This paper introduces a multi-level testing strategy called
bottom-up reuse that can be applied to the mentioned functional
cores in order to reduce the effort needed for testing along the entire test process. Bottom-up reuse enables systematically reusing test
specifications, test designs and even test implementations across
multiple test levels. With bottom-up reuse, all these artifacts focus
on testing the functional core, thus omitting details about the
implementation of the function under test within the system. Apart
from reducing the test effort, bottom-up reuse leads to shared test
artifacts, promoting collaboration between teams at different test
levels.