Performance Testing in Waterfall and Agile Methodologies

While developing software, every team will have to determine that point of time where performance testing of the product will benefit them most. The challenge here is to figure out where software testing should begin – from the beginning of the project, parallel to development or at the end of development?

Obviously, this depends on the software development methodology adopted by the development company. The methodology also applies to testing. Generally, developers either go for the Agile methodology or the Waterfall approach.

In the Agile approach, testing especially performance testing is started at the beginning of the development process and goes along with the development till the end. The waterfall approach is where testing is done only at the end after development.

Let’s look into both testing approaches in detail.

Waterfall Methodology – Pros & Cons

Though Agile has taken over the modern software development sector, many companies still practice the Waterfall model. As mentioned before, performance testing is done only at the end of the development process in the waterfall approach.


  • Easier to plan the testing and allocate resources since it’s done only at the end of development.
  • Typically uses test environments that share many similarities with the production environment.
  • Testing can focus on specific characteristics of the product based on priority.


  • Testing environment being similar to that of production makes it challenging to procure infrastructure exclusively for testing purposes.
  • Might demand architectural changes toward the end of development as testing also occurs at the end, which would in turn increase cost.
  • The team and the client would have to wait till the end to get assurance on performance which is also risky. Should the team identify major bugs in the system, they’d have to fix it before release which could essentially lead to failure in release by the deadline.

Agile Methodology – Pros & Cons

There is a reason why Agile development services enjoy great demand today. However, along with all its benefits, Agile does come with a fair share of challenges. In an Agile approach, testing begins right from the beginning of development with unit testing. Implementing continuous integration into development makes the entire process much faster, transforming simple performance testing to ‘performance engineering’.


  • Reduced risk
  • Early, constant feedback.
  • Continuous improvement, where testing finds bugs that are rectified in successive sprints.
  • Facilitates continuous integration.


  • Requires more effort in maintaining scripts and handling automation.
  • Automating less or more can lead to complications. The best practice is to automate critical test cases at the GUI level.
  • More testing effort where the team has to test components individually, and then test them working together to achieve optimal results.

Making the choice

Choosing the development approach requires us to consider the desired outcome and the project’s deadline. There are other important factors as well including the people who are going to work on the project, the technology that’s going to be leveraged, the development and testing tools that would be used, the processes involved etc.

Testing for Waterfall & Agile

Testing processes generally include test design, test automation, test execution, and test measurement.

For Waterfall

Software testing in waterfall development requires the tester to execute a load simulation at the end. With the simulation, the tester can:

  • Verify whether existing system supports a certain load
  • Give proof to the client as to how the system meets a predetermined standard for performance.
  • Check if the application requires some tweaking for the context where it will run.

For Agile

Performance testing is essentially ‘performance engineering’ in Agile, which reduces both cost and risks. It allows the team to understand the concept of performance engineering while executing it throughout the development cycle.


At the end of the day, we can’t choose one testing approach over the other though this isn’t the case when it comes to development. Early performance testing and load simulation for acceptance testing are both important, and needs to be part of the testing strategy depending on how far the development has progressed.

This blog explores the two most commonly practiced testing approaches – Waterfall and Agile, and where performance testing fits in both.

Making the choice between Waterfall and Agile performance testing is not easy. This blog shares some insights on both approaches and where performance testing fits in them.