Software testing

5. Level of Testing

There are different level of software testing Defined by a given environment Environment is a
collection of  people, hardware, software, interfaces, data etc.

The different level of testing are defined as
 Unit Testing
 Integration Testing
 System Testing
 Acceptance Testing
 Regression testing

5.1 Unit Testing

      A unit is smallest testable piece of software can be compiled, linked, loaded
      e.g functions/procedures, classes, interfaces – normally done by programmer
      Test cases written after coding
      Buddy testing is prefer to cover unit testing.

      5.2 Buddy Testing

      Team approach to coding and testing. One programmer codes the other tests and vice versa
      Test cases ‐ written by tester(before coding starts).
       Better than single worker approach
 Objectivity
 cross‐training
 Models program specification requirement

   5.3 Integration Testing

Test for correct interaction between different units systems ‐ built by merging existing libraries
modules coded by different people.
Bottom up integration testing
Use of drivers
Top down integration testing
Use of stubs
 It is done by developers/testers
 Test cases written when detailed specification is ready
 Test continuous throughout project
5.4 System Testing
 Test of overall interaction of components
 Find disparities between implementation and specification
 Usually where most resources go to
 Involves – load, performance, reliability and security testing
 It is done by test team
 Test cases written when high level design is ready
 It is done on a system test machine

5.5 Acceptance Testing
 Demonstrates satisfaction of user
 Users are essential part of process
 Done by test team and customer
 Done in simulated environment/real environment
5.6 Regression Testing
 On going process throughout testing lifecycle
 New bug‐fix breaks previously tested units?
 Perform regression test whenever program changes