Formal Methods in Conformance Testing: A Probabilistic Refinement

This paper refines the framework of ‘Formal Methods in Conformance Testing’ by introducing probabilities for concepts which have a stochastic nature. Test execution is refined into test runs, where each test run is considered as a stochastic process that returns a possible observa- tion with a certain probability. This implies that not every possible observation that could be made, will actually be made. The development process of an implementation from a specifica- tion is also viewed as a stochastic process that may result in a specific implementation with a certain probability. Together with a weight assignment on implementations this introduces a valuation measure on implementations. The test run probabilities and the valuation measures are integrated in generalized definitions of soundness and exhaustiveness, which can be used to compare test suites with respect to their ability to accept correct, and to reject erroneous implementations

Testing theory in practice: a simple experiment

In this paper we discuss the experiences gained in conducting a simple testing experiment. The goal of this experiment is to apply the abstract, formal testing framework [8] in a practical setting, and to indicate the critical aspects in its application to realistic testing situations. For that purpose a formal description of the system under test (SUT) is made from which tests are systematically derived. These tests are interpreted and executed by a tester against concrete implementations, thereby giving an indication about the correctness of these implementations

The bounded retransmission protocol must be on time!

This paper concerns the transfer of files via a lossy communication channel. It formally specifies this file transfer service in a property-oriented way and investigates -using two different techniques -whether a given bounded retransmission protocol conforms to this service. This protocol is based on the well-known alternating bit protocol but allows for a bounded number of retransmissions of a chunk, i.e., part of a file, only. So, eventual delivery is not guaranteed and the protocol may abort the file transfer. We investigate to what extent real-time aspects are important to guarantee the protocol's correctness and use Spin and Uppaal model checking for our purpose