Bottom up strategy just as the name itself clears, is the opposite of powerful top down strategy. This sort of mechanism starts with building and testing the modules first which are obviously comes under the category of low level, than definitely proceeding towards the working its way ups the hierarchy.
BOTTOM UP STRATEGY BENEFITS
The advantages of bottom up integration are like that:
1. There is never urgency or hurry for any kind of program stubs as we always start developing and testing with the definite or absolute modules.
2. Always Starting at the bottom of the hierarchy again means that the critical modules are generally built and tested first and therefore any errors or mistakes in these forms of modules are find out early in the process.
Apart from top-down integration, there are some disadvantages of this procedure too which are given below:
1. In respect to test the popular modules we have to always form the test drivers first because they are more confused than compare to stubs. Also in addition to test these modules they themselves have to be tested so more time and efforts are needed to accomplish this complicated task.
2. One big disadvantage of bottom up strategy is that in this sort of testing no working model can be represented or you can say guided or tested as far as several modules have been built. This again means that a little form of errors in any of the interface is cached very late in the process.