95. Software Testing

Software testing is oriented to "detection". It's examining a system or an application under controlled conditions. It's intentionally making things go wrong when they should not and things happen when they should not. Software Testing is an empirical investigation conducted to provide stakeholders with information about the quality of the product or service under test, with respect to the context in which it is intended to operate. This includes, but is not limited to, the process of executing a program or application with the intent of finding software bugs. Testing involves operation of a system or application under controlled conditions and evaluating the results (eg, 'if the user is in interface A of the application while using hardware B, and does C, then D should happen'). The controlled conditions should include both normal and abnormal conditions. Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldn't or things don't happen when they should. It is oriented to 'detection'.

Testing software is operating the software under controlled conditions, to (1) verify that it behaves “as specified”; (2) to detect errors, and (3) to validate that what has been specified is what the user actually wanted. Verification is the checking or testing of items, including software, for conformance and consistency by evaluating the results against pre-specified requirements. Error Detection: Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldn’t or things don’t happen when they should. Validation looks at the system correctness – i.e. is the process of checking that what has been specified is what the user actually wanted. The purpose of inspection is trying to find defects and problems mostly in documents such as test plans, specifications, test cases, coding etc. It helps to find the problems and report it but not to fix it. It is one of the most cost effective methods of software quality. There might be different numbers of people can join the inspections but normally one moderator, one reader and one note taker are mandatory.

In other words, validation checks to see if we are building what the customer wants/needs, and verification checks to see if we are building that system correctly. Both verification and validation are necessary, but different components of any testing activity. The definition of testing according to the ANSI/IEEE 1059 standard is that testing is the process of analyzing a software item to detect the differences between existing and required conditions (that is defects/errors/bugs) and to evaluate the features of the software item. The purpose of testing is verification, validation and error detection in order to find problems – and the purpose of finding those problems is to get them fixed. Quality Assurance makes sure the project will be completed based on the previously agreed specifications, standards and functionality required without defects and possible problems. It monitors and tries to improve the development process from the beginning of the project to ensure this. It is oriented to "prevention".

A primary purpose for testing is to detect software failures so that defects may be uncovered and corrected. This is a non-trivial pursuit. Testing cannot establish that a product functions properly under all conditions but can only establish that it does not function properly under specific conditions. The scope of software testing often includes examination of code as well as execution of that code in various environments and conditions as well as examining the aspects of code: does it do what it is supposed to do and do what it needs to do. In the current culture of software development, a testing organization may be separate from the development team. There are various roles for testing team members. Information derived from software testing may be used to correct the process by which software is developed.