Way of Software Testing

More defects => more chances of failure => lesser reliability

Faults & Failure

• —Failure: A software failure occurs if the behavior of the s/w is different from expected/specified.
• —Fault: cause of software failure
• —Fault = bug = defect
• —Failure implies presence of defects

Role of Testing

• —Reviews are human processes – can not catch all defects
• —Hence there will be requirement defects, design defects and coding defects in code
• —These defects have to be identified by testing
• —Therefore testing plays a critical role in ensuring quality.
• —All defects remaining from before as well as new ones introduced have to be identified by testing.

Detecting defects in Testing

• —During testing,  an application is executed with a set of test cases
• —Failure during testing => defects are present
• —No failure => confidence grows, but can not say “defects are absent”
• —Defects detected through failures
• —To detect defects, must cause failures during testing

Special cases

• —Application often fail on special cases
• —These depend on nature of inputs, types of data structures,etc.
• —No good rules to identify them
• —One way is to guess when the software might fail and create those test cases
• —Also called error guessing.

make it perfect!