Process plant operators looking at their existing automation systems are facing pressures from two directions. First, the distributed control system (DCS) platforms controlling those units are getting older and exhibiting age-related problems and failures. Second, newer technologies are capable of extending what those older systems can do. For both these reasons, many plant operators should be making plans for major upgrades or even migration to a completely new system, but large numbers of facilities are trying to push out the inevitable change by scavenging spare parts. Unfortunately, many of the OEMs ceased supporting legacy platforms long ago and may have even gone out of business, so the ability to keep these old systems running is quickly eroding. A serious failure can cause a plant to grind to a halt with no simple means to fix the problem.
The big question for most is how long they can continue before a catastrophic failure. While waiting until the last possible moment may seem like the sound financial approach, it is very risky. It is better to launch an upgrade program long before production hangs in the balance.
The decision to upgrade a DCS is like the decision to upgrade your laptop or PC without pausing your work, but on an enormous scale. Transferring files and programs while learning new PC software is never easy, but using an outdated computer is even more of a chore and it locks you into obsolete technologies. Support becomes harder to find, new programs cannot be used with old operating systems, and speed and storage become major problems. Efficiency suffers as a result.
Of course, migrating to a completely new DCS requires far more extensive planning than upgrading a PC. Fortunately, there are many ways to make it easier to justify and accomplish.