embodiments of the invention provide a method , apparatus and article of manufacture for modeling a variety of three - dimensional utility networks constructed from individual network part elements . in one embodiment , users may construct a utility network by selecting and assembling a network of inter - connected parts , where each part is selected from a pipe and structure list . connectivity among parts is established through part placement . structure and connected pipe properties may be managed as a single property set . as parts are placed in the utility network , auto - sizing logic resizes existing structures to connected pipes . pipes and structures are represented by part model data that defines a set of common behavior and properties . when a user modifies part model data or property sets or moves inter - connected parts , a logic component resizes and automatically updates any associated two - dimensional and three - dimensional views of the utility network .