Discover Performance Testing
Learning Objectives
After completing this unit, you’ll be able to:
- Explain the differences between functional and non-functional testing.
- Explain performance testing and its benefits.
This module was produced in collaboration with Provar. Learn more about partner content on Trailhead.
Functional and Non-Functional Testing
One way to categorize application testing is into functional and non-functional testing classifications. Simply put, functional testing checks that the application does what it’s supposed to do, and non-functional testing checks how well it does it.
Functional testing is testing that the application meets business requirements and works as intended. Unit, integration, and system testing are all examples of test types that look at how the features of an application work according to the requirements.
In contrast, non-functional testing evaluates aspects that are not directly tied to the application’s functionality but are essential for the user experience. Examples of non-functional testing include usability and security testing.
Performance Testing
Performance testing is a form of non-functional testing. Teams conduct performance tests to assess the behavior of an application under various conditions and, ultimately, measure its efficiency.
For example, a website is selling concert tickets. It needs the seat selection, the shopping cart, and the payment processing to work. That’s all verified in the functional testing. The website also needs to be able to handle a certain number of users at the same time. And it must be able to perform necessary actions in a reasonable amount of time. This is all checked through performance testing.
Performance testing allows teams to gain insight into three key areas of their application.
- Scalability: Can it handle additional workload without compromising quality?
- Speed: How fast does it respond?
- Stability: Is it reliable under various workloads?
Performance Testing in Software Development
In the Agile Testing Quadrants, performance testing falls in the fourth quadrant, which includes technology-facing tests that critique the product. Teams invest in gathering this information for several reasons.
- Risk mitigation: Proactive performance testing can help identify problems before they present themselves to the end user. Typically, the earlier an issue is found, the easier it is to fix.
- User experience: An application that works and an application that works well are vastly different to the end user. An excellent user experience can become the competitive edge for a company.
- Brand reputation: An organization with a poorly performing website risks frustrating users and compromising the brand’s reputation. Optimal performance on a website or application benefits the brand.
- Revenue: A poor user experience can even lead to loss of revenue. If the website doesn't load quickly or handle a certain number of concurrent users, those users may opt for a competitor.
- Scalability planning: Understanding your current capacity helps you plan your future capacity. Learn more about your performance today to successfully grow it in the future.
Now you know that performance testing provides valuable information about the user experience. In the next unit, look at how each type of performance test answers a key question about the application.