Software Testing and Quality Assurance 1

What is the objectives of Software Testing?

Direct Objectives To identify and reveal as many errors as possible in the tested software To bring the tested software, after correction of the identified errors and retesting to an acceptable level of quality To perform the required tests efficiency and effectively, within budgetary and scheduling limitation

Indirect Objective To compile a record of software errors for use in error prevention (by corrective and preventive actions)

Stages of Testing Module or unit testing. Integration testing, Function testing. Performance testing. Acceptance testing. Installation testing.

Testing Strategies We began by 'testing-in-the-small' and move toward 'testing -in-the-large' For conventional software – The module (component) is our initial focus – Integration of module follows For OO software – OO class that include attributes and operations and implies communication and collaboration

Static Testing Static testing refers to testing that takes place without Execution - examining and reviewing it. Dynamic Testing Dynamic testing is what you would normally think of testing - executing and using the software.

Dynamic Testing Techniques used are determined by the type of testing that must be conducted – Functional – Structural

Functional Testing Structure of the program is not considered. Test cases are decided based on the requirements or specification of the program or module Hence it is often called as “Black Box Testing”.

Structural Testing Concerned with testing,the implementation of the program. Focus on the internal structure of the program. The intent of structural testing is not to exercise all the different input or output condition but to exercise the different programming structures and data structures in the program.

Testing Levels Phases of software testing: – Unit Testing – Integration/Build Testing – Validation/Functional Testing – System Testing – Acceptance Testing

Software Test Classification Software test may be classified – according to the testing concept or – to the requirement classification

According to Testing Concept What concept to test? – Output Output is used to archive an acceptable level of quality – Structural of the software Internal structural and calculations involved is included for satisfactory testing Two Classes have been developed – Black box testing Identify bug according to software malfunctioning Functionality testing – White box testing Examine internal calculation paths in order to identify bug Structural testing

According to Requirement The test id carried out to ensure full coverage of the respective requirement – Operation Correctness, Reliability, Efficiency, Integrity, Usability – Revision Maintainability, flexibility, testability – Transition Portability, reusabilily, interoperability From the requirement we can define the test classification White box and black box can be used implemented respectively

Test Classification according to Requirement Correctness 1.1 Output correctness tests 1.2 Documentation tests 1.3 Availability tests 1.4 Data processing & calculations correctness tests 1.5 Software qualification tests Reliability2. Reliability tests Efficiency3. Stress test (load tests and durability tests) Integrity4. Software system security tests Usability 5.1 Training usability tests 5.2 Operational usability tests Maintainability6. Maintainability tests Flexibility7. Flexibility tests Testability8. Testability tests Portability9. Portability tests Re usability10. Re usability tests Interoperability 11.1 Software interoperability tests 11.2 Equipment interoperability test

Test Classification according to Requirement Correctness 1.1 Output correctness tests 1.2 Documentation tests 1.3 Availability tests 1.4 Data processing & calculations correctness tests 1.5 Software qualification tests Reliability2. Reliability tests Efficiency3. Stress test (load tests and durability tests) Integrity4. Software system security tests Usability 5.1 Training usability tests 5.2 Operational usability tests Maintainability6. Maintainability tests Flexibility7. Flexibility tests Testability8. Testability tests Portability9. Portability tests Re usability10. Re usability tests Interoperability 11.1 Software interoperability tests 11.2 Equipment interoperability test

IEEE definitions Black box testing Testing that ignores the internal mechanism of the system or component and focuses solely on the outputs in response to selected inputs and execution conditions Testing conducted to evaluate the compliance of a system or component with specified functional requirements White box testing Testing that takes into account the internal mechanism of a system or component

Unit Testing Program reviews. Formal verification. Test each module individually. Testing the program itself. – black box and white box testing.

Black Box or White Box? Maximum # of logic paths - determine if white box testing is possible. Nature of input data. Amount of computation involved. Complexity of algorithms.

Unit Testing 20 module to be tested test cases results softwareengineer

Unit Testing Details Interfaces tested for proper information flow. Local data are examined to ensure that integrity is maintained. Boundary conditions are tested. Basis path testing should be used. All error handling paths should be tested. Drivers and/or stubs need to be developed to test incomplete software.

Generating Test Data Ideally want to test every permutation of valid and invalid inputs Equivalence partitioning it often required to reduce to infinite test case sets – Every possible input belongs to one of the equivalence classes. – No input belongs to more than one class. – Each point is representative of class.