System Testing

System testing is testing conducted on a complete, integrated system to evaluate the system's compliance with its specified requirements. System testing falls within the scope of Black box testing and as such, should require no knowledge of the inner design of the code or logic. System testing should be performed by testers who are trained to plan, execute, and report on application and system code. They should be aware of scenarios that might not occur to the end user, like testing for null, negative, and format inconsistent values.
System testing is actually done to the entire system against the Functional Requirement Specifications (FRS) and/or the System Requirement Specification (SRS). Moreover, the System testing is an investigatory testing phase, where the focus is to have almost a destructive attitude and test not only the design, but also the behavior and even the believed expectations of the customer. It is also intended to test up to and beyond the bounds defined in the software/hardware requirements specification.
Types of System Testing:

Types of Testing:
• Sanity Testing
• Compatibility Testing
• Recovery Testing
• Usability Testing
• Exploratory Testing
• Adhoc Testing
• Stress Testing
• Volume Testing
• Load Testing
• Performance Testing
• Security Testing

Sanity Testing
Testing the major working functionality of the system whether the system is working fine for the major testing effort. This testing is done before the testing phase and after the coding. The tests performed during sanity testing are
Compatibility Testing
Testing how well software performs in a particular hardware/software/operating system/network/environment etc.
Recovery Testing
Recovery testing is basically done in order to check how fast and better the application can recover against any type of crash or hardware failure etc. Type or extent of recovery is specified in the requirement specifications.
UsabilityTesting:
This testing is also called as ‘Testing for User-Friendliness’. This testing is done if User Interface of the application stands an important consideration and needs to be specific for the specific type of user.
ExploratoryTesting:
This testing is similar to the ad-hoc testing and is done in order to learn/explore the application.
Ad-hocTesting:
This type of testing is done without any formal Test Plan or Test Case creation. Ad-hoc testing helps in deciding the scope and duration of the various other testing and it also helps testers in learning the application prior starting with any other testing.
StressTesting:
The application is tested against heavy load such as complex numerical values, large number of inputs, large number of queries etc. which checks for the stress/load the applications can withstand.
VolumeTesting:
Volume testing is done against the efficiency of the application. Huge amount of data is processed through the application (which is being tested) in order to check the extreme limitations of theSystem.
LoadTesting:
The application is tested against heavy loads or inputs such as testing of web sites in order to find out at what point the web-site/application fails or at what point its performance degrades.
UserAcceptanceTesting:
In this type of testing, the software is handed over to the user in order to find out if the software meets the user expectations and works as it is expected to.
AlphaTesting:
In this type of testing, the users are invited at the development center where they use the application and the developers note every particular input or action carried out by the user. Any type of abnormal behavior of the system is noted and rectified by the developers.

BetaTesting:
In this type of testing, the software is distributed as a beta version to the users and users test the application at their sites. As the users explore the software, in case if any exception/defect occurs that is reported to the developers.








Testing Techniques

Manual Testing Technique:

This method of testing is done manually by the tester on the application under test
Why do manual testing?
Even in this age of short development cycles and automated-test-driven development, manual testing contributes vitally to the software development process. Here are a number of good reasons to do manual testing:
• By giving end users repeatable sets of instructions for using prototype software, manual testing allows them to be involved early in each development cycle and draws invaluable feedback from them that can prevent "surprise" application builds that fail to meet real-world usability requirements.
• Manual test cases gives testers something to use while awaiting for the construction of the application
• Manual test cases can be used to provide feedback to development teams in the form of a set of repeatable steps that lead to bugs or usability problems.
• If done thoroughly, manual test cases can also form the basis for help or tutorial files for the application under test.
• Finally, in a nod toward test-driven development, manual test cases can be given to the development staff to provide a clear description of the way the application should flow across use cases.
In summary, manual testing fills a gap in the testing repertoire and adds invaluably to the software development process.
Test automation is the use of software to control the execution of tests , the comparison of actual outcomes to predicted outcomes, the setting up of test preconditions, and other test control and test reporting functions. Commonly, test automation involves automating a manual process already in place that uses a formalized testing process.
Over the past few years , tools that help programmers quickly create applications with graphical user interfaces have dramatically improved programmer productivity. This has increased the pressure on testers, who are often perceived as bottlenecks to the delivery of software products. Testers are being asked to test more and more code in less and less time. Test automation is one way to do this, as manual testing is time consuming. As and when different versions of software are released, the new features will have to be tested manually time and again. But, now there are tools available that help the testers in the automation of the GUI which reduce the test time as well as the cost, other test automation tools support execution of performance tests.
Many test automation tools provide record and playback features that allow users to record interactively user actions and replay it back any number of times, comparing actual results to those expected. However, reliance on these features poses major reliability and maintainability problems. Most successful automators use a software engineering approach, and as such most serious test automation is undertaken by people with development experience.
A growing trend in software development is to use testing frameworks such as the xUnit frameworks (for example, JUnit and Nunit which allow the code to conduct unit tests to determine whether various sections of the code are acting as expected in various circumstances. Test cases describe tests that need to be run on the program to verify that the program runs as expected. All three aspects of testing can be automated.
Another important aspect of test automation is the idea of partial test automation, or automating parts but not all of the software testing process. If, for example, an oracle cannot reasonably be created, or if fully automated tests would be too difficult to maintain, then a software tools engineer can instead create testing tools to help human testers perform their jobs more efficiently. Testing tools can help automate tasks such as product installation, test data creation, GUI interaction, problem detection (consider parsing or polling agents equipped with oracles), defect logging, etc., without necessarily automating tests in an end-to-end fashion.
Test automation is expensive and it is an addition, not a replacement, to manual testing. It can be made cost-effective in the longer term though, especially in regression testing. One way to generate test cases automatically is model-based testing where a model of the system is used for test case generation, but research continues into a variety of methodologies for doing so.