Generation of efficient test sequences from LOTOS specifications

LOTOS is a formal description technique (FDT) developed by ISO. This paper proposes a formal technique for generating test sequences from a LOTOS specification. In the proposed technique, test sequences correspond to a finite 'tree' which is represent as a TreeLOTOS expression which is a subset of LOTOS. A labelled transition system (LTS) with variables called VTS is introduced to generate test sequences, which is useful not only for compactness of expression but also for effective selection of test sequences at the execution of tests. Furthermore, the concept of the reduced form of a VTS is introduced and, by using this concept, efficient test sequences can be obtained.