Capturing network data by design
Future - Design time capture
With the state of the art AM/FM data now available and fully described in a detailed data model, the
opportunity exists to expand the capabilities of the data collection and maintenance applications to
move beyond simply recording data. It is now reasonable to expect the capabilities to be extended to
fully support the design process which apart from corrections is the only way this change is
introduced. The remainder of this paper examines the nature of the requirements for such a design
facility and considers some of the implications of providing such capabilities.
The first issue to be dealt with is the fact that the design process is radically different to the capture
process, which traditionally mimics the construction process.
The capture process would work in the following order:
-
Definition of the infrastructure such as manholes and trenches
- Definition of the distribution components such as cables and equipment
- Assignment of services.
In the case of the design process, the approach is inverted.
Service requirements must be defined
- Determine the overall capacity requirements
- Dimension of the distribution equipment
- Define appropriate infrastructure components
At many points in the design process, there are decision points which can be supported by suitable
design support tools such as analysis tools or optimisation tools. For example the placement of
expensive amplification equipment must be offset against the cost of providing additional
infrastructure equipment in a broad band network design. Suitable analysis tools can simplify the
process of developing an optimal design.
Inevitably the process of design is one of stepwise refinement. Certain design decisions need to be
deferred until other details are known. For example, the size/capacity of infrastructure components
such as ducts cannot be determined until the cable size is known, and in turn size cannot be
determined until the full extent of the service delivery requirements are known.
The traditional approach to design is to start with an outline sketch and gradually fill in the detail as it
becomes known. This means that the supporting software must be capable of accepting sketch level
details while still maintaining a level of internal model integrity. For most cases this means
maintaining rule sets which are more relaxed during design capture but which can be used to validate
more tightly when a user indicates the design is complete. The software needs to support the user by
indicating those aspects of the design which have not been fully specified. In this way the designer
can work towards a complete solution, with the system providing the necessary integrity rules, but
without forcing the designer into a situation where it expects details, which the designer cannot
accurately provide, at the current stage of the design.
In effect we need to introduce a new "preliminary design" status, which has a much more forgiving
rule set. We also need to provide a new work flow step which allows a designer to upgrade parts of his
design proposal from "pre-design" status to "design" status. This step would apply the more rigorous
rule sets that would guide the designer to any areas that are incomplete from a design perspective. An
example might be an infrastructure component such as a manhole might have a valid size of
"undecided" in "pre-design" stage, which would not be an acceptable size in "design" stage. The rule
set could identify this case when the designer attempted to upgrade the design and either recommend a
valid size, or prompt the designer to provide the necessary size details.
A more supportive approach might be to allow the designer to set the size to "optimal" and have the
system choose the best option when the designer indicates that the design is complete. This approach
to parametrically specifying components, would free the designer from the meticulous task of ensuring
that the correct component was chosen and would allow an approach of "one size fits all" to be
followed. So, for example, the designer would simply specify "underground housing" and the system
would ultimately choose the optimal size and construction type, based upon its usage context.
This concept can be extended to support the introduction of templates and aggregated components,
under such arrangements, whole assemblies are introduced, which consist of a large number of
standard components, or standard configurations, which self-configure based upon the context in
which they are introduced.
