After a test plan has been developed, system testing begins by testing program modules separately, followed by testing bundled modules as a ...
After a test plan has been developed, system testing begins by testing program modules separately, followed by testing bundled modules as a unit. A program module may function perfectly in isolation but fail when interfaced with other modules.
System testing consists of the following steps
1. Program testing
2. String testing
3. System testing
4. System documentation
5. User acceptance testing
1. Program testing:
A program represents the logical elements of a system. For a program to run satisfactorily it must compile and test data correctly and work properly with other programs. Achieving an error-free program is the responsibility of the programmer. Program testing checks for two types of errors
- Syntax
- Logic
A syntax error is a program statement that violates one or more rules of the language in which it is written.
A logic error deals with incorrect data fields, out of range items and invalid combinations. When a program is tested the output is compared with the expected output. If there are any discrepancies, the sequence of instructions must be traced to identify the problem.
A logic error deals with incorrect data fields, out of range items and invalid combinations. When a program is tested the output is compared with the expected output. If there are any discrepancies, the sequence of instructions must be traced to identify the problem.
2. String Testing:
Programs are invariably related to one another and interact in a total system. Each program is tested to see whether it conforms to related programs in the system. Each portion of the system is tested against the entire module with both test and live data before the entire system is ready to be tested
3. System Testing:
System testing is designed to uncover weaknesses that were not found in earlier tests. This includes forced system failure and validation of the total system as it will be implemented by its users and operational environment. It begins with low volumes of transactions based on live data. The volume is increased until the maximum level for each transaction type is reached. The total system is also tested for recovery and fallback after major failures to ensure that no data are lost during emergency..
4. System documentation:
All design and test documentation should be finalized and entered in the library for future reference. The library is the central location for maintenance of the new system. The format, organization and the language for each documentation should be in line with the system standards
5. User acceptance Testing:
An acceptance test has the objective of telling the user on the validity and reliability of the system. It verifies that the system’s procedures operate to system specifications and that the integrity of vital data is maintained. User motivation and knowledge are critical for the successful performance of the system. Then a comprehensive test report is prepared. The report indicates the system’s tolerance , performance range, error rate and accuracy.