Waterfall SDLC model


What is the Waterfall SDLC model?

The waterfall model is one of the oldest software development life cycles (SDLC). This is also known as ‘linear-sequential life cycle model’. In this model, the software project is divided into different phases, and each phase has its own objectives and tasks. Each phase starts only when the previous stage completes. The different phases in waterfall model are as below:

Each stage depends on the deliverables of the previous stage.

  • Requirement gathering and Analysis Phase
  • Design Phase
  • Coding/Development Phase
  • Testing/Verification Phase
  • Maintenance Phase
waterfall SDLC model - testing services

When to use the Waterfall model?

The waterfall model is mainly useful when
  • The software application is small, and the requirements are clear
  • The requirements, tools, and techniques used are stable and not dynamic
  • A number of experienced resources are available to support the software product

Testing Phase in the Waterfall software development model

In this model, the testing phase starts when the software product is ready as per the requirement document. Unit testing, Integration, and Acceptance testing are the most common types of testing. These testing methods ensure that the software is defect-free and fully meets the requirements specified in the requirement document. Errors found during testing are escalated to the development team to fix it.

Advantages and Disadvantages


  • Simple and easy to understand
  • Clear milestones and well defined stages
  • Well documented process and results


  • Not suitable for complex projects
  • Change of requirements is not possible
  • High risk and uncertainty

   At QAonCloud, we provide testing services based on your SDLC model  and your requirements.