A much broader concept than you may think...

What do you really know about your software?

How do you know it?

Inescapably:

• If you don't design and develop for validation, there is no way to really know!

• If you don't design and develop for maintainability, there's no way to have it track your changing needs!

• Changes require validation of what it NOW does.

Essential disciplines:

If we don't have the right foundation for knowing what to test, why bother?
Only then can testing deliver truly useful knowledge.
Therefore, testing-specific disciplines are at the end of this list.

• Lean
  Lean Software Development

  - Disciplines for making a business effective
  and aligning software requirements with the business.

• Scrum and Kanban

  - Disciplines for rapidly discovering and 'building the right thing'.
  - Focusing cross-functional teams on delivering and validating the true value.
  - Making and keeping commitments to the business.
  - Measuring and rewarding teams as a unit.
  - Making management highly responsive to team needs.

• Extreme Programming (XP)

  - Disciplines for 'building things right'.
  - Discovering and building effective software architecture.
  - Continuously validating correctness.
  - Supporting team-ownership of the code - shared knowledge.

• Object Oriented Design (OOD)
  Object Oriented Programming (OOP)
  Design By Contract (DBC)

  - Disciplines for effective modularization and interfacing of modules.
  - Essential disciplines for maintainability and validation.

• Test Driven Design (TDD)
  Test Driven Development (TDD)
  Test-First Design(TFD)
  Test-First Development (TFD)

  - Disciplines for creating executable requirements and automated validation at all levels of integration from unit tests to acceptance tests.
  - Test-First to constrain development effort to just what the project sponsors want to pay for (both business and technical).

• Framework for Integrated Tests (Fit)
  FitNesse

  - Fit is an open-source tool for automated customer tests.
  - Fit automatically compares customers' expectations to actual results.
  - Customers' examples are formatted in tables and saved as HTML using tools such as Microsoft Excel.
  - Fit colors the tables green, red, and yellow according to whether the software behaved as expected.
  - FitNesse is a self-contained, fully integrated, wiki and acceptance testing framework based upon Fit.