Guenter Hilmer - Phd Thesis - Glamorgan Dspace - University of ...

4.1 General approach 4 HEAT
4.1.2 Design aspects
The general technical aspects pointed out in 4.1.1 were applied to the design of
the HEAT. The following design aspects were applied during the development of
the HEAT:
• Object Oriented Design
The HEAT was implemented by using Borland JBuilder3 and Java2 [168][170]
and by applying an object oriented approach. Additionally, the design of the
HEAT is based on classical object oriented design patterns. This approach
facilitates the extensibility of the HEAT. For example, if a new TLS needs
to be added, it just has to implement the pre-defined interfaces and methods
of the HEAT framework and it can be used. Furthermore, an object oriented
approach was considered to be more feasible for the implementation of the
HEAT, which consists of 15 different java-classes at the moment.
• Top-Down Design
For the implementation of the HEAT it was necessary to decide how to con-
vert the EFTECS into an application regarding the layers of the EFTECS.
There were two possibilities, either a top-down approach that uses the EM-
layer as the working space of the HEAT or a bottom-up approach that fo-
cuses on the individual EHPs. During the implementation process it proved
to be more feasible to use a top-down approach for the implementation.
• Representation of the EM-layer
The working frame of the HEAT represents the EM-layer of the EFTECS.
Every TLS and every EHP that is created within the working frame is a part
of the actual EM.
• Representation of the TLS-layer
The TLS instances are symbolised by rectangles that are added to the work-
ing frame of the HEAT and therefore to the EM. The TLSs can be created,
edited and deleted by mouse or keyboard inputs.
• Representation of the EHP-layer
The EHP-layer of the EFTECS is represented by the single elements within
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