The State Machine Design method that we used doesn’t create the most efficient use of memory or codes. If the computer resources is an additional constraint, we recommend using another sequential logic deign method such as switching tables so the logic it can be reduced via Boolean algebra.
The system can be made more robust by using another PLC to monitor the functions of this PLC and insure that it’s operating correctly.
Adding a HMI (Human Machine Interface) could add a lot more control and provide more information back to the user, such as the Siemens HMIs on display in the ICSE (Industrial Computer Systems Engineering) labs.