System testing is the most difficult process to perceive and execute. It should not be identified with testing of an entire system or program. The purpose of the system test is to compare the actual result with the original targets. From here follow two conclusions:
When considering the differences between the result obtained and the original objectives of the program, the greatest attention is paid to identifying translation errors that occur during the development of the external specification.
Due to this, it is crucial to verify the system as the most errors, and quite serious ones occur namely at this stage. Unlike functional tests, system tests cannot be created based the external specification, since this would contradict the purpose of the system test. On the other hand, a document reflecting the objectives of the system as such cannot be used to develop tests for it: the doc by definition does not contain precise descriptions of the external interfaces of the program. The dilemma is resolved by using operational user documentation and other releases (publications). System tests are designed based on an analysis of its objectives and then written based on the results of review of user documentation. This practice is very useful because it allows you to compare not only the programs with the source document describing the purpose of its development, but also the results of its operation with user documentation, as well as user documentation with the source document.
Web application testing services deal with e-commerce sites to make sure that these do not contain bugs and perform flawlessly.
System testing is the most difficult part of the testing process. Its main task is to compare the program with the source document describing the purpose of its production. However, there is no universally accepted methodology for designing such tests. The source document establishes what exactly and how well the program should do, but does not specify how it should be represented.