A Guide To Top Software Testing Models: Which One Is The Best?

Software Testing Models

Software testing models are strategies and testing frameworks used to certify that the application under test meets client expectations. Software testing is a mandatory part of the software development cycle, making quality analysis impossible to ignore.

Various models are used in the software development process, where each model has its advantages and disadvantages. This article will be looking at each software testing model and its advantages and disadvantages. Lastly, which software testing model is the best? We’ll cover that too. So let’s get started.

Software Testing Models

5 Types of Software Testing Models

1. Waterfall Model

In the waterfall software testing model, a team of testers conducts small steps, one after another. The software development sequentially progresses through various phases. Firstly, a project is written down and planned. The next phase begins only after the earlier stage is completed. The waterfall model constitutes the following phases:

  • Requirement Analysis
  • Analysis phase
  • Software design
  • Programmed implementation
  • Testing
  • Maintenance


  • It is easy to implement and sustain.
  • The initial phase of rigorous investigation of requirements and systems helps save time later in the development stage.
  • The demand for resources is minimal.
  • Testing is carried out after each phase has been completed.


  • It is impossible to alter or change requirements.
  • You cannot make changes once you move to the next phase.
  • The next stage is not started until the preceding stage is completed.

2. Verification and Validation Methodology (V-Model)

In the V software testing model, the development and test execution activities are carried out simultaneously. Furthermore, testing starts at the unit level and spreads towards the entire system. Experts claim that this model is better than the waterfall model.


  • It saves time and enhances the chances of success.
  • Activities like planning and testing are done before coding, hence making this model easy to use.
  • Defects are usually found at an early stage, and a downward flow of defects is avoided.


  • It is an inflexible model.
  • Early prototypes are not available.
  • If there are any changes in the midway, you need to update the test document.

3. Incremental Model

The Iterative or Incremental Model is built on repetitions. The testing process consists of multiple iterations. Each of these cycles includes several parts. Each iteration adds value to the product. This model consists of three stages:

  • Design and development
  • Testing
  • Final implementation

The incremental model’s main benefit is that it is relatively flexible, so a testing team can quickly make edits into the testing process. Click here to find out more about software testing improvement ideas.


  • Ensure customer satisfaction with the rapid and continuous development of deliverables.
  • Working software can be developed quickly.
  • Products can be adapted to changing requirements regularly.
  • Test feedback is immediately available at the end of each cycle, making it a flexible model.


  • It may become difficult to examine the effort required at the beginning of the cycle.
  • Increased communication overheads as frequent repetitions take up resources quickly.

4. Spiral Model

The spiral model has four phases – planning, risk analysis, engineering, and evaluation. It emphasizes more on risk analysis. 

Each cycle begins after the previous one ends. After the last stage of each process, teams get immediate test feedback, so the quality of the product remains high. Every upper spiral builds on the base level spiral. This model allows testing teams to find errors quickly and rectify them. 


  • Importance is given to risk analysis.
  • It’s suitable for complex and large systems.
  • Additional functionalities can be added later on.
  • Software is produced early in the cycle.


  • It’s an expensive model and requires highly specialized risk analysis experts.
  • It does not work well on simple projects.

5. Extreme Programming

Extreme programming is a software testing model based on short development cycles. A project is divided into simple tasks. Feedback from the customer is incorporated, and the developers proceed with the next task. In extreme programming, developers usually work in pairs.


  • Customers having a preliminary software design in mind could use extreme programming.
  • Continuous testing and continuous integration of minor releases ensure software code is delivered of the superior build.


  • Meetings between the software development team and clients add to the timeline.

Which Software Model Should You Choose?

When it comes to software testing models, a one-size-fits-all approach doesn’t work. Each testing technique and model is designed for a specific purpose and has its relative merits and demerits. A particular model’s selection depends on many factors such as the nature of a project, client requirement, project schedule as well as specific needs of your project.

The spiral model is a good choice for large projects that might require features to be added along the way. On the contrary, the waterfall model is best suited for smaller projects where the requirements are precise, and there’s no need to change them quickly. The Iterative and Incremental methods match large projects where initial versions of the software are generated early on, facilitating customer evaluation and feedback.