SOFTWARE TESTING LEVELS

Levels of Testing:

There are five levels of testing

1. Unit Level Testing

2. Module Level Testing

3. Integration Level Testing

4. System Level Testing

5. System integration level testing

6. User Acceptance Testing (U.A.B)

1. Unit Level Testing: -

      It is a level of testing in which one will perform testing on the units. It is a white box testing and usually developers or white box testers will perform.

2. Module Level Testing: -

Module: Module is defined as a group of related functionalities to perform a major task

It is a level of tasting in which one will perform testing on the modules. It is a black box testing and usually test engineers perform it.

3. Integration Level Testing: -

      It is a level of testing in which the developers will develop some interfaces to integrate the modules and test whether the interfaces are working fine or not. It is a white box testing usually developers or white box tasters perform.

     

The developers may follow one of the following approaches while integrating the modules.

      1. Top-down approach

      2. Bottom –up approach

      3. Hybrid or Sandwich approach

      4. Bigbang approach

1. Top-down approach: - In this approach one will develop the parent modules first and then integrate them with the related child modules

2. Bottom-up approach: - In this approach one will develop the child modules first and integrate them to the parent modules

3. Hybrid approach Or Sandwich approach:- This is a mixed approach of both the top down and bottom up approaches

4. Big bang approach:-In this approach one will wait till all the modules are ready and finally they will integrate all the modules at a time

ÞSTUB: - While integrating the modules in top down approach if at all any mandatory module is missing then that module is replace with a temporary program known as STUB

ÞDRIVER: -While integrating the modules in bottom up approach. If at all any mandatory module is missing then that module is replaced with a temporary program known as DRIVER

4. System Level Testing: 

      It is a level of testing in which one will install the complete application in to the environment and then perform testing on it. At this level different types of testing will be done one among those is system integration testing.

5. System integration Testing: -

     It is a type of testing in which once the complete application is developed one will perform an action at one module and checks for the reflections at the corresponding modules. It is a black box testing and usually test engineers perform.

6. User- Acceptance Testing: -

     It is the level of testing in which one will perform the same system testing in the presence of the user in order to make him accept the application. It is a black box testing and usually Test engineer performs it.