Testing Types – Non-Functional Testing

Non-functional testing includes, but is not limited to, performance testing, load testing, stress testing,  usability testing, maintainability testing, reliability testing and portability testing. It is the testing of “how” the system works.

Non-functional testing may be performed at all test levels. The term non-functional testing describes the tests required to measure characteristics of systems and software that can be quantified on a varying scale, such as response times for performance testing. These tests can be referenced to a quality model such as the one defined in ‘Software Engineering – Software Product Quality’ (ISO 9126).

Reliability testing: Reliability Testing is about exercising an application so that failures are discovered and removed before the system is deployed. The purpose of reliability testing is to determine product reliability, and to determine whether the software meets the customer’s reliability requirements.

Usability testing: In usability testing basically the testers tests the ease with which the user interfaces can be used. It tests that whether the application or the product built is user-friendly or not.

Load testing: A load test is usually conducted to understand the behavior of the application under a specific expected load. Load testing is performed to determine a system’s behavior under both normal and at peak conditions. It helps to identify the maximum operating capacity of an application as well as any bottlenecks and determine which element is causing degradation. E.g. If the number of users are in creased then how much CPU, memory will be consumed, what is the network and bandwidth response time.

Performance testing: Performance testing is testing that is performed, to determine how fast some aspect of a system performs under a particular workload. It can serve different purposes like it can demonstrate that the system meets performance criteria. It can compare two systems to find which performs better. Or it can measure what part of the system or workload causes the system to perform badly.

Stress testing: It involves testing beyond normal operational capacity, often to a breaking point, in order to observe the results. It is a form of testing that is used to determine the stability of a given system. It put greater emphasis on robustness, availability, and error handling under a heavy load, rather than on what would be considered correct behavior under normal circumstances. The goals of such tests may be to ensure the software does not crash in conditions of insufficient computational resources (such as memory or disk space).