Automating Test Case Selection in Model-Based Software Product Line Development

We address the problem of how to select test cases for products in a controlled model-based software product line development process. CVL, the common variability language, gives a framework for materialisation of product models from a given base model, variability model and resolution model. From such product models, software products can be derived. In practise, test case development for the product line often is independent from the product development. Therefore, the problem arises which test cases can be applied to which products. In particular, the question is whether a test case for one speci c product can be also used for a "similar" product. In this paper, we show how the expected outcome of a test case to a product in a model-based software product line development can be determined. That is, we give a procedure for assigning the outcome of a given test case on an arbitrary member of a software product line. We recall the relevant de nitions for software product line engineering, describe our approach, and demonstrate it with the example of a product line of super-automatic espresso machines

Categorical characterization of bisimulation

[AM89] and [JNW94] present abstract concepts of bisimulation in terms of category theory. This paper deals with the question how these approaches are related. Futheron it shows how different types of bisimulations on prime event structures can be modelled in terms of the abstract concepts

On completions of semantic domains

This paper adds the technique of chain completion to the setting of [MCB94]. We develop the theory of chain completion Ch(D) of a domain D and show how this completion relates to metric and ideal completion. Especially we study consistency results for denotational semantics on D, Ch(D) and Idl(D)

A Train Protection Logic Based on Topological Manifolds for Virtual Coupling

Virtual coupling is a promising innovation aimed at increasing railway capacity. Compared to current railway signaling systems, it allows two or more trains to run with reduced headway between them. However, such reduced headways are a challenge to safety. In this work we consider this challenge by formally describing and verifying an approach to virtual coupling. We propose a general modeling method based on topological manifolds to describe the protection logic for virtual coupling train control systems. We also describe the basic train control elements in topological terms and analyze the line condition of our virtual coupling logic. We establish that the line condition safety requirements and its representation as a manifold are equivalent and further provide a formal definition of the concept of a movement authority with manifold notations. This allows us to consider the dynamic behavior of trains and a series of theorems that establish the correctness of our protection logic for virtual coupling. Finally, we apply the presented methods to a case study. The results show that the proposed method provides a suitable way to realize a virtual coupling logic safely

An Institutional Approach to Communicating UML State Machines

We present a new approach on how to provide institution-based semantics for communicating UML state machines in form of a hybrid modal logic M↓D. A theoroidal comorphism maps M↓D into the CASL institution. This allows for symbolic reasoning on communicating UML state machines

On two different characterizations of bisimulation

Aczel89 and Joyal94 give distinct characterizations of bisimulation on labelled transition systems in terms of category theory. This paper discusses the differences between their formalisms and shows how to translate these approaches into one another

Automatically Verifying Railway Interlockings using SAT-based Model Checking

In this paper, we demonstrate the successful application of various SAT-based model checking techniques to verify train control systems. Starting with a propositional model for a control system, we show how execution of the system can be modelled via a finite automaton. We give algorithms to perform SAT-based model checking over such an automaton. In order to tackle state-space explosion we propose slicing. Finally we comment on results obtained by applying these methods to verify two real-world railway interlocking systems