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

11.4 Essential Specification Modelling 343
Unified Model and Requirements Catalogue (textual form).
Figure 11.7 depicts a purpose overview of the elements of the framework.
Static Modelling:
Finding object classes,
relations, attributes,
messages
Essential Behaviour Model Architecture Structure Model
Essential
Object
Class
Diagrams
Scenario Modelling:
Finding objects and their
message interaction
Formal description of system:
Description of process
interconnect structure and
behaviour of all object
classes.
Essential
Message
Flow
Diagrams
Design of process
channel structure:
Structure
transformations
Essential Specification
Essential
Instance
Structure
Diagrams
Essential
Unified
Model
(POOSL)
and
Essential Requirements Catalogue
System Architecture
design: Topology of
interconnected Modules
Architecture
Structure
Diagrams
Adding timing
requirements on
architecture
modules level
Architecture
Response
Time
Requirements
Description of all items in the
models: meaning, purpose;
Description of all requirements that
are not formalised in POOSL;
Description of design decisions.
Figure 11.7: Purpose of SHE Framework Blocks
11.4.2 Graphical and Textual Representations
A specification consists of various kinds of models. They are graphical representations,
text in the form of a natural or formal language, or lists of textual items. Figure 11.8
gives an overview of the kinds of representations that are used in the framework. Notice
that this figure should not be interpreted as the framework of the method.
11.4.2.1 Graphical Representations
The graphical models in Figure 11.8 are divided into Object Models and Structure
Models, see the overlapping dotted blocks. The Object Models are the Object Class Model