Abstract: A flexible consistency checking mechanism allows network operators to create their own consistency checking rules. Several consistency check formulas are provided. Each formula defines one or more general operations on one or more managed network objects. By applying a general consistency check formulas to one or more specific managed network objects, one or more consistency check rules is generated. For example, the user can generate the consistency check rules simply by inputting certain data values for formula variables by way of a user interface. Once those rules have been generated, they can be used to check the consistency of one or more aspects of a communications network configuration. Each formula also may include a checkpoint that defines a time period or event when a corresponding consistency check rule established using that formula should be executed.