In this paper, we discuss a testing method for integration testing of complex and concurrent systems. Integration testing is considered the least well understood and hence is the most problematic level of testing related to concurrent system development. This is so, because integration testing is not completely unit (or code) neither testing nor it is completely system testing. To achieve this goal of improving integration testing, our proposed method exploits architectural specification of concurrent and distributed systems defined in the high level Petri nets, known as Hierarchical Predicate Transition Nets (HPrTNs). More specifically, our testing method implements the separation of concerns strategy to handle both the essential complexity associated with the front-end software development of inherently concurrent and distributed systems, i.e. architectural specification, and the difficulty and cost associated with the back-end development of these systems, namely, software testing.