When we were looking for a job, we found that recruiting has some functional tests and recruiting has some performance tests. What is the difference between functional testing and performance testing ?
different focus
The focus of functional testing is whether the functionality meets the customer's needs.
For example, we get a demand for a festival event. There are many scenarios for this demand, such as percentage discount or full discount, whether there are coupons, whether the event can be used in combination, whether it can be used in combination, which preferential strategy is preferred, and so on.
When doing functional testing, we must identify these requirements and test all possible scenarios as much as possible. Functional testing focuses on every detail of the product.
Functional testing should ensure that there is no problem with each function point, and prevent customers from having problems during use in the production environment. Moreover, after the functional testing is completed, documents such as test cases , test summary reports, and user operation manuals need to be submitted to track the entire testing process.
In addition, functional testing pays more attention to customer experience. Test engineers should use functions from the customer's point of view, not from the developer's point of view, because it is the customer who really uses the system. Only by considering the customer's experience, the system can get bigger range promotion.
The focus of performance testing is whether the response speed can meet customer needs.
For performance testing, what we need to do is to analyze the operations that may cause bottlenecks, perform stress testing on them , or perform stress testing on the entire operation process of a requirement, and conduct online testing.
For the same requirements, we first need to analyze which points should be stress tested, such as checking orders, calculating coupons, selecting coupons, and submitting orders. If stress testing is required at these points, we need to add meeting points before these steps, set the number of concurrency, and check that response time, throughput, and system performance meet the requirements.
After the performance test is completed, according to the results of the performance test, analyze data such as the optimal number of users, the maximum number of users, and system performance, and analyze system bottlenecks and whether there is room for optimization based on the test data. The performance test is to ensure that the system can run stably and stably in the case of multi-user concurrent operating systems , and customers can have a good experience.
Let's show the difference between them more intuitively through test cases.
Scenario: Open a 50-10, 100-30 campaign, and only specified products can use coupons.
Functional test case:
Performance test case:
Of course, the performance indicators here are my own examples. In a real performance test, what kind of data will be given in the requirements.
From the listed functional and performance test cases, we can clearly see that functional test cases pay attention to details, and all corners and different scenarios must be tested, while performance tests pay more attention to data such as response time and throughput.
different time periods of participation
Functional testing runs through the entire development stage of the project, starting from requirement analysis , going through the writing of test cases, reviewing test cases, executing tests, bug regressions, sorting out test documents, etc., until the end of the project.
Performance testing is generally carried out later in the project. For example, when we get a requirement or project, if the basic functions in the early stage have not been perfected, performance testing is generally not performed.
Until the later stage of the project, when the function is basically realized and there are no fatal bugs, because the performance test is mainly to test the performance of the system or function, when the function has not been completed or there are problems, the performance test is meaningless.
Use different tools
Functional testing is divided into manual testing and automatic testing. In the case of manual testing, there is no need to use a tool, but to verify correct functionality by typing and checking the input.
In case of automated testing , we need to use tools (such as selenium, QTP , etc.) to record the script, and modify the script so that the script can be automatically tested based on the data we set.
Performance testing is mainly carried out through tools (such as Loadrunner, Jmeter , etc.). ).
The ultimate purpose of functional testing and performance testing is the same, and both hope that the system can run stably. Simple functional or performance testing is incomplete. In order to bring a better experience to customers, a system can be more perfect only if functional testing and performance testing are properly combined.