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

38 Concepts for Analysis, Specification and Design
orthogonality of concepts is therefore hard to carry out.
There are many dependencies and relations between concepts. Corresponding to the
different development activities, concepts can be distinguished for:
initial requirements capturing;
functional analysis and specification;
architecture design;
implementation modelling;
hardware/software realisation.
An important condition for a smooth path from product idea to realisation is a clear
mapping between the concepts and descriptions used to support the different development
activities. Descriptions must be consistent and verifiable. A semantic gap between
descriptions often leads, even with today’s CAE/CAD support, to manual translations
of design descriptions. Concepts simply do not match, unless a method is carefully
designed to bridge the gap.
Our specification method as a whole is composed from formal as well as from informal
concepts. The consistency of the formal concepts are verified using a formal semantical
model (see Chapter 7). Unfortunately, such an approach is not directly applicable to
check the compatibility of the informal method concepts. Nevertheless, by establishing
mappings between the informal concepts and the formal ones, we are able to check their
compatibility as good as possible. Using this approach we narrow the semantical gaps
between the different descriptions.
3.6 Practical Use of Concepts
In the previous subsection we stated that the method SHE is the result of the careful
joining of concepts. The concept approach is interesting from a scientific point of view
and therefore it is the most important part of this thesis. A precise description of all
concepts, and motivation for their need, can give a deeper understanding of our work
and the method. However, it is hard to understand the need for concepts without
an understanding of the global ideas for our method. Therefore we present a quick
overview of the use of the method for a real industrial application. This application
is elaborated in Chapter 12. The overview will enable readers which are less familiar
with existing (object-oriented) analysis and design methods to form an idea of the global
flow of a specification modelling process. It will give an understanding for the need
for various concepts that we describe in Chapters 4, 5 and 6. In these chapters we give
small examples that are also derived from the industrial application presented here.