A new strongly competitive group testing algorithm with small sequentiality

In many fault detection problems, we want to identify all defective items from a sample set of items using the minimum number of tests. Group testing is for the scenario where each test is performed on a subset of items, and tells whether the subset contains at least one defective item or not. In practice, the number of defective items in the sample set is usually unknown. In this paper, we investigate new algorithms for the group testing problem with unknown number of defective items. We consider the scenario where the performance of a group testing algorithm is measured by two criteria: the primary criterion is the number of tests performed, which measures the total cost spent; and the secondary criterion is the number of stages the algorithm works in, which is referred to as the sequentiality of the algorithm in this paper and measures the minimum amount of time required by using the algorithm to identify all the defective items. We present a new algorithm Recursive Binary Splitting (RBS) for the above group testing problem with unknown number of defective items, and prove an upper bound on the number of tests required by RBS. The computational results show that RBS exhibits very good practical performance, measured in terms of both the above two criteria.