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 rule inhibition graph for each of the plurality of business rules, wherein each rule inhibition graph describes one or more cases that do not satisfy a condition of the rule; building a rules inhibition graph based on the rule inhibition graphs that were built 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; and determining a missing case when a consistent labeling satisfying the constraints of said constraints model is obtained pursuant to labeling of the rules inhibition graph, wherein the missing case is a case that does not satisfy a condition of any of the plurality of business rules.