1. A method of detecting a missing case of a fixed scope among a plurality of business rules of unrestricted forms, said method comprising: building a rules inhibition graph for the plurality of business rules, said rules inhibition graph representing a constraint model comprising a plurality of nodes and describing a plurality of cases which make the plurality of business rules non- applicable; labeling the rules inhibition graph with values satisfying constraints of said constraint model utilizing search and inference procedures; determining a missing case when a consistent labeling satisfying the constraints of said constraints model is obtained.