Abstract. In this paper, we propose a method for the derivation of an adaptive diagnostic test suite when the system specification and implementation are given in the form of an extended finite state machine. The method enables us to decide if it is possible to identify the faulty transitions in the system when faults have been detected in a system implementation. If this is possible, the method also returns test cases for locating the faulty transitions. An example is used to demonstrate the steps of the method.
This paper studies the fault detection power of a widely used test suite, i.e., a test suite that traverses each possible transition of each component FSM (Finite State Machine) in the reference system. It is shown that such a test suite is complete, with respect to single output faults of a component under test, if the output of the component is accessible during a testing mode. Experiments have been performed showing that a test suite detecting single outputs faults of each component is good: 92 % of transfer and output faults of the composite FSM are detected.
Abstract-In this paper, we consider a test derivation strategy for testing protocol implementations based on Finite State Machines with timeouts. The strategy is applied for testing TFTP implementations.
Keywords-Finete State Machine (FSM); FSM with timeouts (timed FSM); transition tour
I.INTRODUCTION FSM-based test derivation strategies for conformance testing of protocol implementations are well known [see, for example, 1-3] and a number of formal methods were developed for deriving tests which check time constraints of a discrete event system implementation. Some of them use FSM-based strategies for test derivation [4][5][6][7][8][9][10][11]. One of such strategies uses the model of a timed FSM (TFSM) with so-called timeouts [7][8][9][10][11], i.e., if no input is applied during an appropriate time period the FSM can move to another prescribed state. Correspondingly, the behavior of an FMS significantly depends on a time instance when an input is applied, i.e., the behavior of the FSM is specified for timed input sequences. In [12], it is shown how this behavior can be described by an ordinary FSM with an additional input symbol (a time unit) and thus, despite of the fact that a test suite derived for such an abstract FSM using black-box testing methods returns highly redundant tests, FSM-based test derivation methods can be directly used when deriving tests from an FSM with timeouts. In this paper, we derive a test suite as a transition tour of an appropriate FSM, since W-based testing methods [3] ask for the specification FSM to be complete and deterministic and this usually does not hold for FSMs which describe protocol behavior. We then analyze the fault coverage of a transition tour for TFTP (Trivial File Transfer Protocol) [13] implementations where the behavior significantly depends on timeouts. The contributions of the paper can be summarized as below.
Design For Testability (DFI') is understood as the process of introducing some features into a protocol entity that facilitate the testing process of protocol implementations. DFI' at the implementation level deals with a particular realization on a given platfonn, whereas DFI' at the specification level affects all possible implementations regardless of the implementation process. The fact that protocols are usually specified only partially, facilitates DFI' at the specification level. In this paper, we address one particular problem of DFI', the problem of finding a minimal augmentation of the given protocol behavior (an FSM) such that a newly obtained specification is more testable than the original one, while maintaining sets of defined states and events. We propose an approach to augmenting a partially specified FSM such that a test suite for the resulting FSM with guaranteed fault coverage is shorter than that for the original FSM.
In this paper, we consider the problem of detecting faults within a component of a system of communicating FSMs. These faults are detected by a given set of external test cases, which satisfy appropriate test purposes. Given a component FSM and an external test case, we propose a procedure for deriving the set of all output faults of the component machine, which can be detected with this test case. Applications range from test suite minimization to derivation of diagnostic tests for a component FSM. In this paper, we use the above technique for augmenting a given test suite in order to detect all output faults within a component under test. The same approach can be used with respect to any other finite set of faults within the implementation of a component FSM.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.