What is Bottom - Up integration?

Every module in the lower levels is checked by a higher modules.This process is repeated until all modules at the top level of hierarchy are tested. High level module are checked with the help of drivers.Drivers are dummy modules which is replacement for the high level modules.

Bottom  Up Integration -  Flow Diagram

                                                                                               

        

Module 4, 5, 6, 7 are available and we use driver 1, driver 2, driver 3 (those are temporary created modules for integration) instead of module 1, 2, and 3.

  

     

Advantages:

• Test conditions are simple to make.
• Observation of test outcomes is simple to understand.
• Time is not wasted waiting for all modules to be developed. 

Disadvantages:

• An early prototype is not possible.
• Driver modules must be delivered.
• The program as a substance does not exist until the point when the last module included.