1. A distributed-environment-model checking apparatus, comprising: a memory that stores a set of instructions; and at least one processor configured to execute the set of instructions to: execute, when searching a distributed-environment model by model checking, the search while determining whether or not to postpone execution with respect to a predetermined transition; analyze a dependency relation and a happens-before relation with regard to a plurality of transitions on a path searched, and generate information about backtracking with respect to the path; and generate information about the predetermined transition, execution of which is to be postponed in the search after backtracking executed, based on at least the information generated.