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

342 SHE Framework
In principle both Essential Specification and Extended Specification contain the same
sorts of descriptions. Therefore it is unnecessary to explain them as extensive for both
specifications. We concentrate on an explanation for Essential Specification modelling.
11.4 Essential Specification Modelling
11.4.1 Overview of Representations and Models
Essential Behaviour Model Architecture Structure Model
Essential
Object
Class
Diagrams
P: Class A
Attributes:
Messages:
Relationship x
P: Class B
Attributes:
Messages: m
Essential
Message
Flow
Diagrams
Object o1
(Instance of
class A)
message m
Object
o2
(Instance
of class
A)
Object
o3
(Instance
of class
B)
message m
Essential Specification
Essential
Instance
Structure
Diagrams
Object o1
(Instance of
class A)
Object
o2
(Instance
of class
A)
channel c
Object
o3
(Instance
of class
B)
Essential
Unified
Model
(POOSL)
and
Essential Requirements Catalogue
Architecture
Structure
Diagrams
M1
Figure 11.6: SHE Framework
network
M2
Architecture
Response
Time
Requirements
Figure 11.6 shows that an Essential Specification contains six blocks. The kinds of
graphical notations are visualised in the blocks:
Object Class Diagrams visualise object classes and their relations;
Message Flow Diagrams visualise message flows between collaborating instances
of classes (objects and clusters);
Instance Structure Diagrams visualise the channels between collaborating instances
of classes;
Architecture Structure Diagrams, which are free style graphical representations of
the system’s structure;
Response Time Requirements (textual form);