In case of device and communication failures, a basic process control using Foundation Fieldbus technology can be configured to provide either safety improvement for preventing hazards or availability enhancement for minimizing production losses. The purpose of this paper is to introduce a system modeling with Petri Net technique for representing the behaviors of the proportional-integral-derivative (PID) and cascade loops with ‘Control in the Field’ (CIF) and ‘Control in the Host’ (CIH) architectures in response to instrument and communication failures. The proposed modeling is useful for performance analysis of the interested control loops in terms of safety and availability improvement. Stakeholders of both brownfield and greenfield projects in process industry sector can select a proper solution to their necessary performance requirements.