Three Agile Testing Methods – TDD, ATDD and BDD

by | 3.4 - AgileBI Process, Backlogged, Concepts

As a Product Owner or Developer
I want I want to understand the different Agile testing methods
So that I can decide which to use

In the word of Agile, there are currently three methods that can be used to improve our testing practices and to assist with enabling automated testing.

  • Test Driven Development (TDD)
  • Acceptance Test Driven Development (ATDD)
  • Behavior Driven Development (BDD)

TDD, ATDD and BDD are software development techniques that can be used in any methodology although aspects of all three are often part of a team’s agile approach.



Test Driven Development (TDD)

TDD ensures that the product, system or process is being built correctly.  It tests independent small units or objects to make sure each works as intended.

TDD is a software development approach where a developer writes a test before writing any code.  The test is then used to build the code needed to pass it.  Once the new code passes the test, it can be refactored to an acceptable standard (i.e. code layout, notation, performance)

TDD focus is “does the code do what it is required to do?”

Acceptance Test Driven Development (ATDD)

Acceptance Test Driven Development is also referred to as Story Test Driven Development (STDD)

ATDD ensures the product, system or process being built meets the expectation of the Product Owner.  It’s a mechanism to facilitate the conversation between developers and product owners about the requirements and validate the expected business value is met.

It is a collaborative practice where users, testers, and developers define acceptance criteria. ATDD helps to ensure that all project members understand precisely what needs to be done and implemented. In Scrum these are referred to as the Acceptance Criteria for each User Story.

ATDD focus is on does the solution do what it is required to do?

Behavior Driven Development (BDD)

BDD is often referred to as Specification by Example

BDD ensures the correct product, system or process is being built by writing specifications or examples that describe the behavior expected.

BDD tests are written in an english-like language.  Subject matter experts use their native language in combination with the language of Domain Driven Design to describe the purpose and benefit of their code.

A team using BDD should be able to provide a significant portion of “functional documentation” in the form of executable scenarios or examples. BDD is usually done in very English-like language helps the Domain experts to understand the implementation rather than exposing the code level tests. It’s usually defined in the format of: GIVEN WHEN AND THEN.


I recommend the use of a combination of ATDD and BDD.

  • ATDD
    Definition of Acceptance Criteria for each user story
  • BDD
    Definition of ???


Defining BDD ???

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