Application of formal methods alone does not ensure safety properties of the systems modeled. This powerful strategy must be complemented by provisions which help to check adherence of the model to the system in question. We propose to use a pattern based approach to increase the structure in formal models of concurrent systems and in this way to make them more easily understandable. The method is applied in a distributed real time specification of a belt component in a production cell which used the HyTech notation. Several specification patterns have been identified; they regard global structure, the use of variable restrictions, of synchronization labels, and the use of locations.