Abstract—Model Management addresses the problem of managing an evolving collection of models, by capturing the relationships between models and providing well-defined operators to manipulate them. In this article, we describe two such operators for manipulating feature specifications described using hierarchical state machine models: Match, for finding correspondences between models, and Merge, for combining models with respect to known or hypothesized correspondences between them. Our Match operator is heuristic, making use of both static and behavioural properties of the models to improve the accuracy of matching. Our Merge operator preserves the hierarchical structure of the input models, and handles differences in behaviour through parameterization. This enables us to automatically construct merges that preserve the semantics of hierarchical state machines. We report on tool support for our Match and Merge operators, and illustrate and evaluate our work by applying these operators to a set of telecommunication features built by AT&T.

We support the goals of the workshop to concentrate community efforts towards usable verification. We believe that the keys to addressing this problem are abstraction (i.e., raising the level of abstraction at which the software is designed) and automation (i.e., creating automated and scalable tools for reasoning about such software at the highest

A key problem in model-based development is integrating a collection of models into a single, larger, specification as a way to construct a functional system, to develop a unified understanding, or to enable automated reasoning about properties of the resulting system. In this article, we suggest that the choice of a particular model integration operator depends on the inter-model relationships that hold between individual models. Based on this observation, we distinguish three key integration operators studied in the literature – merge, composition and weaving – and describe each operator along with the notion of relationship that underlies it. We then focus on the merge activity and provide a detailed look at the factors that one must consider in defining a merge operator, particularly the way in which the relationships should be captured during merge. We illustrate these factors using two merge operators that we have developed in our earlier work for combining models that originate from distributed teams.

Abstract—Synthesis of operational behaviour models from scenario-based specifications has been extensively studied. Focus has been mainly on either existential or universal interpretations. One noteworthy exception is Live Sequence Charts which provides expressive constructs for conditional universal scenarios and some limited support for non-conditional existential scenarios. In this paper we propose a scenario-based language that supports both existential and universal interpretations for conditional scenarios. Existing model synthesis techniques use traditional two-valued behaviour models, such as Labelled Transition Systems. These are not sufficiently expressive to accommodate specification languages with both existential and universal scenarios. We therefore shift the target of synthesis to Modal Transition Systems, an extension of Labelled Transition Systems that can distinguish between required, unknown and proscribed behaviour to capture the semantics of existential and universal scenarios. Modal Transition Systems support elaboration of behaviour models through refinement, which complements an incremental elicitation process suitable for specifying behaviour with scenario-based notations. The synthesis algorithm that we define constructs a Modal Transition System that uses refinement to characterise all the Labelled Transition Systems models that satisfy a mixed, conditional existential and universal scenario-based specification. We show how this combination of scenario language, synthesis and Modal Transition Systems supports behaviour model elaboration. Index Terms—Scenarios, MTS, synthesis, partial behaviour models 1

Abstract. In order to capture all permissible implementations, partial models of component based systems are given as at the system level. However, iterative refinement by engineers is often more convenient at the component level. In this paper, we address the problem of decomposing partial behaviour models from a single monolithic model to a component-wise model. Specifically, given a Modal Transition System (MTS) M and component interfaces (the set of actions each component can control/monitor), can MTSs M1,...,Mn matching the component interfaces be produced such that independent refinement of each Mi will lead to a component Labelled Transition Systems (LTS) Ii such that composing the Iis result in a system LTS that is a refinement of M? We show that a sound and complete distribution can be built when the MTS tobedistributedisdeterministic, transition modalities are consistentand the LTS determined by its possible transitions is distributable.