Software integration may also be achieved largely in the host environment, with units specific to the target environment continuing to be simulated in the host. Repeating tests
In the target environment for confirmation will again be necessary. Confirmation tests at this level will identify environment specific problems, such as errors in memory allocation – de allocation.
The practicality of conducting software integration in the host environment will depend on how much target specific functionality there is. For some embedded systems the coupling with the target environment will be very strong, making it impractical to conduct software integration in the host environment.
Large software developments will divide software integration into a number of levels. The lower levels software integration could be based predominantly in the host environment, with later levels of software integration becoming more dependent on the target environment.