Abstract
This paper is concerned with support for the process of usability engineering. The aim is to use formal techniques to provide a systematic approach that is more traceable, and because it is systematic, repeatable. As a result of this systematic process some of the more subjective aspects of the analysis can be removed. The technique explores exhaustively those features of a specific design that fail to satisfy a set of properties. It also analyzes those aspects of the design where it is possible to quantify the cost of use. The method is illustrated using the example of a medical device. While many aspects of the approach and its tool support have already been discussed elsewhere, this paper builds on and contrasts an analysis of the same device provided by a third party and in so doing enhances the IVY tool.

Abstract
Automation systems according to IEC 61850 are a powerful solution for station automation. Engineering of such distributed systems is however a non-trivial task which requires different approaches and enhanced tool support. In this paper the authors (i) present how IEC 61850 is viewed and is being adopted by a utility and vendor, (ii) discuss its engineering potential and current issues, (iii) point-out global requirements for next generation tools, (iv) present the InPACT project which is tackling some of these concerns and (v) propose key elements of visual languages as one contributing enhancement.

Abstract

Abstract
A transition system can be presented either as a binary relation or as a coalgebra for the powerset functor, each representation being obtained from the other by transposition. More generally, a coalgebra for a functor F generalises transition systems in the sense that a shape for transitions is determined by F, typically encoding a signature of methods and observers. This paper explores such a duality to frame in purely relational terms coalgebraic refinement, showing that relational (data) refinement of transition relations, in its two variants, downward and upward (functional) simulations, is equivalent to coalgebraic refinement based on backward and forward morphisms, respectively. Going deeper, it is also shown that downward simulation provides a complete relational rule to prove coalgebraic refinement. With such a single rule the paper defines a pre-ordered calculus for refinement of coalgebras, with bisimilarity as the induced equivalence. The calculus is monotonic with respect to the main relational operators and arbitrary relator F, therefore providing a framework for structural reasoning about refinement.

Abstract
Tool interoperability as a mean to achieve integration is among the main goals of the international Grand Challenge initiative. In the context of the Verifiable file system mini-challenge put forward by Rajeev Joshi and Gerard Holzmann, this paper focuses on the integration of different formal methods and tools in modelling and verifying an abstract file system inspired by the Intel Flash File System Core. We combine high-level manual specification and proofs with current state of the art mechanical verification tools into a tool-chain which involves Alloy, VDM++ and HOL. The use of (pointfree) relation modelling provides the glue which binds these tools together. © 2009 Springer-Verlag Berlin Heidelberg.

Abstract
The pointfree transform offers to the predicate calculus what the La-place transform offers to the differential/integral calculus: the possibility of changing the underlying mathematical space so as to enable agile algebraic calculation. This paper addresses the foundations of the transform and its application to a calculational approach to extended static checking (ESC) in the context of abstract modeling. In particular, a calculus is given whose rules help in breaking the complexity of the proof obligations involved in static checking arguments. The close connection between such calculus and that of weakest pre-conditions makes it possible to use the latter in ESC proof obligation discharge, where pointfree notation is again used, this time to calculate with invariant properties to be maintained. A connection with the "everything is a relation" lemma of Alloy is established, showing how close to each other the pointfree and Alloy notations are. The main advantage of this connection is that of complementing pen-and-paper pointfree calculations with model checking support wherever validating sizable abstract models.