Software product lines (SPL) aim to decrease the total software development cost by the help of reusability and variability. However, the increasing number of variations for the delivery types of products would result in increasing cost of the verification and validation process. Total testing cost of development can also be decreased by reusing test cases and scripts. The main objective of this study is to increase testing effectiveness while minimizing testing effort. Four different cases consisting of Aselsan&rsquo / s SPL projects have been studied. Firstly, FIG Basis path method was applied at the functional testing phase, and an increase on the testing effectiveness value has been observed. FIG basis path method is a test case sequence generation technique using the feature tree of the software component. This method would be preferable to improve testing effectiveness on the functional verification phase. The second study was on testing effort estimation. There are two testing approaches for SPL projects, namely infrastructure based and product focused testing. These two techniques have been compared in terms of testing effort. It was a study that gives an idea to test managers about the selection of the proper testing technique. Thirdly, reusability techniques were evaluated. Reusability of testing artifacts can be used to decrease the total testing effort. Two reusability techniques for testing artifacts were compared in terms of the number of test cases. Proper technique would be chosen to decrease testing effort. Finally, selection of a reference application on platform tests was proposed and software products were grouped according to the redundancy values. Then, testing effectiveness values were evaluated for each test grouping.

Software is all around us in our lives in the industrialized world, and we as a society and individuals need it to function correctly. Software testing fills the role of performing behavior audits, to guide the correction of the software to its intended behavior. The consequences of faulty software can range to the late arrival of trains, to nuclear meltdowns. This places quality requirements on the software of various levels. Program based mutation testing provides a high level of faultfinding capability. It does this by injecting many synthetic faults into the code under test, as described by mutation operators. These faults are used to search for testcases that would identify such faults, and consequently find real faults that the synthetic faults mimic. However, mutation testing is costly on three accounts; each mutant of the original code is compiled, each mutant should ideally have an associated testcase to reveal that fault the mutant contains, finally the testcases are analyzed thoroughly by looking the output of the original and mutants to reveal the error in behavior. In order to reduce cost while maintaining a high level of faultfinding, selective mutation testing is investigated, it uses a subset of all the available mutation operators. The investigation found that using Absolute value-, and Relational operator-, mutation reduces cost of mutation testing by 80%, while uncovering 83% of the injected faults.