SOFTWARE TESTING STRATEGIES:
- 1. SOFTWARETESTING STRATEGIES: 1. This refer to how apply and when to apply various testing technique. 2. This provides a road map that describes step’s to be conducted as a part of testing, when these steps are planned and then undertaken how much time and resources will be required. 3. The strategy for software testing may be 1. Unit testing 2. Validation testing 3. Integration testing 4. System testing 1. UNITTESTING: It is also called module testing. This method is applied to individual program modules to ensure that information properly flow into and out of the program unit. In this the main focus is on the component. This is white box testing in which each component is independently tested. In this at each component five items are tested. Interface Local data structure Boundary checks Independent paths Error handling paths 2. Integration Testing: 1. Integration testing modules are tested chunks or groups. 2. Once individual program components have been tested. 3. During Integration testing a question arise that if a module in unit test work properly then why we use these modules when they are combine in groups? 4. Answer can be clear from the following reasons. Impact of global data Interface problem in groups Sub functions when data combine may not produce the desire function. 5. Integration testing can be performed in two ways Big bang approach Incremental approach 6. BIG BANG APPROACH OR NON INCREMENTAL in this approach all the components are combined I advance and the entire program is tested as a whole, but this is not efficient. This main difficulty that arises in integration
- 2. testing in locating errors there are complex interactions between the system components and when an unexpected output is discovered, it may be hard to find the source of the error. 7. INCREMENTAL APPROACH: in this approach the program is constructed and tested in small increments. I.e. start from minimum components and then add the components after each increment. 8. Incremental integration strategies are: Top down integration Bottom up integration Regression testing Smoke testing TOP DOWNINTEGRATION: 1. Top down integration is an incremental approach to construction of the program structure. 2. As its name indicate. In this the modules are integrates by moving downward through the control hierarchy beginning with the main control module (main program). (Diagramfrom lecture) 3. Top-down integration may be conducted as: Depth first integration or Breath first integration 4. DEPTH FIRST: depth first integration would integrate modules on a major control path of structure. 5. BREADTH FIRST: this is a level by level integration. Breadth-first integration would integrate all modules directly subordinate at each level, moving across the structure horizontally. BOTTOMUP INTGRATION: The bottom up the process is performed in the following steps: 1. Low-level module or components are combined into clusters or builds that perform a specific software sub function. 2. Then a driver (a control program for testing) is written to co-ordinate a. Test cases b. Input and output 3. The cluster is tested. 4. Drivers are removed and clusters are combined moving upward in the control hierarchy. REGESSIONTESTING: Each time when a new module is added as a part of integration test the software changes.
- 3. New data flow path are established New I/O may occur New control logic is invoked In order to avoid this regression test are used. It is re-execution of some subset of tests that have already been conducted to ensure that changes have not side effects. SMOKETESTING: 1. Smoke testing is an integration testing approach that is commonly used. 2. This testing issued for time critical projects. ADVANTAGES: Integration risk is minimized because this test is conducted daily and errors can be uncovered early. The quality of the product is improved because this testing uncovered functional errors, architectural error and component level design defects. 3. VALIDAIONTESTING: 1. At the end of integration testing the software is assembled as a complete package to ensure that interface and other related errors have been detected and corrected and a final test is done called validation test. 2. Validation testing is also used to uncover error but it focuses on the requirement level that whether it fulfills the requirements of the user or not. 3. Here The Requirements Of The User Are The Software Function Expected By The User. VALIDATIONCRITERIA: 1. Here two steps are followed: 2. A test plan outlines the classes of tests to be conducted. 3. A test procedure defines specific test cases that are used to demonstrate conformity with requirements. 4. After validation test one of two possible conditions exist. a. Software fulfills the requirements of the user. b. Software fails to fulfill the requirements of the user i.e. a deviation exist. ALPHA TESTING: This test is conducted at the developer’s site by the customer. In this testing software developer and customer are set shoulder by shoulder and error is recorded. BETA TESTING: Beta testing is conducted at more than one customer site by more than on end user. Unlike alpha testing listing developer is not present and a live
- 4. application of the software moves in environment. The end-users recorded the errors while using the product and reported these errors to developer. The developer modifies the software product and a final version is released to customer. 1. SYSTEM TESTING: 1. When a software is developed and tested then it is combined with other system elements e.g. hardware, operating system, people etc. 2. At this stage the software is tested with those system elements and the testing is called system testing. 3. The following tests are conducted in systemtesting; Recovery testing Security testing Stress testing performance testing, RECOVERY TESTING: Recovery testing is a systemtest that forces the software to fails in variety of ways and verify that where the recovery are properly performed or not.. SECURITY TESTING: Security testing is the most important feature in computer environment, Security testing is done to verify the protection mechanism built into a system that whether this protection mechanism it form improper . For this purpose password, authentication, etc. rules are followed. STRESS TESTGING: Black- box testing ad white box testing are carried out for normal condition but stress testing are carried out for abnormal condition, that whether the software product with work under these abnormal condition or not. PERFORMANCETESTING: This testing is conduct that whether the software performance are affected with the introduction of system’s new elements or not. In this technique run time performance of software is tested in the context of integrated system.