Specification of Reactive Hardware/Software Systems - Electronic ...

32 On Specification of Reactive Hardware/Software Systems
To make a specification understandable and readable, the formal specification
language should have an imperative nature.
The method must allow the development of advanced software tools.
The method as well as the formal language must support dedicated modelling
concepts and modelling primitives.
– Behaviour models should be built from process objects. Process objects are
concurrent, self-contained, autonomous, relatively independent and weakly
coupled entities. Process objects have to be grouped into classes.
– Process objects should be connected by channels. It must be possible to group
them into clusters. Clusters have to be organised into classes.
– Information exchange between process objects and clusters must be based on
message passing.
– Process objects must be able to perform various forms of complex communication
behaviour.
– Private data of process objects must be represented by data objects. Data
objects must be grouped into classes.
The method requires an activity framework that guides the development of specifications.
– This framework must be supported by a rich set of guidelines and heuristics.
– The activity framework must allow the different modelling views as well as
the unified model to be developed in a simultaneous, evolutionary fashion. To
avoid confusion between different views, they must be explicitly represented.
– The activity framework must allow the determination of observable behaviour
by considering the internals of a system.
– The activity framework must support the simultaneous development of object
structure and object behaviour. Objects are found by considering conceptual
solutions, by studying the real world, and by outside-in modelling.
– The search for objects and behaviour should be guided by scenarios. Next to
looking for object classes the framework should focus on the search for object
instances.
The activity framework must be supported by behaviour-preserving transformations
that allow a consistent integration of logical and physical structures.
Behaviour-preserving transformations must be expressed in the formal language
and they have to be mathematically proven correct.