In the world of software testing, system testing is the testing of a complete and fully integrated software product.
Usually software is only one element of a larger computer based system. Ultimately, software is interfaced with other software/hardware systems. System testing is actually a series of different tests whose sole purpose is to exercise the full computer based system.
System testing falls under the black box testing category of software testing. White box testing is the testing of the internal workings or code of a software application. In contrast, black box or system testing is the opposite.System testing involves the external workings of the software from the user's perspective.
What do you verify in System Testing ?
That is a very basic description of what is involved in system testing. You need to build detailed test cases and test suites that test each aspect of the application as seen from the outside without looking at the actual source code.
The Software Testing Hierarchy
As with almost any technical process, software testing has a prescribed order in which things should be done. The following is a list of software testing categories arranged in chronological order. These are the steps taken to fully test new software in preparation for marketing it:
- Unit testing - testing performed on each module or block of code during development. Unit testing is normally done by the programmer who writes the code.
- Integration testing - testing done before, during and after integration of a new module into the main software package. This involves testing of each individual code module. One piece of software can contain several modules which are often created by several different programmers. It is crucial to test each module's effect on the entire program model.
- System testing - testing done by a professional testing agent on the completed software product before it is introduced to the market.
- Acceptance testing - beta testing of the product done by the actual end users.
Types of System Testing
There are more than 50 types of System Testing. For an exhaustive list of software testing types click here. Below we have listed types of system testing a large software development company would typically use
- Usability Testing - Usability testing mainly focuses on the user's ease to use the application, flexibility in handling controls and ability of the system to meet its objectives
- Load Testing - Load testing is necessary to know that a software solution will perform under real life loads.
- Regression Testing - Regression testing involves testing done to make sure none of the changes made over the course of the development process have caused new bugs. It also makes sure no old bugs appear from the addition of new software modules over time.
- Recovery Testing - Recovery testing is done to demonstrate a software solution is reliable, trustworthy and can successfully recoup from possible crashes.
- Migration Testing - Migration testing is done to ensure that the software can be moved from older system infrastructures to current system infrastructures without any issues.
- Functional Testing - Also known as functional completeness testing, functional testing involves trying to think of any possible missing functions. Testers might make a list of additional functionalities that a product could have to improve it during functional testing.
- Hardware/Software Testing - IBM refers to Hardware/Software testing as "HW/SW Testing". This is when the tester focuses his/her attention on the interactions between the hardware and software during system testing.