Scenario-based specifications such as Message Sequence Charts
(MSCs) are becoming increasingly popular as part of a
requirements specification. Scenarios describe how system
components, the environment and users working concurrently
interact in order to provide system level functionality. Each
scenario is a partial story which, when combined with other
scenarios, should conform to provide a complete system
description. However, it is not always possible to build a set of
components that provides exactly the same system behaviour as
described with a set of scenarios. Implied scenarios may appear as
a result of unexpected component interaction.
In this paper, we present an algorithm that builds a behaviour
model that describes the closest possible implementation for a
specification based on basic and high-level MSCs. We also
present a technique for detecting and providing feedback on the
existence of implied scenarios. We have integrated these
procedures into the Labelled Transition System Analyser, which
allows for model checking and animation of the behaviour model.