Patterns for building Utility Data Models

Cartomaphic design challenges
The cartographic representation of utility objects must be faithful to a long history of manual and digital mapping. Over time, utilities have evolved a set of cartographic practices perform several important functions. They convey rich attribute data on the map and portray small but important objects so that they are not overwhelmed by large geographic objects. These practices also provide specialized map products for distinct audiences such as personnel in customer relations, operations, and engineering.

These are a few of the cartographic problems:

Topologically interesting relationships occur within a very small geographic area. An example is that many devices and lines can be mounted on a single pole, so there is a requirement to draw features such as fuses or reclosers at offset positions and from their true geographic location. Also, sophisticated drawing methods are needed to display line features such as secondary underbuild and parallel circuits.
Many utility systems have multiple networks along the same set of support structures. A common cartographic technique is drawing parallel networks at offsets. Sometimes, annotation or special line styles are employed to denote multiple networks.
An object on a map such as a substation may contain other objects, but it may be represented as a single symbol on a map.

A utility system requires diverse displays of geographic data. Two common types of views are detail (or cartographic) and schematic. Detail map views need to intelligently render network features appropriate to a variety of map scales. Schematic map views are used for studying sectionalizing devices and analyzing voltage drops.

Tabular desire challenges
The essential criterion for handling the attributes of objects well is data integrity. These are some of the actions on data that the modeler would like to prescribe so that editing errors are minimal:

Attributes should be confined to a well specified set or range of values and combinations of values should be compatible. Also, specifying default attributes values is an aid to the editor.
Some objects are bound to each other. The data modeler should be able to specify relationships so that move, copy, and delete edit operations yield the expected result.
There are certain important classifications of feature sets, such as whether they designate underground or overhead, distribution or secondary, or wood or metal.