Mumbai University > Computer Engineering > Sem 6 > Software engineering

Marks: 10 Marks

Year: Dec 2016

Objectives of Software Testing:

• Finding defects which may get created by the programmer while developing the software.
• Gaining confidence in and providing information about the level of quality.
• To prevent defects.
• To make sure that the end result meets the business and user requirements.
• To ensure that it satisfies the BRS that is Business Requirement Specification and SRS that is System Requirement Specifications.
• To gain the confidence of the customers by providing them a quality product.

Black box Testing:

Black box testing treats the system as a “black-box”, so it doesn’t explicitly use Knowledge of the internal structure or code. Or in other words the Test engineer need not know the internal working of the “Black box” or application.

Main focus in black box testing is on functionality of the system as a whole.

Tools used for Black Box testing:

Black box testing tools are mainly record and playback tools. These tools are used for regression testing that to check whether new build has created any bug in previous working application functionality. These record and playback tools records test cases in the form of some scripts like TSL, VB script, Java script, Perl.

Advantages of Black Box Testing:

– Tester can be non-technical.

– Used to verify contradictions in actual system and the specifications.

– Test cases can be designed as soon as the functional specifications are complete

Disadvantages of Black Box Testing:

– The test inputs needs to be from large sample space.

– It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult

– Chances of having unidentified paths during this testing

Integration Testing:

Integration Testing is a level of software testing where individual units are combined and tested as a group.

The purpose of this level of testing is to expose faults in the interaction between integrated units. Test drivers and test stubs are used to assist in Integration Testing.

Analogy:

During the process of manufacturing a ballpoint pen, the cap, the body, the tail and clip, the ink cartridge and the ballpoint are produced separately and unit tested separately. When two or more units are ready, they are assembled and Integration Testing is performed. For example, whether the cap fits into the body or not.

Approaches:

• Big Bang is an approach to Integration Testing where all or most of the units are combined together and tested at one go. This approach is taken when the testing team receives the entire software in a bundle. So what is the difference between Big Bang Integration Testing and System Testing? Well, the former tests only the interactions between the units while the latter tests the entire system.
• Top Down is an approach to Integration Testing where top level units are tested first and lower level units are tested step by step after that. This approach is taken when top down development approach is followed. Test Stubs are needed to simulate lower level units which may not be available during the initial phases.
• Bottom Up is an approach to Integration Testing where bottom level units are tested first and upper level units step by step after that. This approach is taken when bottom up development approach is followed. Test Drivers are needed to simulate higher level units which may not be available during the initial phases.
• Sandwich/Hybrid is an approach to Integration Testing which is a combination of Top Down and Bottom Up approaches.