The Case for Verification of Systems

System verification covers the many components that comprise the system; these include the individual components, their integration as well as a control system, if provided. Large complex systems may have many individual functions repeatedly implemented. The implementation of system logic in software, pneumatics, hydraulics and hardwired interconnected electromechanical relay is explored in this paper. It is suggested that the definition of software is more than simply code executing within a programmable electronic controller (PEC), especially when system control includes control loops utilizing PID control with optional cascade and/or feed forward control, Kalman Filtering, etc. that are themselves executing within the PEC or in other control devices external to the PEC. This paper reviews the importance of systematically analyzing systems for the purpose of developing a verification scope that can reasonably be implemented, while constrained by time and cost, recognizing that not all defects can be identified.