Why stepwise evolution of the plant automation system is more efficient and less costly than other service alternatives
Investment strategies, like corporate mission statements, should be long term. A plant owner’s investment strategy for service and maintenance should begin on the day the plant starts production and end on the day it is decommissioned. Day 1 may strike some as early, but the alternative philosophy of waiting a few years before planning when and which assets to upgrade is too late. By then the assets are already growing old, and a carefully budgeted approach to incremental modernization is slipping out of reach.
There are many benefits to the life-cycle approach.
The first is planning.
Take a plant automation system, for instance. It is an entity that consists of many different parts, both hardware and software. Each part will need to be serviced, updated and upgraded, some at regular intervals, others less frequently. A life-cycle approach will plan when these parts need to be upgraded to ensure that the part and the system continue to perform optimally and efficiently throughout their lifetime.
Second, the life-cycle approach brings structure and order to the service budget.
It makes expenditure predictable and it flattens the cost of maintaining assets over many years. It allows small, incremental upgrades to be made annually in hardware and software to keep the plant running safely and optimally. By making these incremental upgrades, the risk of a part degrading and shutting down the system, or of the system being compromised because of inadequate cyber security, is minimized.
Third, technologies age and become obsolete, some faster than others.
For instance, a vendor may retire an operating system and no longer support it with commercial off-the-shelf software; human machine interfaces become dated and more vulnerable to cyber-attack; without proper maintenance an aging control system may fail and reduce plant output; interfaces between a non-upgraded control system and newer technologies become increasingly difficult to make; and so on. The life-cycle approach eradicates all these issues of aging by updating or replacing the parts before obsolescence and downtime begin.
Fourth, the life-cycle approach avoids the high-cost alternative:
Ripping out the old control system and replacing it with a new one. The cost of installing a new system is rarely what it seems.
Besides the huge replacement of system hardware (I/O, controllers, communication infrastructure, HMI and I/O terminations), there are lots of hidden costs along the way. Control applications have to be re-engineered or translated and new control documentation created; loops have to be retuned, which results in a long commissioning and start-up period; new algorithms result in new and unfamiliar process control behavior; operators and service personnel have to learn a new system, which takes time and requires lots of training; and process graphics, which are the valuable intellectual property of the plant owner, become redundant and have to be replaced.
In short, the risk to production continuity over the short and medium terms is huge.
Fifth, the potential disturbances to production of a changing workforce are avoided.
Over time the workforce at a plant changes. A mature, experienced generation of operators and engineers gradually retires and a new generation takes its place. The new generation may know all the latest technologies but does not have the hands-on experience and intuitive know-how of the older staff. Training is the solution, not piecemeal or ad-hoc, but a planned, long-term training strategy of continuous learning so that the staff can run the plant knowledgably and efficiently.
So, how does the life-cycle approach work in practice?
ABB and the customer together draw up an evolution program that reflects the customer's business goals.
After a comprehensive audit of the existing system, we:
- Submit a long-term plan that addresses near-term goals and that can be reviewed and revised as necessary;
- Identify and target which plants are at the greatest risk for production loss and those that have the greatest potential for increased production; and
- Review the long-term plan periodically and update it as required to reflect changing business needs and new system solutions. This approach takes the guessing out of budgeting.
Such an approach identifies which parts should be upgraded or replaced for the HMI, plant interfaces, engineering tools, optimization, alarm management and DCS interfaces year-by-year over the coming years. And it does so for each plant in the owner’s fleet.