Dynamical Effects in Control Systems

Nasty dynamical phenomena in single processor control systems have been reported on in recent papers. Queue lengths may show heavy oscillations due to so called traffic synchronization effects caused by an inappropriate priority scheme. In this pa.per we give a brief summary of these investigations. We then report on single processor systems where traffic synchronization effects may arise'due to job having to be served several times. Finally we show that in multiprocessor control systems similar effects can be caused by the mechanism that distributes jobs to processors.