Agile uses proprietary procedures and best practice methods to reduce downtime and risk in a migration. It's possible to have downtime, on a major system, minimized to less than a day. A big advantage is that we program in a development area and use smart simulated logic to mimic field variables like temperature, levels, pressures, valves, and motors. This allows for full function test and evaluation, as well as an operator test drive.
You should be looking into migration if:
Hardware is discontinued
Operating system security issues
Limited flexibility for additional functionality
Your PLC is 20 years old or older
PLC5 and SCL500 PLC hardware has already reached the end of its life.
Other obsolete PLC System: Siemens S7-300, MODICON, AUTOMATIONDIRECT, Micrologic 1000/1200/1500. Some PLCS require obsolete operating systems to function in many cases these old Operating Systems are banned by IT departments.
Replacing these obsolete systems can be painful if it's not carefully planned out.