Many types of networks have specifications on the way their features should ,or should not, be linked. An example of these networks is the model of network that the Hierachical Algorithm in Network Analyst needs in order to funcion properly. While building such a network many errors can occur that lead to problematique situatiuons. In my point of view a tool that detects these errors is necessary as a part of the production process during network validation. This was the motivation for writing a paper about the methods and algorithms that can detect this kinds of errors it can be viewed in : http://arxiv.org/abs/1101.5410 Most of the algorithms presented can be implemented in Modelbuilder and I think a convinient way of embending them to ArcGIS would be a tool with similar interface as the Topology tools.