e information and communications technology industry, in which the compliance of products and the interoperability among products of different manufacturers is nonetheless an essential requirement. However, the creation and conduct of tests, on the one hand can be expensive and not cover all the situations and scenarios specified by the standards, on the other hand, they can reduce the costs to fix a problem in a pre-deployment setting [6]. 8.1.1 Compliance Testing In order to verify the correct implementation of a product and to ensure its working in accordance with the specifications, compliance testing is executed. It is able to increase confidence that a product complies with its specifica- tions, and to reduce risk of malfunctioning when the product is put into place. The compliance testing process can identify product bugs and can ver- ify that the eliminated bugs are fixed successfully and within the applicable standards [7]. In order to execute a compliance testing process for each characteristic of the standard specifications, as shown in Figure 8.1, a test purpose (TP) is written. Next, each TP is revised to detail (1) what is sent to the system under test (SUT), (2) what is expected from the SUT, (3) what the SUT must do in order to pass the test case, and (4) how the SUT can fail the test case. In this way an abstract test case (ATC) is defined and the resulting collection of ATCs forms an abstract test suite (ATS). The implemented ATS becomes an executable test suite (ETS). This last permits the user to select and run one or more test cases from the ATS and save the result in a test report (TR) with a pass, fail, or inconclusive verdict. If the verdict is fail, the product designer can fix the problems found and rerun the ETS [8]. 8.1.2 Interoperability Testing Interoperability testing answers to the question: will this new product or net- work element work with another particular product, or with a class of prod- ucts built according to the same standard? Interoperability testing aims at Standard In