What is the difference between bottom-up and top-down
integraion?Which is effecive.
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Answer / suneel reddy
Difference is nothing Top down we start testing from amin
module without sub module (Stubs 4 sub modules)
In Bottom up we dont have main module we start testing with
sub module(Drivers are 4 main miodule)
Both have thier own advantages as wee as disadvantges
| Is This Answer Correct ? | 5 Yes | 1 No |
Integration testing:
Once the units have been written, the next stage would be to put them together to create the system. This is called integration.
It involves building something large from a number of smaller pieces.
The purpose of integration testing is to expose defects in the interfaces and in the interactions between integrated components or systems.
The test bases for integration testing can include:
1) The software and system design.
2) A diagram of the system architecture.
3) Workflows and use-cases.
The test objects would essentially be the interface code.
This can include subsystems' database implementations.
Before integration testing can be planned, an integration strategy is required.
This involves making decisions on how the system will be put together prior to testing.
There are three commonly quoted integration strategies, namely:
1) Big-Bang Integration.
2) Top-Down Integration.
3) Bottom-Up Integration.
Big-Bang Integration:
This is where all units are linked at once, resulting in a complete system.
When testing of this system is conducted, it is difficult to isolate any errors found, because attention is not paid to verifying the interfaces across individual units.
Top-Down Integration:
This is where the system is built in stages, starting with components that call other components.
Bottom-up Integration:
This is the opposite of top-down integration and the components are integrated in a bottom-up order.
There may be more than one level of integration testing.
For example:
Component integration testing focuses on the interactions between software components and is done after component (unit) testing.
Developers usually carry out this type of integration testing.
System integration testing focuses on the interactions between different systems and may be done after system testing of each individual system.
For example, a trading system in an investment bank will interact with the stock exchange to get the latest prices for its stocks and shares on the international market.
Testers usually carry out this type of integration testing.
It should be noted that testing at system integration level carries extra elements of risk.
These can include: at a technical level, cross-platform
issues; at an operational level, business workflow issues; and at a business level, risks associated with ownership of regression issues associated with change in one system possibly having a knock-on effect on other systems.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / sitam jana
Bottom up integration testing is an incremental approach to integration testing where the lowest level components are tested first,and then used to facilitate the testing of higher level components.
Top down integration testing is an incremental approach to
integration testing where the component at the top of the
component hierarchy is tested first, with lower level
components being simulated by stubs. Tested components are
then used to test lower level components.
| Is This Answer Correct ? | 1 Yes | 0 No |
Generally products are developed with Bottom up approach.
Say we have have to deliver one application contains 10
modules. One by one module is develpoed and need to be
tested. but how will you invoke that singe module, you will
be needing Driver to invoke it. As sooner other modules
will finished they will be integrated with it and
similarily you will have complete application.
In top down you will have main module is ready to
accomodate other modules that are getting develpoed
simultaneously.
Correct me if i m wrong
| Is This Answer Correct ? | 0 Yes | 6 No |
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