  Age of Information is an interesting metric that captures the freshness of
information in the underlying applications. It is a combination of both packets
inter-arrival time and packet transmission delay. In recent times, advanced
real-time systems rely on this metric for delivering status updates as timely
as possible. This paper aims to accomplish optimal transmission scheduling
policy to maintain the information freshness of real-time updates in the
industrial cyber-physical systems. Here the coexistence of both cyber and
physical units and their individual requirements to provide the quality of
service is one of the critical challenges to handle. A greedy scheduling policy
called deadline-aware highest latency first has been proposed for this purpose.
This paper also gives the analytical proof of its optimality, and finally, the
claim is validated by comparing the performance of our algorithm with other
scheduling policies by extensive simulations.
