Combining Monitoring with Run-Time Assertion Checking

According to a study in 2002 commissioned by a US Department, software bugs annually costs the US economy an estimated $59 billion. A more recent study in 2013 by Cambridge University estimated that the global cost has risen to$312 billion globally. There exists various ways to prevent, isolate and fix software bugs, ranging from lightweight methods that are (semi)-automatic, to heavyweight methods that require significant user interaction. Our own method described in this tutorial is based on automated run-time checking of a combination of protocol- and data-oriented properties of object-oriented programs

Behavioural Subtyping Relations for Object-Oriented Formalisms

. In this paper we investigate the object-oriented notion of subtyping in the context of behavioural formalisms. Subtyping in OOformalisms is closely related to the concept of inheritance. The central issue in the choice of subtyping relations among classes is the principle of substitutability: an instance of the subtype should be usable wherever an instance of the supertype was expected. Depending on the interpretation of "usable", we obtain a variety of subtyping relations: stronger subtyping relations, allowing one to share the subtype instance among different clients without any change compared with the supertype, and weaker relations, restricting the possibilities of interference of different clients on the subtype instance. The subtyping relations are taxonomically ordered in a hierarchy. The concept of "usability" is formalised via testing scenarios, which provide alternative characterisations for the subtyping relations.