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

34 Concepts for Analysis, Specification and Design
3.1 Introduction
A method consists of a framework, notations, language(s), heuristics and tools. In the
previous chapters we motivated the need for our research, showed relations with other
research, and defined the requirements for a new method. Instead of refining, combining
and improving existing methods, the goal is to lay down research results that, besides of
a new method, have a more general value. By offering a description of useful concepts
and their possible interpretations and interactions, this work may survive as a base for
future developments of methods.
3.2 Fundamental Approach in Designing Methods
Comparisons of methods as published in books such as [Hut94] and [vdN94] are very
useful for getting some overview on the world of existing methods. For the design of a
new method they are of limited value. Their description appears to be very shallow.
The design of a new method requires a thorough comparison of existing methods. We
looked for a more fundamental approach towards method design. A good starting point
was the work published by Peter Wegner, especially [Weg87] and [Weg90]. This work is
dedicated to the comparison of programming languages based upon the object-oriented
paradigm.
Where Wegner focuses on languages we must cover the broader field of specification and
design methods. A number of useful concepts can be selected from existing methods.
However, most existing methods do not offer adequate concepts that support the specification
of mixed hardware/software systems. To answer to the real need in industry,
concepts must be found that support both mapping to hardware and software implementations.
This broadens the scope of research to concepts for architecture structure,
design heuristics, activity frameworks, and tools.
3.3 Concepts
Concepts must be evaluated on aspects like expressive power, appropriateness, comprehensibility,
applicability, preciseness, etcetera. It appears there is no agreement about
the semantics of many concepts. Interpretations are context and expertise dependent.
Analysis, as we define it, deals with capturing and modelling of a real world and of new
creative ideas to be put in a new product. This cannot be done without a framework
supported by proper concepts. They are required for:
1. an in depth understanding of the essentials of the problem domain, its environment,
its constraints and the required functionality;
2. architecture design and implementation modelling based on constraints, physical
structure and feasibility;