benefits for Developers
● Much less debug time
● Code proven to meet requirements
● Don’t write any un-necessary code

31. Getting started with TDD
● Get some training
● Start with a small visible project
● Shoot for 100% test coverage
● Don’t expect to be perfect
● Expect to improve dramatically in time
● Measure the results

32. Thanks !